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NUTRITIVE VALUE

OF POLLOCK FISH SCALES
AS DETERMINED BY

RAT FEEDING TESTS

SPECIAL SCIENTIFIC REPORT-FISHERIES No. 260

UNITED STATES DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE

EXPLANATORY NOTE

The series embodies results of investigations, usually of restricted
scope, intended to aid or direct management or utilization practices and as
guides for administrative or legislative action, It is issued in limited quantities
for official use of Federal, State or cooperating agencies and in processed form
for economy and to avoid delay in publication.

United States Department of the Interior, Fred A. Seaton, Secretary

Fish and Wildlife Service, Arnie J. Suomela, Commissioner

NUTRITIVE VALUE OF POLLOCK FISH SCALES

AS DETERMINED BY RAT FEEDING TESTS

by

Donald G, Snyder
Biochemist

and

Hugo W. Nilson
Supervisory Chemist

Special Scientific Report--Fisheries No. 260

The Library of Congress has cataloged this publication

as follows:

Snyder, Donald Graeff, 1926-

Nutritive value of pollock fish scales as determined by rat
feeding tests, by Donald G. Snyder and Hugo W. Nilson.
;Washington, U. 8. Dept. of the Interior, Fish and Wildlife
Service, 1959,

ll p. diagr. 27 em. (U.S. Fish and Wildlife Service. Special
scientific report: fisheries no. 260)

Bibliography: p. 9.

1. Seales (Fishes) 1. Nilson, Hugo Waldemar, 1901— joint au-
thor. ou, U. S. Fish and Wildlife Service, m1. Title. (Series)

SH11.A335 no. 260 636.087 59-60216

Library of Congress

The Fish and Wildlife Service series, Special Scientific

Report--Fisheries, is cataloged as follows:

U.S. Fish and Wildlife Service.
Special scientific report : fisheries. no. 1—
; Washington, 1949-

no. illus., maps, diagrs. 27 cm.

Supersedes in part the Service’s Special scientific report.

1. Fisheries—Research.

SH11.A335 689.2072 59-60217

Library of Congress

ABSTRACT

Rat feeding studies have indicated that pollock fish
scale protein is as well digested but about 30 percent less
assimilated than a protein supplement consisting of 3 parts
casein and 1 part lactalbumin. Fish scales as the only
source of 9 percent protein in the diet are incapable of
supporting growth of young rats, but the scales can be utilized
as a limited source of protein when supplemented with casein-
lactalbumin protein, Increased utilization of scale protein
in combination with stepwise higher levels of casein-lactalbumin
indicate that no toxic substances per se are present in scales

for growing rats.

CONTENTS

Page

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INTRODUCTION

During the past few years, the fishing industry has been
confronted with the increasingly difficult problem of annually
disposing of thousands of tons of fish scales, as fillets have re-
placed unprocessed fresh fish in sales volume, Harbors nearby to
plants normally allow for an inexpensive area of scale disposal, but
unless tidal flows are strong, pollution may result.

Attempts to use the scales as fertilizer on local farms
have been unsuccessful, and the incineration of scales would be
costly. Chemical engineers and pharmaceutical houses have been asked
for suggestions for utilizing the scales, but this approach, too,
has been unsuccessful. In order to determine whether the scales may
have value as a source of protein in farm-animal diets, the nutritive
value and some factors affecting the nutritive value of the nitrogen
compounds in whole scales are being studied,

Part of this work--rat-feeding studies to compare the
nutritive values for growth, the biological values for maintenance,
and the digestibilities of pollock fish scale and of casein-lactalbumin
protein--is reported herein. The nitrogen content of pollock scales
is equivalent to about 60 percent crude protein (N x 6.25).

Very little research has been conducted with fish scales in
the past, and none has been conducted that would promise a solution to
the proposed problem. For many years, however, investigators have
been studying the nutritive value of similar biological materials,
Meunier et al. (1927), Routh and Lewis (1938), and Routh (192a, 19)2b)
have investigated the nutritive possibilities of wool, and Wagner and
Elvehjem (192, 193) and Newell and Elvehjem (197) have investigated
the nutritive quality of some waste keratins. The nutritive values of
meal from untreated and treated chicken feathers have been studied by
Routh (192b), Binkley and Vasak (1950), Wilder et al. (1955), Feedstuffs
(1956), as well as others.

In general, these studies have indicated that scleroproteins
are nutritionally inadequate but can be used as a partial source of
protein with proper supplementation. As far as is known, no studies
have been conducted to determine the feed value of fish scales, the
scleroprotein now being considered.

MATERIAL AND ANALYSIS

The fish scales used in this study were kindly furnished by
the staff of the Fishery Technological Laboratory, J. S. Bureau of
Commercial Fisheries, Hast Boston, Massachusetts. Pollock (Pollachius
virens) were scaled by hand. The scales were washed with water,
drained, spread in pans, and dried in an oven at 100° C, They were
shipped to this laboratory, where they were ground as finely as possible

in a coffee grinder. An analysis of the particle size of a typical
batch of ground scales showed that 3 percent were caught on a 20-mesh

U, S. Standard screen, 19 percent on a O-mesh, 36 percent on a 60-mesh,
18 percent on a 80-mesh, and 7 percent on a 100-mesh, and that 17
percent passed through a 100-mesh screen.

The moisture, protein (N x 6.25), fat, and ash of representa-
tive samples of scales from the various lots showed no great variation.
The mean and ranges of moisture content of )) lots of scales were ).)
percent and 1.0-6.9 percent, respectively; of protein content of 11
lots, 59.5 percent and 56.6-62.5 percent; of fat content of ) lots,
0.00) percent and 0.0-1.0 percent; and of ash content of 5 lots, 38.9
percent and 36,1-3.1 percent. Association of Official Agricultural
Chemists (1955) methods of analyses were used.

No significant differences in the nutritive value of the scale
protein were found among lots. The small differences in moisture,
protein, fat, and ash contents of the scales probably can be attributed
to the nutritional status and age of the fish from which the scales were
collected (195).

EXPERIMENTAL

Postweaning rats were fed diets containing a total of 9
percent protein from pollock fish scales (PFS) or a protein supplement
of 3 parts casein and 1 part lactalbumin (CL)in stepwise substitution,
on an equal nitrogen basis, of the PFS protein, namely, 2.25, .50,
and 6.75 percent. In addition, the CL was also fed alone at these
three levels of protein, as well as at the 9 percent level.

The basal diet had the following composition: lard, 8; cod-
liver oil, 2; salt mixture U.S.P. XIV, No. 2, for vitamin-A bioassay,
hs and dextrin, 86 parts by weight. To every 100 g. of the basal
diet were added 100 mg. of choline chloride, 15 mg. of alpha tocopherol,
and 75 mg. of the following vitamin mixture: thiamine HCl, 1; riboflavin,
23; pyridoxine, 1; Ca pantothenate, 10; nicotinamide, 10; inositol, 5;
para-aminobenzoic acid, 30; biotin, 0.05; folic acid, 0.2; menadione,
14.23 and ascorbic acid, 2 parts by weight. Vitamin By) was supplied
to the rats by adding 0.2 ml. of a 0.005 percent aqueous solution to
individual 250 ml. water bottles every time they were refilled. The
ground PFS and CL were incorporated into this basal diet at the expense
of dextrin.

Four highly inbred black-hooded rats, two males and two
females, were allotted to each group. The males were allotted at
initial live weights of 9 to 53 and the females at 8 to 50 g.
Litter-mates were randomly distributed among the various groups, but
never more than one to any single group.

The rats were housed individually in wire-screen cages
fitted on wire=mesh floors. The temperature of the room was maintained
at 80° F, The rats were supplied with food and water ad libitum, and
weekly records were taken of live weight and food consumption, The
feeding study lasted 10 weeks. The apparent digestibilities of the
protein consumed by individual rats were determined in aliquots of the
ground, debris-free feces, collected during the fourth and fifth week
of the feeding test.

Four adult male albino rats, two each fed PFS and CL protein,
were used to determine the biological value for maintenance, according
to the method proposed by Mitchell (192). The rats were housed in
cages on wire screens, over funnels into which a small wire screen
was inserted to catch feces and allow urine to pass. Urine was col-
lected in 600 ml. beakers under toluene, and a few ml. of a 3-percent
solution of 430 was used as additional preservative. The feces were
collected fron tHe small screens and separated from food, hair, and
other debris, and were ground. Nitrogen was determined in measured
aliquots of the urine and feces,

The non-nitrogenous diet fed to the rats contained: dextrin,
60; sucrose, 21; salt mixture U.S.P. XIV, No. 2 for vitamin-A bioassay,
ls lard, 13; and cod-liver oil, 2 parts by weight. To each 100 g. of
this basal diet was added 0.072 and 0.2h0 mg. of thiamine and riboflavin,
respectively, The test protein vas incorporated into a li-percent agar -
10-percent sucrose gel mixture. A 3-day precollection and a 2-day
collection nonprotein-feeding period; a 3-day precollection and a 3-day
collection protein-feeding period; followed by a second 3-day precollection
and a 2-day collection nonprotein-feeding period was used. The quantity
of test protein fed daily during the protein-feeding period was equivalent
to the nitrogen contained in the urine daily during the first collection
period.

RESULTS AND INTERPRETATIONS

The data in table 1 and figure 1 indicate that the male and
female rats fed the diet containing 9 percent protein from PFS alone
lost considerable weight and died before the eighth week of the study.
The rats fed the basal diet with no added protein lost about the same
weight and died at about the same time. Evidently 9 percent PFS protein
did not permit growth any better than no protein added to the basal diets.

The mean gain of 135.9 g. of the group of rats fed the diet
containing 9 percent CL protein, indicates that CL was more efficiently
utilized than the various other 9 percent protein combinations of PFS-CL
contained in the diets (table 1), The mean gain of the group of rats
fed this diet at the end of 10 weeks, however, was not statistically
significantly different (p=> 0.05) from that of the group fed the diet
in which 2.25 percent PFS protein replaced a like amount of CL protein,

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namely, 117.5 g. Therefore, inclusions of up to 25 percent protein
from PFS in place of equal amounts of CL, as the sole source of protein,
and at a total level of dietary protein of 9 percent, does not adversely
affect the nutritive value of the protein for growing rats. Itis
interesting to note that the males grew better than the females when
fed the diet containing 9 percent CL protein, which would be expected,
but grew similarly when fed the diet containing 2.25 percent PFS and
6.75 percent CL protein, which would not be expected, since the mean
gains of the two groups were not statistically significantly different.
This observation might indicate that the males and females differ in
their ability to utilize the PFS protein in this combination with CL
protein,

The mean weights at 10 weeks of the group of rats fed the
diets containing 6.75 percent PFS and 2.25 percent CL protein (15.3 g.)
and )|,50 percent CL protein alone (23.8 g.) also were not statistically
significantly different (p => 0.05). All of the mean weights of the
groups of rats fed the other diets were statistically significantly
different (p =<0.01) for the 10-week period. The coefficients of
variation generally were smaller than usual for this type of a feeding
study (9 - 12 percent).

Although the group of rats fed the diet containing 9 percent
PFS protein alone died, the different groups of rats grew increasingly
better when they were fed diets in which 2.25, ).50, and 6.75 percent
of this PFS protein was replaced by equal amounts of CL protein, This
increased growth was apparently directly correlated with the stepwise
higher levels of CL protein in relation to PFS protein in the diet.
However, the rats fed diets containing these increasing levels of CL
protein alone in the diet did not grow as well as rats fed these same
diets containing, in addition, the decreasing levels of PFS protein
to make a total of 9 percent protein, This added growth with PFS
protein indicates that the PFS protein certainly was being utilized.

An increase of 31 g. in mean gain was obtained when the group
of rats was fed the diet containing 6.75 percent PFS and 2.25 percent
CL protein over that obtained for the group fed the diet containing
2.25 percent protein from CL alone. This increased growth cannot be
the result of the added PFS protein or the low level of CL protein,
since rats fed diets containing these levels alone did not gain weight.
Apparently, the 2.25-percent level of CL protein was ample to balance
the 6.75 percent PFS protein.

An increase of 73 g. in mean gain was obtained when the group
of rats was fed the diet containing )).50 percent PFS and );.50 percent
CL protein over that obtained from the group fed the diet containing
h.50 percent CL protein alone. This greater growth of rats fed a diet
containing an even lower level of PFS protein sugzests that the PFS

sed)

protein was more completely balanced by the additional CL. (in this
case, CL protein could be used for growth when fed alone in the diet
at this low level and the PFS protein might be envisioned as contri-
buting additional nutrients.

An increase of 3); g. in mean gain was obtained when the
group of rats was fed the diet containing 2.25 percent PFS and 6.75
percent CL protein over that obtained for the group fed the diet
containing 6.75 percent CL protein alone, This increased growth of
3h g. is not as great as when the previous pair of diets are compared,
namely, 73 g. This result is to be expected, inasmuch as there was
less PFS protein in the diet and the nutritively superior CL protein
was present in sufficient quantity to permit ereater utilization. It
is interesting to note that there was a relation of nearly 1:2:1
(31, 73, 3 g.) for the increased growth when the three pairs of diets
were fed. This might indicate that the balancing values of the two
proteins vary when different levels of each were included in the diets.

The data in table 1 indicate, in general, that as the rats
grew better less protein was required per unit gain in weight. This
decreasing requirement for protein suggests that increasing amounts
of CL protein permit the rats to utilize the PFS protein more efficiently.
When this index, as well as the previously compared growth rates, is
used as the criteria for PFS protein utilization, trends of data indicate
that no toxic substances per se are present in the fish scales.

The data in table 2 indicate that the mean apparent digesti-
bility of PFS protein was about 80 percent when fed at the 9-percent
level in the diet. The data also indicate that this level of digesti-
bility was not statistically significantly increased (p =) 0.05) when
the rats were fed diets in which the CL protein was substituted in
part or in whole for 9 percent PFS. :

The increase in digestibility of diets containing the smaller
to greater levels of CL protein alone is interesting. It may be that
as the rats ingested the stepwise higher levels of food nitrogen, the
residual metabolic products eliminated in the feces, as well as the
digestibility of the CL protein remained equal. Hence, the ratios of
ingested food nitrogen divided by the unabsorbed food nitrogen plus
residual metabolic nitrogen would increase. There would be an error
in calculating the digestibility of the protein for rats fed a diet
containing a small amount of protein which would restrict food intake
and limit growth compared with those obtained for rats fed a diet
containing an adequate level of protein which would result in increased
food intake.and greater growth,

Biological values for maintenance of 61.2 and 61.1 were gotten

for PFS protein with two sets and, similarly, 85.3 and 89.) were gotten
for CL protein, The CL protein appears to be utilized about 30 percent

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more than PFS protein. True digestibilities determined in this test
indicated that both PFS and CL protein were completely digested,
Whereas the apparent and true digestibility of the two proteins by
rats are similar, quite different assimilation is indicated by the
biological values,

DISCUSSION

Investigators studying the nutritive value of other waste
scleroproteins have concluded that they are nutritionally inadequate,
but can be used as a partial source of protein with proper supplementa-
tion, This conclusion is also true with pollock fish scale protein.

Rats fed a diet containing 9 percent protein from PFS alone
lost considerable weight and died in about 8 weeks. Rats fed diets
containing PFS in combination with stepwise higher levels of CL protein,
for a total dietary protein level of 9 percent, however, utilized the diet
for growth increasingly better. These rats also grew better than those
fed the stepwise higher levels of CL protein alone in the diet. In
general, as the rats grew better they utilized the food for growth more
efficiently.

Routh (192a, 192b), Wagner and Elvehjem (192, 193), Newell
and Elvehjem (197), Wilder et al. (1955), and others showed that the
various nutritively deficient scleroproteins could be utilized or
balanced with proper supplementation, but in general they did not
indicate that this utilization or balance could be improved when greater
levels were included in the diets. In most cases the supplementations
consisted only of empirical amounts of amino acids added to the diet
in order to find out which acids alone or in combination permitted
better utilization of the scleroprotein.

The rats fed the diet containing a 9-percent level of protein
from CL alone grew better than rats fed any other 9 percent protein
combination of PFS and CL protein. At this level of protein in the
diet, at least, CL protein must be better balanced in nitrogen nutrients
than the protein from any of the combinations, Thus, the growth of
rats fed diets containing increasing levels of PFS protein in relation
to fixed levels of CL protein was less and less, Toxic factors, per se,
in the scales must be ruled out, because there then would be no varia-
tion in the utilization of PFS protein by the rats. Furthermore, there
were no visible symptoms of toxicosis.

The protein of the fish scales is digested sufficiently
well so this cannot be an important factor in explaining the effects
noted. The results showed that, at the 9-percent level in the diet,
both PFS protein and CL protein were about 80 percent digested when fed
to rats. This high level of digestion indicates that the incomplete,
probably imbalanced, PFS protein had been absorbed to a considerable
extent and was available for metabolism. The utilization after

absorption, as shown by the biological values, is quite dissimilar,
however. This difference in utilization may suggest that better
assimilation of this protein, that is utilization, is responsible,
at least in part, for the greater nutritive value of PFS in combina-
tion with the stepwise higher levels of CL protein. Apparently the
PFS protein is more completely utilized when the higher levels of CL
are fed because the protein furnished by CL supplies more and more
of the lacking amino acids or other nitrogen compounds.

The problem remains as to the value of more commonly avail-
able sources of protein to supplement PFS protein as feed, and the
ability of other species of animals to metabolize this protein,

SUMMARY AND CONCLUSIONS

Postweaning rats were fed diets containing pollock fish
scales (PFS) or a protein supplement of 3 parts casein and 1 part
lactalbumin (CL), The latter also was fed at three levels of protein
in stepwise substitution of, as well as in place of, the pollock
scales, Apparent digestibilities of protein by individual rats were
determined in diets fed during this feeding study. The biological
value for maintenance and true digestibility was determined for PFS
and CL protein.

The data indicate:

1. The mean apparent digestibility is 80 percent when PFS
protein is fed at a 9-percent level in the diet to male and female
rats, This value of digestibility is not significantly increased
(p => 0.05) when rats are fed diets in which the CL protein is sub-
stituted in part or in whole for the 9 percent PFS. PFS and CL
protein is completely digested, as indicated by true digestibility
values, when only enough is fed to equal metabolic nitrogen.

2. A level of 9 percent PFS protein as the only source of
protein in an otherwise adequate diet is incapable of supporting
growth in young rats. This nutritional inadequacy of PFS protein is
likely due to a deficiency and/or imbalance of specific nitrogen
nutrients.

3. PFS protein can be utilized by rats as a limited source
of protein for growth when supplemented with CL protein in the diet.
Decreasing ratios of PFS to CL protein in the diet permit progressively
better utilization of the PFS protein,

h. No toxic substancesper se are present in pollock fish
scales for growing rats.

5. The biological value of PFS protein for maintaining rats
is about 60 percent; which is about 30 percent less than for CL
protein,

ACKNOWLEDGEMENTS

The authors wish to thank Mr. Robert Kifer for his assistance
in caring for the animals, and Mrs. Sue Nealis for her assistance in
the statistical analysis of the data.

LITERATURE CITED

ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS
1955. Official methods of analysis, 8th ed., Washington, D. C.

BINKLEY, CHARLES H., and OTTO R. VASAK
1950. Production of a friable meal from feathers. AlC - 27h,
Bureau of Agricultural and Ind. Chem., Agr. Res. Admin.,
U.S.D.A.

FEEDSTUFFS
1956. Feathermeal used as a source of protein for lambs, vol.
285. *Deel.

MEUNIER, L., P. CHAMBARD, and H. COMTE
1927. Sur la digestion pancreatique de la laine. Compt. rend.
acad., vol. 18), pp. 1208-1210.

MITCHELL, H. H.
192h. A method of determining the biological value of a protein.
J. Biol. Chem., vol. 58, pp. 873-903.

NEWELL, G. W., and C. A. ELVEHJEM
1947. Nutritive value of keratin, III. Effect of source, particle
size, and method of grinding. J. Nutrition, vol. 33, pp.
673-683.

NISHIHARA, HATASU
195. Calcium oxalate content of fish scales. Science Rept.,
Saitama University Ser. B, vol. I, pp. 159-16).

ROUTH, JOSEPH I.
1910. Chemical studies on powdered wool. J. Biol. Chem., vol.
1355 PPe 175-181.

ROUTH, JOSEPH I.
192a. Nutritional studies on powdered wool, J. Nutrition, vol.
2335 DPpe 125-130.

ROUTH, JOSEPH I.
192b. Nutritional studies on powdered chicken feathers. J.
Nutrition, vol. 2h, pp. 399-loh.

ROUTH, JOSEPH I., and HOWARD B. LEWIS
1938, The enzymatic digestion of wool. J. Biol. Chem., vol. 12h,
pp ° 725-732 °

WAGNER, JOSEPH R., and C. A. ELVEHJEM
192, Nutritive value of keratins. I. Powdered swine hoofs,
Proc, Soc. Exp. Biol. Med., vol. 51, pp. 39-396.

WAGNER, JOSEPH R., and C. A. ELVEHJEM
1943. Nutritive value of keratins. II. Powdered swine hoofs in
poultry rations, Poultry Science, vol. 22, pp. 275-276.

WILDER, O. H. M., PAUL C. OSTBY, and BARBARA R. GREGORY
1955. Whe use of chicken feather meal in feeds. Poultry Science,
vol. 3h, pp. 518-52).
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Table 2

Mean apparent digestibility of the proteins in the diets fed to rats to
compare pollock fish scale and casein-lactalbumin protein

Mean % apparent digestibility

Diet désignation males
males females and females 3.E.2/ c.v.2/

PFS, 9.00% 83.7 (563 7925 2.82 U
PFS, 6.75%-CL, 2.25% 76.3 76.8 76.5 iLgs}n 4
PFS, ).50%-CL, 1.50% 80.6 80.8 80.6 125 3
PFS, 2.25%-CL, 6.75% (Darl 81.3 80.h 1.50 h
CL, 9.00% 8).3 83.1 83.8 0.89 3
PFS, 0200%-CL, 0.00% = = = = eS
CL, 2.25% 62.9 L7.4 55.2 eile) 20
CL, 4.50% 706 75.28 7302 S55 hh
CL, 6.75% 80.0 78.6 7902 16 11

V/ Standard error of the mean for gain in weight for the group of male and
female rats.
2/ Coefficient of variation in % for the group of male and female rats.

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BACKGROUND INFORMATION
FOR VOLUNTARY GRADE STANDARDS
ON NATURAL SPONGES

SPECIAL SCIENTIFIC REPORT-FISHERIES No. 273

UNITED STATES DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE

EXPLANATORY NOTE

The series embodies results of investigations, usually of restricted
scope, intended to aid or direct management or utilization practices andas _
guides for administrative or legislative action. It is issued in limited quantities —
for official use of Federal, State or cooperating agencies and in processed form» Ne
for economy and to avoid delay in publication. a

United States Department of the Interior, Fred A. Seaton, Secretary
Fish and Wildlife Service, Arnia Je Suomela, Commissioner

BACKGROUND INFORMATION FOR VOLUNTARY GRADE STANDARDS

ON NATURAL SPONGES

By Robert B. Bennett

For the Bureau of Commercial Fisheries
United States Fish and Wildlife Service

Contract No. Lj-19=008=2378
University of Florida Project No. 5527

Department of Chemical Engineering
Engineering and Industrial Experiment Station
University of Florida
Gainesville, Florida

Special Scientific Report--Fisheries No. 273

Washington 25, De Ce
May 1958

The Library of Congress has cataloged this publication
as follows:

Bennett, Robert Broadhurst, 1909-
Background information for voluntary grade standards
on natural sponges. Washington, U.S. Dept. of the Interior,
Fish and Wildlife Service, 1958.

GO p. ius. 27 cm. (U.S. Fish and Wildlife Service. Special
scientific report : fisheries, no. 273)

Includes bibliography.

1. Sponges. 1. Title. (Series)
SH11.A835 no. 273 639.7 59-60428

Library of Congress

The Fish and Wildlife Service series, Special Scientific
Report--Fisheries, is cataloged as follows:

U.S. Fish and Wildlife Service.
Special scientific report: fisheries. no. 1-
,Washington, 1949-

no. illus., maps, dlagrs. 27cm,
Supersedes in part the Service’s Special scientific report,

1. Fisheries—Research.
SH11.A835 639.2072 59-60217

Library of Congress 12)

TABLE OF CONTENTS

Introduction SPoSSHSHHSHS LES EOCLCe LEH L ELE LTO LOLOL ESL OOO SOLO COOH OOCO®S
References e@eeenoesee eves eeeeaeeeooeveaeeeeeeeeseGeeeeeoneeeee2e2ee2020080
WHaCESDONEERUSCLS WAN bi sis ciclo ole! siole elsleleleicioielsielere clelersioicicicisletslereiers

Desert ptevon Of important SPONGES ss eleisiciciers ce cleleiole cleieicicicisicisieveioreice
Inshore and Rock Island @eeeeeeeeeooneeeeeeeeoeoeoeeoeeeovoeveeeneeoo260
Bengasi Mediterranean and Deepwater Mediterranean ecccccececcee
Florida Key Wool or Sheepswool @eeeeeveeseeSeooeeoesoeoeeeneeoeoee200@
Cuban Sea Wool @eeeseeeeeeeseeeeeeeea Ge eoeeveeoeseoonooeeeeaesoeoeonee
Florida Yellow S@eeeeeeeoeeeeeeaeoeeoeeeeeeene Goseeseoseooneeeeoeesoeoeee
mncloterGrasssand Huds On" Grassi veisicleselelelelelercielelcielevelelsieie cicleveisterete

Grading systems @ecoceeeeveeeeeceeoeeeeoeeecoeeeeeoneeeoeoeoeoe ove es ee e202 ed
Present system of grading ee@eeaneeeeeceeveoeeneeoeneeeesO2eeoe2e00220008680
Demerit system of grading @eoeceeroeoseeeeoeanvnvnee e200 080808088000880 8080086

Discussion of faults @eeseeeeeneeeeeGeeoeeeoeoaneeeoeeoeaeeooeedeaseoeeeoee oe
Major faults @eeeevoeveseeeeeOaceeoeeseeaeoeaoee see eeoeeocoeeoeoneoeeoeeeeeded

Bleached @eceoaeseeeeeeecveeeseeeveeeveeoeeeeeneooeeee nee 0020020208680 86
Unclean, gurry @eeeeveeoevoeaeeoeeeeeeevneeeeoeoovaeeoeeeanee2e0 8280800808080
Weight additives @eeeoneeoeseeGeeseeeaeeenevceeeeoeoooeeoenenee 82 e08@
Exterior sand, shell, coral, stone, CUCSeecccoicecclccciciee sce
Interior sand, shell, coral, stone, CtCeccrcccceccccvcccece
Odor S@eeeeeeeeseeeeeeeseoeeoseeeeoeveeoeveosneseeooeosneooeeoeeoeoeee@

Tears @eeeeeeeeoeeeeeseeseeeseeeeooeeeoeeeeseseeeooeoeoeoeeoeoeeoeeeeoeoe
Holes natural, Coo Varce, or throughs ccs cclcleiccc ce ciclc eieisrcle
Holes, crab, baring inside @SCeCeoeeeoeeeeeoeoeeooeaeeoeeoenee02800
Holes, crab, webbed; or uneven DOttom eecccceccccccvccccocs
Holes, natural, from disease @eeeceeoenaeeeoeooooeooaeeeooe0e080
Structure, weak insides @eeeoeeseeoeoeeeseooeoeoeoe00002820808080080208080
Lacking outside webbing Over Noes Wecleiscclecsiccicecicicecicoce
Surface, roller tyDe$ NO Nap ccccccccccccccrercccccscveccs
Surface, inshore type, feathery POCCCOHOHE LC CLOLEELELOOOOO®e
Red bottom or body @eeeeoesoneeoeeeoseeoeoee0eoe22800200888098090808
Feel not springy @eeeeoceseseeeoeoeoooeeseeseoeooeeoeoeeoeoeoeeoe ood
Strength: easily split COHOSHORSSOSSLSHSSHHGHFH2STHOSHSHH8BHSTSHSOSH8HEO
Brittle under pinch and pull SSODSCHSHSHOSSSHSHTSHSGLSOHSHTHBESHSEHO
Low water absorption COOSHOEHLCAET OCHS HSA SOHHHHOHTH SO OOS2OOOS
Wet stiffness: poor cleanability © 000022CTCTHO LAA COOOL E OS®
Wet drainage when tipped COSCHTHOSOOTOOSOSEEOHSOLCOSLOOOOO OOO
Minor faults cocccccccccccccccccccccccccccccccccccescceecesce
Ragged clipping SSHOSHSSHHSHSSHSHSHOFSHSSSSHSHSSHSHOSHSSSHSSSE8SEHSED
Seaweed, CTCeys soft SOTSHSSHSHSHSHOHSHHROTHHHTSCFTHOHSAEHSHHHSHSEHESHHE
Seaweed, etCe, Hard cecceocecceveccoececececscecsececceceoecee

Too flat SOC SHSSSHSSSSEHSZGSSOOGSSHTHSHHFHTLHTE8H9FTEHTH8HTH8S8EFE8OS

as)
E

SO MOAI AAO

Page

Too long SOCHSSHSSSSHSSHESHSSHSSHSHSSHESSTHSHSSHHSSHSSSSSHSSSEHSSSESEEESESEEEE 26
Too tall SCHOSHS HEHEHE HSCEESEHOHESOEHEOEEHEOECOOSESEEESESEEEEEEESE 26
Volcanoes SSOCHSHSSHSHSHSSSHSSSHSSHSSSSHSSESHSHESSHSHTSHHSSHSHESSHEESHSHESEESSEESESESE 26
Side or top valleys or branches SCCCCEOSCHSSESSSOSeEESESELEEEEEESS 26
No bottom webbing S@eeeeeeeSeeeeeeeeoseseeSeeeseoeeeseseseeeeeseeeseee 26
Average number of demerits characteristic of each type and
grade of SPONGES eocccccccccccscccsecsseecsesescecescecscccesed 27
Rock Island COOSEHSCOOOHOSESOSOSOHOOO SESE SO OSO CSE OOS OOES OSES EEEEEOEE 27
Inshore sheepswool SCOOHSHCHSSHHOSOEHSOEOSE SESH EHEOHOEESSOCEESESEOEEE EEE 29
Anclote Grass COOCSCHOOOOCOOH HOHE HOHOOSHSOHSOCOSOOOCE OOOO SO EOOEEOEEEEOSS 30
Florida Key Wool POSES EOEOHOLOHOHEOHOOCOHCHOOHEESESEHOOCOOOEEEHEESOCLESO 30
Hudson Grass SCOHCOHSOHSOHOHOHOSEHOCOSLOLCS SOSH OHS LOOSE E OHO ECEOE OES CEE ECOESS 32
Mediterranean Bengasi Coo ccccccccncccceccccccccccccescecccececence 32
Mediterranean Deepwater CHOCHEOSOHOCOHOS SEE OOSOCE SES ECOOLEEE OOS ECEESEO®D 33
Cuban Sheepswool POHCCOEEOLCOHOSCEEEOLOCOOOCESOO OOO SOLO CES OO OOSCEOESO® 33
Grading standards and prices COCHSHOHOHLHOHSSCEHOHOHOO OOOH SLCEEEOOCOOEOCOSOOO® 35
Quantitative CESLS) cecccceccece ce cece vccciiccecielcisicisieiceicieicicclianicene 37
Water test ccccecccccccccccl ccs csc cl 5l lect eee be cceccece cieicceaeee 37
Bottom can secceccesesceccccecccc cece cc cee clcicisicisicicoceicisiciielclelee 3
Middilic' Canl See ceciccieic cee ccc cece coc cicccicciccics sic cicieicisclcicicisicleleloeatele 38
Top can @eeeeseseessoeoeeeeeeeeseeeeeseeseseeeoeeseeseeoeoeoeoeoeeoeoeeeoeoseeseeee 3
Measuring MOAT “view viccic'c.c 016 ole 016 010 clelcinie oo elclelcicieicleieieleiclelelcioleleictaiatare 39
Procedure used in water tests COHOHSSHSHSOLSSOOSCOHOOCHOLOLOSOSESESES®O 39
Calculation of water properties COSTCO OCEOCOLOCCOSCEOOOOLOLCEECOOEE®
Water=—test conclusionsS ceccoccccccccccccccccccccccccccceccceeee
of water properties COSCCHOHHOSECOS HCOOH SCOOOS EES HEEL OOEOE 5
Field testing PCOHOHCECEOSHSSCOSSEHOCHOHOTOHSOOHOLHO OHO HOCOHO SOHO OEOOOOEO®
Abrasion or Wear Tests eccocccccccccccccccccccccccccececcccce ce ceeee h?
PYOCEAUTE coccccccccccccccccccccccecccccccccecccccecceececeeeee
Abrasion TESULES s:00.0.010.c1c 0100 e.c6icle c.0'e.0/0 oclelclelelelole cleleislelelelcioiciciclelelele hg
Conclusions on abrasion tests SPOOLS EEHOOHSSHOHOHLOHSHOOHOSOCOCEOOOSOO® ho
Cleanliness CEST ccecccccccccccccceccccc cc ccc cc cc sec ceesececceseeee hg
Density test SPCHOHHOHSHHSSHHSHHSHSHHSHSHHHSHSHHSHSHSHSHSHSHSHSHHSHOHSHSHSHSHSSHSHSHSHSSSSHOHSSEHS
Selling by weight SPCHHSHHSHSHSHSHHSHHHHHHHHSHHHSHHHHHSHOHHSHSHHHSHSHSHSSHSSESSEHEOSD 53
Recommendations for grading standards ccccccccccccceccccccccceeecccce

Bibliography SPCHHSSSHSHSHSHOHHSHSHSHHHHHSSHOHSHHHHSSHHSHHSHHHSHSHHSSEHHHSHHHSSSSEHSEOOD

ILLUSTRATIONS
Page

RANTES! Te ——INSHOTE SHEEPSWOO! Ne lcieieicioisicic eisleloicicicievsieieloisjevcieleisieieisisicion (0
RAPUEE! Oo ——tOCk LESTandsONECHSWOO!! ieveleicie cloie aleicve ole c/elelele\clele cleieleje ciel a
Rigure 3.—-Mediterranean Bengasl ceciscscoccccoiocccscoceoccccsss LO
Reopen —— FL OF damNeyaWOO!lW cts elere eleie's ei ciersicieleiele esis eleisieieisieioiee sisiee, (10
Figure 5 .--Cuban Sea Wool @eeeeeeveeenoeovoeeeeeeeeeeaevneeneea een eee eee 0 10
BPP ORO coal VOT asl 1 OW Mss cfelereiele ie eieieleleve eieicicieisie.ele slelelelevsteriolciete! | ae):
ieteurei ic ——ANCTOGCCEGLAGS Melsrelele elclele slelcictelsiclole cleiolels clele’e cloteicielelelcfelelen
erUreE Oe ——=HUdSON: Grass es sicsiclelsiele vieieicls cielcleisiaeleiclelcl ele cielclcicicicsreleieie 1S
Figure 9.--Relationship in the Fall of 1955 between the price

of natural sponges and their size .......ccccesesees 15
APES POs ——WELELESURCGULDMCMb! cicicic sleleciscicclciclccselciceiceciselcc cele If
Eieure sl]. ——Abrasion test EQUIDMENT scccccccccoisccisececccewecee Lt
Pipure 12.—-Natural spongessabrasion LOSS ...c6ccciececiecccsicves DO

TABLES

Table 1.--List of faults and maximum number of demerits given
Por each gOne & cveserevs ciere clots sichelersrctele.c ¢ Selevevele clerevelelsteleiticccen LO
Table 2.--Sheepswool sponges graded by demerits--No. 1 Forms .. 19
Table 3.--Average number of demerits characteristic of each
grade of Rock Island Sheepswool sponge ...ccceccoeese 28
Table 4.--Average number of demerits characteristic of each
grade of Inshore Sheepswool Sponge .cccecececcvccesee 29
Table 5.--Average number of demerits characteristic of each
pradelot Mlorida Yellow ISPDONE Er cele cic sisieievelsteelsisiciciie sce) OO
Table 6.--Average number of demerits characteristic of each
pradesor Anelote GrassMSpONP.e ss isisislelele sleieie/eie)siekeleie.cioie cei oe
Table 7.--Average number of demerits characteristic of each
prade of Florida Key, Wool, Sponge ssisiscisisic cio clsicleieiels ctelen I:
Table 8,--Average number of demerits characteristic of each
grade of Hudson Grass SPONGE) ciecicicicieiecicloieversieltttelereieie ciel OS
Table 9.--Average number of demerits characteristic of each
grade of Mediterranean BengaSi Sponge ..eccccccececes 33
Table 10.--Average number of demerits characteristic of each
grade of Mediterranean Deepwater sponge ...eeccceses 3h
Table 11.--Average number of demerits characteristic of each
pradevofcuban Sea WOO!) SPONGE) c./cicicsiclele oleleiciejcciesielcio OU
Table 12,--Relationship between the diameter of Rock Island
Sheepswool sponges and their approximate weight .... 36
Taplenl j.—=Water=ioldinpe POWEr Giebcc'c leis cle ciciclceviclececisle clcssicieeicte oe
Wap¥or Uy SGUCCZEAUWELNICSS | s.slo cleiciclee ¢ ciciele civic e's cic sleleiesieisicleieleeielonn lS
PADECwI Cl caria Disa LY elelatorelalolelelcietelele cielo oie's elelelevalelelelereleielevelercioiers) (5
WADE Cal am EENESS Mele oles etal olelsiefa cloleloieie e\ele.clcics acie’eie(eleleleiciela er clelen allt
PML CML1o—— MLAS TLCADY: eiciers ste’s ele\c\e's)eielcietielcleleioisieIoieve ei cjevstele’ eieieleterss U5)
FADVEMIOe —=SNIPCATECOVELY, stele cierslols cicleioleleie eislelels wiclele sicleleiesiloievere ea! HO
Table 19,--Results of washing Rock Island Sheepswool sponges .. 52

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INTRODUCTION

According to Contract No. 1-19-008-2378, the work to be
performed by the University of Florida Engineering and Industrial
Experiment Station for the U. S. Bureau of Commercial Fisheries
was the delivery of background information for a grade standard on
natural sponges. In general, the objectives were:

1. To assemble information from which a voluntary Federal
standard of grade and condition of sponges could be developed by
the Bureau of Commercial Fisheries when the need for it had been
demonstrateds

2e To prepare a report on current industrial practices in the
classification of sponges. Sensory tests were to be supplemented by
developed quantitative tests wherever possible.

3e To recommend a sound system of grading based on the above
information, giving ranges and evaluation weights.

These objectives now have been achieved, and the results have
been given in a report on file at the U. S. Bureau of Commercial
Fisheries and at the University of Florida. Since that report is
somewhat voluminous, owing to the fact that it contains most of the
original data that were taken, it has been substantially abridgede
The present report is the result of that abridgment.

References

A selected list of references is given at the end of this reporte
The system of grading proposed here differs markedly from most of
those discussed in these references. Faults that require demerits
in sponges are more numerous than are those in other products reported
in the literature. Fortunately, these faults can be described and
recognized readily--even to degree--by anyone skilled in the tradee

Worthy of special mention is the reference pertaining to fish
sticks (United States Standards for Grades of Frozen Fried Fish
Sticks), since the present work resembles in many respects that on
the grade standards for fish sticks more closely than it does that
on any other standards.

What Sponge Users-Want

For background information, a census was taken of a cross
section of customers in St. Petersburg, Florida as to what they
wanted when they bought a sponge. The census indicated (1) that
the user of sponges is interested in several properties ee in
natural sponges but not present in synthetic ones and (2) that
wearability and ability to hold and release water are of prime im=

portance.

6

Neither of these properties, unfortunately, is covered directly
in the usual grading of sponges, but the graders are aware of their
significance and include many tests that reveal differences influenc=
ing the rate of wear and the action of water in the sponge. The
quantitative tests given in the present report appeared to members of
the Sponge Exchange of Tarpon Springs, Florida, to have possibilities of
satisfactorily measuring these two propertiese

A more detailed discussion of the census that was taken on the
use of sponges is given in a later section in the present reporte

DESCRIPTION OF IMPORTANT SPONGES

The only commercially important sponges in this part of the
world belong to the Keratosa family (De Laubenfels 1953, and Stuart).
Radiating from the base of these sponges, is an interlaced fiber
structure easily seen through a strong lens after the sponge has
been cleaned thoroughly. The fibers are the spongin skeletons of
the many small one-celled animals that make up the sponge. These
cells are capable of individual existence for some time and of
changing in form to assume one of the many duties of a colony of
sponge cells, such as taking in food or throwing off refuse through
separate channels set up for these purposeSe

Most people are familiar with the similar cooperation observed
in a colony of ants or in a hive of bees. The nearest analogy, but
one less familiar, is the colony that forms a coral structure. Here
the skeleton is of hard inflexible mineral matter. Even in sponges,
one encounters some with skeletons containing varying amounts of
minerals similar to sand or limestonee The skeleton of most sponges,
however, is enclosed in a jellylike material that the cells have
secreted and in which they can move. A mineral skeleton also may
have been formed by the cells, starting usually with sharp, pointed
spikes or spicules of mineral matter, which vary widely in shape,
size and amount. The spongin or horn—like animal skeleton, all-
important in the commercial Keratosa sponges, rarely is accompanied
by these mineral spicules. A few other commonly occurring sponges
such as the Loggerhead (not in the Keratosa group) probably would
have been developed commercially, however, if their spicules were
not so hard on the hands during the cleaning of the spongee

The commercially valuable sponges have almost no spicules to
injure the hands, and are given the description "Keratosa, 1-CC"
by De Laubenfels, followed by: "The fibers are solid and opaquee
The dried sponge is still spongy in consistency." (Either of these
usually is adequate for identification.) "It neither emits a strongly
colored exudate, nor a strong, unpleasant odor" when alivee

The "sheepswool" (or wool) type of Keratosa includes Rock Island,
Inshore, Cuban, Florida Key, and Mediterranean sponges, although for

grading purposes, these have to be described separately. This group
has the scientific name of Hippiospongia lachne. When picked, the
Sponges in the group are drab Ss Btack and have a tough, smooth skin
and many connected channels inside. The cleaned wool sponge, if
examined with a strong lens, shows the parallel fibers present in

all the commercial sponges but shows the cross fibers as being smaller,
more abundant, and attached at angles approaching the parallel fibers,
The colors cover the same range as do those of tanned leather, al-
though Occasionally, gray or rusty red variation occur, with the color
being more concentrated in the base of the sponge and practically never
working through to the surfacee Such a red color is considered to be

a fault. A very pale sponge may indicate artificial bleaching, where=
as a very dark sponge usually indicates poor removal of gurrye Such
uneleanliness is detected easily by an unusual stiffness when the
sponge is dry and by a strong odor and milky wash water when the sponge
is wete

Inshore and Rock Island

Inshore-type sheepswool sponges (figure 1) are considered by
scientists to be merely environmentally conditioned variations of the
Rock Island sponge (figure 2). Originally, the tradesmen thought that
the name was appropriate as indicating a relatively sharp division in
the depth of collection; but many are convinced, by overlapping ex=
amples from both types, that the Inshore type is the result of factors
of growth other than depth of watere
Nevertheless, reclassification by
the trade would be difficult to ef=
fect, so the present report did not
eliminate samples of Inshore sponges
when submitted for Rock Island testSe
The tests on Inshores, however, were
made after a few obvious Rock Island
samples had been removed from the
lots tested.

The actual division used by the
trade at present is based almost en=-
tirely on the fact that Rock Island
sponges are collected primarily by
diving boats and that Inshore sponges
are collected primarily by non-diving j ee
or hooker boats, which are smaller }
and collect closer to land with the Figure 1.—Inshore Sheepswool
aid of hooks on long poles.

The Inshore type of sponge differs from the Rock Island type with
intermediate degrees being quite common, by having more large internal
holes and therefore a softer feel; and especially by having, on the
surface, fine tufts or feathers, which often are curled. This feathery

or hairy structure is more common
close to the oscules or openings of
the main channels. The Inshore
Sponges usually are better cleaned
of gurry, but they have a greater
proportion of other faults such as
tears, sand, and minimum surface-
bridging structure. An Inshore
sponge present in a shipment of
Rock Island sponges rarely is
given a number-one grade.

These two types of sponges
differ from the Bengasi (also
spelled Benghazi) Mediterranean
and Deepwater Mediterranean sponges
in that they (1) seldom are flat,
Figure 2e—Rock Island Sheepswool (2) have fewer holes and therefore

more outside webbing or bridging
structure, (3) are darker in color, () are more springy, and (2) re=
gain their shape more readily when wet. As is true of hand tests
with all commercial sponges, such testing should be performed on
freshly soaked and squeezed samplese

Bengasi Mediterranean and Deepwater Mediterranean

Mediterranean sponges are included because they are sold in large
amourts through Tarpon Springs. They differ from the Rock Island and
Inshore types by having practically no surface tufting, and they appear
to have some tufting clipped so that the webbing present is directly
on the surface. When the dry sponge is rubbed on the hand, this sur
face webbing gives a feeling similar to that produced by a rubber
balloon. A skilled inspector, by observing the flatter, paler, yellower,
and more perforated appearance, can detect the Mediterranean sponge at
sight, even when it is dry. Im general, the Mediterranean sponges are
more rounded and are cleaner from gurry than are the American spongéeSe
The color is a paler yellow than is that of the Florida Yellow sponge,
which has an orange tinge and is red-brown inside, and the holes are
more scattered and numerous. The Deepwater sponge, when wet and squeezed
well, is the softest of these sponges, but both of the Mediterranean
sponges are slower to regain their wet shape. This relatively slow
creeping back to shape can be seen by suddenly releasing the wet,
squeezed spongee

The Deepwater type of Mediterranean sponge is the most difficult
to classify as being distinctly different from the Bengasi sponge (fig-
ure 3). The Deepwater sponge resembles the Inshore sponge by being
softer and more porous than is its counterpart. Perhaps careful clip-
ping of the Mediterranean sponges has removed tufts similar to those

present in the Inshore sponges—-tufts
that would make them easier to identify.
The greater softness of the Deepwater
Sponge is not detected easily except
when the sponge is wet. It is puzzling
that the Deepwater Mediterranean sponge
appears to be the softer of the pair,
Since the American Inshore sponge,
which usually is found in relatively
shallow water, is softer than is its
deepwater twin, the Rock Island sponges

Florida Key Wool or Sheepswool

The Florida Key Wool or Sheepswool scree
sponge (figure ) is similar to many Figure 3.--Mediterranean Bengasi
sponges marketed as Inshore spongeSe
It resembles a cross between the Inshore sponge and the Mediterranean
sponge in that it usually has the feathery outside surface: of the Inshore
sponge, but it contains relatively more holes between 1/8 and 1/) inch
in diameter and, in general, is flatter on top. Relatively more of the
Florida Key Wool sponges possess red bottoms and weak inside structures
This description differs from that given by Stuart (Series No. 82),
who seems to have described a poorer type that may have made a slow re=
covery from the Blight of 1939 to 196.

Cuban Sea Wool

The Cuban Sea Wool sponge (figure 5) is another type of Sheepswool
sponge, judging by the samples received. Except for a tendency to be
taller than it is broad, it most nearly resembles the Mediterranean
types in that it contains many holes, has very little surface webbing
or tufts, and is softer than is the Rock Island type.

No differences in the fibrous structures of any of the above wool
sponges could be detected with a good magnifying glass. An examination

Figure h.—Florida Key Wool Figure 5.——-Cuban Sea Wool
10

for spicule types and similar factors as described by De Laubenfels
(1953) might reveal important differences under high magnificationy
but such an examination is not practical for commercial identification.
The differences in wool-type sponges, easily detected by one skilled
in grading, are difficult to describe in terms other than the ones
used abovee

Florida Yellow

The Florida Yellow sponge (figure 6) possesses a reddish-yellow
to reddish=brown color that ranges between the yellow of the Mediter=
ranean sponges and the leather-to-gray color of the Rock Island spongee
The darker red=brown inside is quite characteristic and uniform. The
scientific name is Spongia zimocca or barbara, and it belongs to the
Keratosa order. Ve, is drab to black, with many small holes.
These holes may protrude as volcanoes, which are not large in the
cleaned sponge. The Florida Yellow sponges are much stiffer both
wet and dry, than are other sponges except the Grass sponges. The
Florida Yellow sponge is highly elastic and regains its shape instant—
ly. It has high water-holding power, contrary to popular opinion, but
it does not release water easily, owing to its stiffness. A Yellow
sponge can be distinguished or
easily from a Grass sponge
by tipping the wet and drained
spongee Much extra water will
drain from a Grass sponge be=
cause of its preponderance of
large channels running in one
direction. The Florida Yellow
Sponge, under a lens, resembles
a Grass sponge in that its
parallel fibers are larger than
are the cross fibers; but the
Florida Yellow sponge has a
greater proportion of cross
fibers, and these cross fibers
are not so nearly perpendicular
to the vertical fibers as they
are in the Grass spongeSe

SoS TESS ac ainda sees xe eeereeeene ee
tively stiff, both wet and dry, Figure 6.—Florida Yellow
has a red-brown interior, and
splits fairly easily from the top dow when pulled apart with the
ingens is probably a Florida Yellow sponge. No sponge described by
Stuart (Series No. 82) appears to be this spongee

Any sponge that is rela- ene

Anclote Grass and Hudson Grass

The Anclote Grass sponge (Spongia graminea) (figure 7) is sold
almost always as "cuts," since grows in the shape of a vase, which
is not so much in demand as is the spherical shape. Alive, it is
drab to black, but the cleaned sponge is pale yellow to dark browny

depending on the treatment. These cut slabs, resembling a small=
holed honeycomb, have many large holes and ridges running the length
of the sponge. These, and their extreme stiffness when dry, make
them easily identifiable. Many samples, however, will vary up to
the Eudson Grass sponge (figure 8) in character,

The typical Anclote sponge has
very little outside loose fiber ex-
eept on the top edges; whereas the
typical Hudson Grass sponge (1) is
broader, more hairy all over, and
less ridged and (2) has smaller—
pored interior resembling the Flor
ida Yellow spongee Both grass
sponges, when wet and drained flat
but unsqueezed, pour out much water
when they are tipped to the vertical
position. Grass sponges, under the
lens, show more open structure and
fewer cross fibers, and these cross
fibers are attached more nearly per=
pendicular to the large parallel
main fibers.

The Hudson Grass sponge, which
is relatively new on the market, ap—
pears to be similar both to the
Bahama Yellow sponge and to the Ba=

Figure 7—Anclote Grass hama Velvet sponge described by

Stuart. The Hudson sponge was des=

cribed above as being different from the Anclote Grass sponge. It
might be confused, however, with the Florida Yellow—as well as with
the Anclote—owing to the red-brown interior, but no other sponge on
the market bears the fairly uniform hairy surface. The hairs tend to
concentrate toward the top edge of the sponge, as its variations ap—
proach those of the Anclote Grass sponge. The Hudson Grass sponge
is as stiff as is a Florida Yellow sponge when wet, and it does not
compress as readily on its side as does the Anclote Grass sponge,
owing to the reduced size of the main tubes. In other water tests,
as will be brought out later in the report, it parallels the Anclote

Grass sponge.
The Blight seems to have changed the availability of sponges.

Almost no Wire, Velvet, Reef, or Glove sponges now can be found.
They, however, never were of great industrial importance.

Interestingly, all of the sponges described in this report are
composed of absorbent cages made of fibers, whereas the synthetic
sponges examined were composed of spherical cells that had some
common walls and opened into each other through small holes. These
differences should have a definite effect on some tests and useSe

12

GRADING SYSTEMS

Grading by the demerit system proposed here differs somewhat
from the system of grading presently used by the trade. The following
gives a general description of each system,

Present System of Grading

The techniques now used in the
trade for the inspection of sponges
are entirely qualitative and sensorye
That is, the grader does not add or
subtract numerical values for good or
bad qualities of a particular sponge.
The sensory tests include the use of
sight, feeling and smell.

The sponges are sorted into the
types described in the preceding sec—
tion, dropped sidewise through holes
graduated in steps of one-half inch
to determine the maximum diameters,
sorted into "forms" and "cuts," and
then inspected to determine into which
one of four grades they should be
classified--No. 1, 2, 3, or. A
grade No. 5 has been used, and the
number grades have been subdivided into Figure 8.—Hudson Grass
A's, B's and Specials, but these ad-
ditional subdivisions are reported to be unnecessary complications de—
signed to produce a higher price than that which the sponges ordinarily
would yield.

"Forms" are those sponges that are most perfect, especially in
shape, with a spherical shape being the one most desirede

"Cuts" literally may have been cut from larger sponges, or they
may be sponges that have been distorted in other ways by the clipping
out of a diseased or torn spot or by the irregular growth due to the
presence of another sponge or of a rock, shell, seaweed or crab. A
crab hole is a dished spot or actual hole caused by some form of marine
life. Grass sponges usually are sold as "cuts" because the demand is
low for the vase shape that is the natural pattern of growth of the
Grass spongeSe

; "Rollers" are seen occasionally. If a sponge has grown without
being attached permanently to a rock or similar support, it becomes a
roller with the ocean current. This movement across the bottom of the
ocean causes it to accumulate dirt and to acquire a tough outer skine
Accordingly, it is classified into a much lower gradee

13

Size, as it affects the price (figure 9) of the sponge, does not
follow the expected pattern. Roughly, the price is directly pro=
portional to the diameter rather than to the cube of the diameter as
One would expect if the price were related to the volume of the
sponges (Volume equal Ri divided by 6 and mltiplied by the cube of
the diameter o-- V = °/ Except for display purposes, most sponges
more than 8 inches in diameter sell slowly and, accordingly, are cut
into sizes that are easier to hold. The work of cutting and trimming
and the loss of material incurred just about offset the value of the
extra volume in a larger sponge.

The curvature and the slope of the lines in figure 9 will be
affected by changes in the supply and demand for different sizes at
different times.

Until quite recently, many sponges were sold on the basis of
weight. Sale by size now is recommended by the members of the Sponge
Exchange, and measurement of the perimeter of the sponge is preferred
over measurement of the maximum diameter used by many, as well as
over the three-diameter method suggested here. Details on the above
points will be discussed later in this report.

Demerit System of Grading

The details of inspection by the demerit system have been placed
under proper headings in the following section on Discussion of Faults
but an overall picture of the method of grading is described at this
point.

Except for work in the Sponge Exchange or in packing houses,
most of the inspections take place after a shipped bale or box of
sponges has been opened. These sponges are found to be highly com=
pressed and should be sampled according to section F of Federal
Specification C-S-63lb for "Sponges; Natural," which is in Part 5
of Section IV of the Federal Standard Stock Catalog.

The sponges should be wet and squeezed thoroughly before being
inspected. The perimeters should be measured according to the Federal
specifications or, if the agreement requires, should be checked for
size by a "go — no go" test by means of standard boards with circular
holes decreasing in diameter in steps of one-half inch. The three
diameter test described later under Miscellaneous Studies may merit
consideration, however, since it (1) gives more data than do the "go -
no go" boards, (2) is quicker than are perimeter tests, (3) gives one
number that approximates the "go — no go" tests, and (h) causes no
arguments as to whether the perimeter tape was poorly placed, was too
loose, or was too tighte

It might be worthwhile also to specify a minimm rate of sampling
for lots of different size in the manner specified on page 5 and

PRICE IN DOLLARS

ROCK ISLAND SHEEPSWOOL
ROCK ISLAND SHEEPSWOOL
ROCK ISLAND SHEEPSWOOL
ROCK ISLAND SHEEPSWOOL
ROCK ISLAND SHEEPSWOOL
ROCK ISLAND SHEEPSWOOL
ROCK ISLAND SHEEPSWOOL
MEDITERRANEAN BENGAST

MEDITERRANEAN BENGASI

A
B
C
D
E
F
G
H
I

MAXIMUM DIAMETER OF SPONGE IN INCHES

Figure 9.--Relationship in the fall of 1955 between the price of
natural sponges and their size.

15

section 52.38 in the reference on processed fruits and vegetablese
Other suggestions for changes in Federal Specifications are dis=
cussed later,

Grading for demerits usually proceeds as follows for the indi-
vidual, thoroughly wet and squeezed sponge:

1. Check for trueness to type according to the "Description of
Important Species," given earlier. Any lot containing sponges not
true to type should be rejected as being impossible to grade. Such
lots should not be encountered, however, since an experienced seller
would not make this mistake.

2e Check the sample for size according to a mtually accepted
standard method. It is suggested that not more than one-sixth of
the samples fails to meet the size indicated—to borrow the phrasing
common in Agriculture Standards. An adjustment in price could be
made if this requirement as to size is not met.
3- Look for faults:
ae Smell the sponge for strong odor.
De Squeeze out a few drops of water to detect gurrye
Ce With both thumbs first placed on top of the sponge, run
them dowm the sides at several spots and look for holes
and other faults.
de Inspect the bottom for dirt, holes, and looseness.

ée Use the thumb and forefinger for squeezing to detect
interior dirt, such as shells and rocks.

£. Squeeze the whole sponge in one or two hands to detect
elasticity, stiffness, poor recovery of shape, or weak
inside structuree

Ze Inspect surface structure and shape closely.

h. Test for brittleness and tendency to split.

i. Run any special tests for a particular type or usee

lh. Assign demerits to the sponge according to the agreed standard
system of demerits.

5. Determine the grade of the sponges in the lot by considering
the average number of demerits that were assigned to the sponges in
the given lote

DISCUSSION OF FAULTS

As was indicated in the preceding section, the individual sponge
is given demerits for each fault that is found by inspection. The
maximum number of demerits given depends on the seriousness of the
fault. This maximum number ranges from 50 to 300.

The faults are divided into two groups: major and minor. Major
faults are those requiring a maximum of 200 to 300 demerits. Minor
faults are those requiring a maximum of 50 to 150 demerits. Both
the major and minor faults, in turn, are divided into two sub-groups:
workmanship and character. Faults included under workmanship are
those controllable by the seller. Those included under character are
controllable only by selection and gradinge

A list of the faults and the maximum number of demerits suggested
for each are shown in table 1. A typical example indicating how many
demerits would be assigned in actual practice to one lot of sponges
of a particular type and grade is shown in table 2. The following
gives a discussion of each fault.

Major Faults

A. Bleached.-—-To determine the color of a bleached sponge, one
could use an accepted publication of color standards for reference,
but customers are not interested particularly in the attractiveness
added by bleaching. Evidently, sellers are aware of this fact and
also of the fact that all known methods of bleaching are reported to
weaken the sponge, since very few domestic sponges received were
definitely bleached. The few that were given demerits for being
bleached could have been affected by variations in growth or by ex=-
posure to sun, which seems to have been the case for the Mediterranean
sponges that were inspectede Bleaching may be partially the cause of
certain of the accompanying poorer qualities in these sponges. At
present, the only advice that can be given on grading this fault is
to say that familiarity with the usual color will make possible the
detection of any excessive amount of bleachinge

Be Unclean, gurrye-—Uncleanliness is indicated by excessive
stiffness in the dry sponge, which almost invariably is accompanied

by a color that is darker than usual and by a clinging together of
the finer outside fibers. The Rock Island sponges were found to be
the least cleaned of gurry (residual dried oxidized flesh). Such
sponges, when wet, often will evolve a fishy smell, feel sticky, give
a milky discoloration to the first wash, and leave a smear on clean
glass. On thorough washing, no sponge should lose more than 10 per-
cent of its weight figured on the dry basis.

This test gives additional evidence that the sale of sponges

should be made on the basis of size rather than of weight. Practi-
cally all sponges now are being offered for sale on a size basisy

a,

Table 1.—list of faults and the maximum number of demerits

given for each one

Faults

Be Unclean, gurry
Ce. Weight additives
De Exterior sand, shell, coral, stone
Ee Interior sand, shell, coral, stone
F. Odor
Character

e lears
He Holes, natural, too large or through
I. Holes, "crab," baring inside
Je Holes, "crab," webbed, or uneven bottom
Ke Holes, natural, small, from disease
L. Structure weak inside
M. Lacking outside webbing over holes
N. Surface, roller type, no nap
O. Surface, inshore type feathery
P. Red bottom or body
Qe Feel: not springy
Re Strength: easily split
S. Brittle under pinch or pull
T. Low water absorption
U. Wet stiffness: poor cleanability
Ve. Wet drainage when tipped

Minor

Workmanshi
Ky Ragged clipping

Be Seaweed, etce, soft

C. Seaweed, etc., hard

Character

D. Too flat

Ee Too long

Fe. Too tall (e.g. vertical cuts)
G. Volcanoes

H. Side or top valleys or branches

No bottom webbing

18

emerits
given each fault

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[oomadeoys—°z ctqel

_although they still can be bought on a weight basis, as they have
been for many years. In the past, the problem of gurry in sponges
has been a serious one for the industry. A specification as to
cleanliness therefore is recommended to prevent this problem from
recurringe

Ce Weight additivese—When sponges were sold on the basis of
weight, gurry and dirt sometimes were left in the sponge intention-
ally. Weight additives also were worked into the sponge. A specifi=
cation for uncleanliness will deter any tendency for the industry to
slip back into these uneconomic practices, which work against its
welfare under competitive conditions,

Although each seller of sponges who "loaded" them had his own
formila, in every case known, the weight additive could be washed
out with water. This fault therefore merely requires an extra 200
demerits to be added to Fault B if evidence of loading is founde

Weight additives fall into two classes: water soluble and water
insoluble. The water-soluble type would be suspected if the sponge
lost a lot of weight on being washed but did not develop a foul odor
(due to gurry) when wet and kept in a closed container for 2h hourse
The water-insoluble type, usually needing the first type to make it
adhere to the sponge, would be fine sand, barytes, whiting, lith—
arge, or similar insoluble material, which easily can be detected by
an examination of the first wash water for insoluble fine powder.

Sale on the basis of size rather than weight, however, gives no in=
centive to load a sponge or to leave in more than 10 percent of gurrye

D. Exterior sand, shell, coral, stone, etce-—-Inspection of the
bottom ot the sponge usually will reveal most of the exterior dirte
Complete removal of dirt is difficult and time consuming without de=-
stroying some of the bottom webbing, which is one of the stronger
parts of the sponge. Very little if any such dirt should be tolerated,
however, in the present market, which is so keenly competitive. Syn=-
thetic sponges never contain dirt, and Mediterranean sponges are al=
most as clean. Obviously, very few uses of sponges will tolerate harsh
particles. Even a small amount of dirt therefore justifies large de=
merits if the inspector finds that the dirt is easy to remove without

injuring the sponge.

Several people in the trade have recommended that sponges be
clipped from their roots. If the root is left to grow a new sponges
production is increased, and very little bottom dirt is collected;
but the new sponge tends to grow in a flatter shape, which results
in few forms, and the strong bottom webbing is lost. The advantages
of clipping the sponges from their roots appear to outweigh the dis=
advantages, however, if one realizes that the value of the spherical
form is questionable in view of the competition with the synthetic

sponges

Ee Interior sand, shell, coral, stone, etce—When dirt such as
sand and shell w e icv. © remove without injuring the sponges

20

the sponge cleaner is confronted with a difficult decision. He may
have to make cuts from a good forn, downgrade the sponge because of
the cut, or run the risk of having the sponge downgraded or rejected
by the buyers

Large particles can be detected by pinching the whole wet sponge
at different spots, whereas small particles—usually sand——can be
detected by close visual inspection through the channelse Some sponges,
especially those of the Grass and the Inshore types, tend to incor=
porate small particles of sand and shell during their growth. Mediter—
ranean sponges, likewise, sometimes appear to grow around particles
or stone. These small objects are almost impossible to remove and,
accordingly, might be considered to be a character fault instead of one
of workmanship. In either case, however, the demerits for these faults
should be majore

Fe Odore—Odor invariably will accompany poor removal of gurry
if the wet Sponge is kept in a closed container for 2) hourse At
that time, the sometimes mild fishy odor develops into a strong one
resembling ammonia. It obviously lowers the value of the sponge to
the consumer. Customarily, however, demerits are assigned only on
the basis of the odor of the freshly wet sponge. Such practice was
followed by the writer in his studies of gradinge It should be kept
in mind, however, that a gurried sponge that has been dried rapidly
in the sun may develop little odor when it is freshly wetted.

G Tearse—The first major fault of character in the list given
earlier considers any definite separation of the main body—not the
surface fibers--to be a tear, whether it be caused in collecting, in
removing an embedded shell, or in too drastic cleaning--such as
running the sponge through wringing rolls. Tears show up quite readi=
ly during the initial handling by the inspector. The wet sponge is
held in both hands, with thumbs on top of the sponge, and the thumbs
are allowed to slide, with pressure, down the sides of the spongee
Repeated on two to five diameters, this procedure will reveal the
tears. This same riffling, with the roots up, will reveal the bottom
imperfections, including dirt and crab holes. Serious tears rarely
appear in the marketed sponges, since torn spots are removed before
the sponges are solde

He Holes, natural, too large, or throughe—-The writer has
graded the -apongas -ueoon@ing to the, caster of eiving large demerits
if the channels run through to the bottoms so daylight can be seen
through them. Actually, the thin bottom webbing that saved many
other sponges from receiving such large demerits probably does not
give much longer life to the sponge. Holes larger in diameter than
1/2-inch should be given demerits in proportion to the diameter of
the holes and to the number of them. Such holes tend to form weak
spots from which tears eventually will start during the useful life
of the sponge. It is difficult to set up a numerical proportion be=
tween demerits and the number or size of holes, but each hole larger
in diameter than 1/2-inch should be given 50 demerits, or more, de=
pending on the size.

21

I. Holes, crab, baring insides—Final users will agree with
the writer's division of crab-hole grading to assign slightly more
demerits to a hole that is unlined by protective tissue. Crab holes
are made by many forms of life other than crabs. The result, howevey
is the same. The hole may appear anywhere——on the surface or in the
interior. Surface grooves usually wear a protective coating or
webbing similar to the usual bottom structure and, as such, are
covered in Fault J, but sometimes an interior hole—usually starting
close to the bottom and rarely penetrating the top—bares the inside
structure and is not protected by webbing. Such defects should be
given demerits as large as those for tears. They usually drop the
rating of the sponge by one grades

Je Holes, crab, webbed; or uneven bottome—Since the effect
is the same with uneven bottoms as with webbed holes, these faults
have been combined, whether they be due to webbed crab holes, to
another sponge growing closely nearby, or to a stone or shell on which
the sponge was growing. The resultant distortion, if large enough,
May cause a Form to be graded as a Cute

K. Holes, natural, from diseasee—The writer was alarmed to
find af er sponges contained areas of sleazy or thin
growth, since these might indicate the persistence of blights, even
though they were being kept under control. Such a spot, or its
trimmed place, would justify demerits somewhat more than would a lack
of webbing over a corresponding area (see M)e

L., Structure, weak insides.-=Softness is another fault that is
difficult to evaluate. A soft sponge, as tested by pinching or
Squeezing the whole wet sponge, may be attractive at first to the
majority of customers, but this fault usually indicates that less
material is present ’and that accordingly, a shorter life is to be
expected. It should therefore receive demerits. On the other hand,
the Grass sponge and the Florida Yellow sponge usually are too stiff
for ready acceptance except for special uses. The greater proportion
of water that can be removed from a Hudson Grass sponge than from an
Anclote sponge (see Cleanability, under the quantitative tests) be-
cause of an apparently weaker inside structure, conceivably could be
considered as being an advantage. For purposes of inspection, a
squeeze of the sponge with the full hand will reveal any definitely
weak inside structure. If demerits have been made for excessive holes,
the mumber of additional demerits for weak structure has to be deter=
mined by closer visual inspection for loose fine structuree

M. Lacking outside webbing over holese—=Although the useful life
of a sponge 1s mich greater than 1S the time elapsed in wearing through
the outside fiber and webbing that form the surface of the sponge,
this webbing probably constitutes a resistant layer that reduces tear=
ing during its existence. A reduction in the amount of this webbing

22

therefore should receive demerits. The initial riffling by the in-
spector to uncover holes and tears will reveal the percentage of sur=
face webbing. (Bottom webbing is covered under I in Major Faults.)

Ne Surface, roller type; no nape—Rollers rarely are encounter—
ed in the trade, owing either to the fact that they are considered
practically worthless or to the possibility that the conditions that
caused them have improved. One reported source is a sponge that is
lost by the collector before it has been exposed to air long enough
to be killed. The dropped sponge continues to live, but it rolls with
the currents on the floor of the ocean and acquires the characteristic
lack of surface fibers and equally characteristic bottom structure over
the entire sponge. The presence of this bottom structure is a minor
item, as it can be argued that such a sponge should bring a premium,
owing to its greater resistance to weare It should be given a fault
rating, however, to prevent the uninformed buyer from being sold an
item that is reputedly off grade.

O. Surface, inshore e, featherye—Feathery structure is an=
other cass OPS SF SpSE Ee Tet sau be etivactive to come buyerse The
Hudson Grass sponge sometimes brings a higher price than does an An-
clote sponge, owing to a feathery or hairy structure. This structure
makes a softer sponge of a type of sponge that usually is too stiff.

An arbitrary plus 50 points therefore are given to a typical Hudson
Grass sponge for this property. (Note: In the system of grading rec—
ommended in this report, to give plus 50 points is actually to subtract
50 demerits.) On the other hand, the Inshore Sheepswool type is most
easily distinguished from the Rock Island type by means of this feath=
ery structure, which often is accompanied by other less desirable
properties. Points can be taken off in proportion to the percentage

of surface covered by such feathery structure and to the length of such
fibers, which may reach1/2 inch. The feathers may wear away rapidly
and therefore deserve demerits aside from other accompanying undesir=—
able propertiese

P. Red bottom or we wear tests had proved to be more
significant, was p ed to check one possible reason for the down=
grading of sponges that appear to have been discolored by a deposi-
tion of iron oxides. No consistent trend to poor properties, however,
appeared to accompany such discoloration. Rock Island sponges rarely
are so colored. The discoloration therefore, at one time, may have
served as a quick check as to type. In the author's examinations,
Florida Yellow sponges were quite consistent in the degree of such
redness and accordingly received a uniform demerit of 100 points.
Using this standard color and demerit as a guide, the inspector can
estimate the degree of discolorationy with 200 demerits as a maximum
to be applied. As in A, the use of a scientific color designation
would depend on a balance of the cost of the research needed to de=
velop the designation versus the benefit to be derivede

23

Qe Feel, not spri e—According to the apparent judgment of the
trade rather than being eS on the accompanying quantitative tests
for elasticity, this fault was set up to cover apparent hardness or
stiffness that prevents an inspector from compressing the sponge to
any large extent. By strict definition, the fault should be labeled
"low compressibility," but the word "springy" conveys more to the
average person. To reduce the number offaults, the author used this
term to cover low visual snap back due to hardness or stiffness and
also to cover the other occasional lack of snap back or springiness
encountered in relatively soft sponges that appear to be soggy. This
deadness is encountered occasionally in sponges that have been dried
at too high a temperature or that have been squeezed too drastically
in the cleaning step. The Florida Yellow sponges have received de-
merits due to their uniformly hard character, and an occasional sponge
of the other types has received some demerits for being soggy.

Re Strength: easily split:—If the riffling step is modified
by first pressing the sponge tightly before the hands are rotated, a
splitting force is exerted that will tear open some sponges. The
Grass and Florida Yellow sponges often show this fault, but more often
it is accompanied by a lack of surface webbing in any spongee A lack
of bottom webbing allows the sponge to be split easily from the bottom.
Several noncommercial sponges may owe their lack of development to
this fault. Judgement as to the proper relative rating can be ob-
tained only through experiences

Se Brittle under pinch and pulle—Grass, Florida Yellow, and
highly bleached sponges often Tail under the test for brittleness,
which involves pinching a small tuft between fingernails of thumb
and forefinger followed by pulling and twisting to break off a portion.
Again, experience cannot be put into numerical description. Such
brittleness would be expected to be accompanied by poor wearing quali-
tiese

Te Low water absorptione—If no quantitative tests are used,
the rating given this Fonte of low absorption of water indicates the
inspector's opinion as to the relative value of a particular type of
sponge, since the property of water absorption is one of the most im
portant to the ultimate user of the sponge. Briefly, it consists of
an estimate of the relative weight of water that can be picked up by
the sponge on the first wetting. The writer suggests that this be
the first subjective test to be replaced by a quantitative onee

U. Wet stiffness: oor cleanabilitye—In looking for prop=
erties that would justify the low prices Breuent by the Grass and the
Florida Yellow sponges, the writer decided that wet stiffness was
one of the very important properties. Quantitative tests reported
later in this report verified this conclusion. The inspector judges
this property by the relative amount of water that can be squeezed

2h

out of the sponge. The amount of water absorbed and the amount
Squeezed out both are judged by gentle swinging of the sponge up

and down to feel the weight. The term "wet stiffness" is not used in
the trade, and the use of it therefore may not be desirable; but it
does describe accurately the property that causes poor cleanability,
or difficulty in squeezing out the water that has been absorbede A
porous brick may absorb as much water for its size as a sponge does,
but it would be a worthless substitute, owing to the fact that water
cannot be replaced by squeezing and rewettinge

Ve Wet drainage when tippede-—-An easy test of identity for Grass
sponges can be run by thoroughly soaking the sponge, laying it gently
to drain on its flattest side without tipping, then tipping it by
lifting it by the top tufts. From a third to a half of the water will
pour out of the Anclote and Hudson Grass sponges in less than a minutee
In general, Anclote sponges will drain faster than will Hudson spongese
For most uses, this property would be a disadvantage, so demerits are
given for ite In sponges used for cleaning with other solvents, how-
ever, this property could be an advantage. It would enable such a
sponge to be rinsed out readily without hand squeezing, for example,
which would be a convenient property when some solvent such as gasoline
is used to clean greasy motors. A quick quantitative test could be
set up to rate sponges according to this property, but it was thought
to be of minor importance at this time. A qualitative hand test, hom
ever, is as easily evaluated as are the tests for absorption and clean—
abilitye

Minor Faults

Ae Ragged clippinge—Only occasionally does the inspector en=
counter sharp corners left in sponges by poor clipping. Nothing but

the appearance is improved by smoother contours, however, so very few
demerits are justified for this defect. It is notable that Mediterran=
ean sponges are more carefully contoured than are the domestie spongese
Failure to remove a tear by not making cuts from a form, may justify
all 50 demerits.

Be Seaweed, etce, soft.e—Since it takes time to remove the last
traces of soft seaweed often found inbedded in the sponge and since
complete removal may be difficult without ruining the sponge, very
few demerits are justified for this defect. Furthermore, the soft ma-
terial soon washes out during use and causes no harm to the surfaces
being washede.

Ce Seaweed, etce, harde—-A more serious inclusion of woody
growths that might scratch surfaces deserves a greater number of de-
merits. More than 100 points would be justified except that almost
invariably, such particles are noticed the first time the sponge is
Squeezed and are easily pulled out.

25

De Too flate—Flatness and associated faults are considered to
be important only from the standpoint of appearance unless the irreg=
ularities in shape are so extreme as to cause breakage of the sponge
in usée Since these shape faults are the most important in classi-
fying the sponge as a Cut rather than as a more valuable Form (other
than an obvious product of cutting), they may have been relatively
more important in the past trade than what the writer has allowed
in the present demerit system, but the data accumlated in this study
do not justify larger demerits. As a rough guide to the inspector,
any sponge less than half as high as its radius in the horizontal
plane would receive close to 150 demerits.

Ee Too long.—As distinguished from Fault D, a sponge can be
narrow—-or too [ong—as well as being too flat. If one horizontal
diameter is more than twice the other, afull 50 points should be
deductede

Fe Too talle—-Cuts made in the plane vertical to the base or
root of the sponge—this being the usual method of cutting—-often
cause a sponge to be tall enough to be unattractive. Grass sponges
are almost invariably cut this way, owing to the fact that the orig-
inal form is vase-shaped and awkward to usee Some Cuban Wool sponges
appear to grow quite tall. A full 100 points should be taken off for
heights more than twice the length of the longest horizontal diametere

Ge Volcanoese—Almost all types of sponges show a variation
occasionally toward projecting tissue around the channels or osculese
The trade appears to downgrade such sponges fairly severely, and
therefore it is surprising that the projections are not trimmed.
Volcanoes usually are accompanied by a weak structure, but they re=
ceive demerits here merely because of poor appearance. Volcanoes
more than 1/2 inch high would receive a full 100 demerits, since
they rarely occur with single holese

He Side or top valleys or branchese——Except in the Grass and
the Florida Yellow sponges, side or top valleys or branches usually
are trimmed awaye Projections greater than an inch should receive a
full 150 demerits if the valleys are quite sharp, since breakage
occurs easily at these lines.

Ie No ee eel for eventual acceptance of
sponges cut to leave the bottoms to grow again, the fault of no
bottom webbing does not receive mich downgrading in the tradee lack
of bottom webbing, however, can cause a quick breakup of the sponge
in use. If it were not for advocating the leaving of the root to
grow again, the writer would recommend a more drastic penalty than
100 demerits for a complete lack of bottom webbinge

26

AVERAGE NUMBER OF DEMERITS CHARACTERISTIC OF EACH TYPE
AND GRADE OF SPONGE

When the system of demerit grading described in the preceding
section is applied to sponges, the average number of demerits assigned
to a lot varies both according to the type of sponge and to the grade
of spongee With Rock Island Sheepswool sponges, for example, No. 1
Forms will average 50 demerits and Noe 3 Forms will average 125 de-
meritse On the other hand, with Mediterranean Deepwater sponges,

No. 1 Forms will average 350 demerits and No. 3 Forms will average
630 demerits. Thus, the average number of demerits varies according
to both the type and the grade of sponge under consideration.

In practice, we find that the number of demerits assigned to an
individual sponge varies widely from the average for its type and pur—
ported grade. The question naturally arises as to what is a reason=
able variations It is suggested that a good basis of judgment would
be to consider the magnitude of the variation in relationship to the
midpoint between the average number of demerits characteristic of the
purported grade and the average number characteristic of the next gradee

The fact that the number of demerits assigned to a particular
sponge deviates widely from the average for its grade shows the need
for careful sampling in the grading of spongese

In the event that the demerits assigned to individual sponges in
a lot are found to deviate too widely from the average for the pur—
ported grade of the lot, there are two possible solutions to the prob=
lem: (1) regrade the individual sponges or (2) assign a different
grade to the lot as a whole. In either case, the basis for reassign=
ment of grade could be the midpoint between the average number of de-
Merits characteristic of the purported grade and the average number
characteristic of the next gradee

It thus becomes important, in the demerit system of grading,
accurately to determine the average number of demerits characteristic
for each type and grade of sponge and the midpoints between these
characteristic mumberse

Accordingly, the various types of sponges were graded by the
demerit system in order that the characteristic number of demerits
for each type and grade could be determined. The results are reported
in the following subsections.

Rock Island

Table 3 gives the average number of demerits characteristic of
each grade of Rock Island Sheepswool sponge. Inasmuch as the number
of demerits found by actual grading will fluctuate, depending on the
lot of sponges and upon the grader, this number is subject to some
variation. Accordingly, since round numbers are more convenient

ai

to use, the numbers determined by grading were rounded off and ration=
alized to give the figures shown in the colum headed "Demerits rec=
ommended to be taken as characteristic."

Table 3.--Average number of demerits characteristic of
each grade of Rock Island Sheepswool sponge

Average demerits Demerits recom- {Recommended mid=-
Grade found by grading | mended to be taken| point to next
as characteristic| lower grade

Forms Number
No. 1 75
No. 2 260
No. 3 55
Cuts
No. 1 105
No. 2 300
No. 3 565
Forms and Cuts
No. 765

The following notes were taken during the determination of the
values given in table 3.

1. Some faults seldom occur in Rock Island sponges, and the num
ber of demerits rarely approaches the maximum number that is assign=
ablee To omit these infrequently occuring faults or to lower the
maximum assignable number of demerits, however, might encourage the
offering of sponges inferior in these points in the belief that the
points are not important. It is therefore recommended that the faults
and the mumber of demerits be retained as listed in table le Buyers
are reminded thereby of faults not present in the sponges and accord—
ingly have greater appreciation of the sponges of high quality.

2, A feathery outside structure or "Inshore" type of surface
often is accompanied by dirt and weak inside structure.

3. Gurry usually is accompanied by odor. The number of demerits
for this fault seems consistently to be higher for sponges from some
suppliers than from others.

hh. A number of suppliers preferred to submit mixtures, such as
"mixed 1 and 2 Cuts," but these were regraded for the purpose of the
present work. Sponges of grade No. h, however, are believed logically
to be kept as "mixed Forms and Cuts,"

28

5 The point spread between grades increases rapidly. Thus the
desire to allow more tolerance for poorer grades is satisfied.

6. Holes are the most common fault in No. 1 and No. 2 Forms. The
Same observation applies to Cuts, with the expected increase in number
of demerits being found for poor shape. Lack of outside webbing is a
common fault in No. 1 and No. 2 Forms. Weak structure is a common
fault in Noe 3 sponges. No. lh sponges show an increased trend toward
tears and the "inshore" type of surfacese

Inshore Sheepswool

Table )} gives the average number of demerits that is characteristic
for each grade of Inshore Sheepswool sponge. As compared with Rock
Island sponges, the Inshore sponges showed more demerits for inside
dirt, weaker structure, feathery surface, and lack of surface webbinge
Less gurry was found, and the cuts did not seem to earn as many de=
merits for poor shape.e Tears, when present, appeared to be relative—
ly worse, probably because of the method of harvestingse

Table ),--Average number of demerits characteristic of each

grade oO nsnore eepswoo sponge

Average demerits Demerits recom— |Recommended mid-=
Grade found by grading | mended to be taken} point to next
as characteristic] lower grade
Number
Forms
No. 1 Ws5
No. 2 BBD
No. 3 580
Cuts
No. 1 190
Noe 2 370
No. 3 590
Forms and Cuts
No. 780

Table 5 gives the average number of demerits that is character—
istic for each grade of Florida Yellow sponge. Distortions were rare
in this sponge. The principal faults encountered were large natural

29

holes, tears, and exterior dirt. This sponge was found to be more
uniform than was any other in the following three characteristics:
red body, ease of splitting, and stiffness when wet. These character=
istics can be used for purposes of identification. A standard number
of demerits for each one was given to every Florida Yellow sponge.

Table 5.—-Average number of demerits characteristic of each

grade oO orida Yellow sponge

Recommended mid=
point to next
lower grade

Average demerits} Demerits recom
found by grading | mended to be taken
as characteristic

Number

Forms

No. 1 525

No. 2 630

No. 3 770
Cuts

No. lL Su5

No. 2 650

No. 3 780
Forms and Cuts

No. Not available 880

Anclote Grass

Table 6 gives the demerits found for the Anclote Grass spongee
Forms were practically nonexistent. This sponge almost always con
tained some trapped sand or shell particles, was quite tall and ir-
regular in shape, had poor tear strength, contained many large holes,
and when not too stiff to be squeezed easily, had a weak inside
structure. No new faults became prominent as the grades went downe

Florida Key Wool

Table 7 gives the presently available data on the average number
of demerits characteristic of the Florida Key Wool sponge. Not enough
samples were received to give a firm average grade rating at this
time. Since this sponge showed evidence of Inshore feathers and re=
sembled a cross between Inshore sponges and Mediterranean sponges,
ratings for Inshore sponges were used tentatively as a guide. The

30

Table 6.—-Average number of demerits characteristic of each
grade 0 clote Grass sponge

Recommended mid=
point to next
lower grade

Average demerits | Demerits recom
found by grading | mended to be taken
as characteristic

Grade

Number Number
Cuts
No. l Not available 680
No. 2 690 755
No. 3 808 865
\ 912

Table 7~—Average number of demerits characteristic of each

grade oO orida Key Wool sponge

Recommended mid=
point to next
lower grade

Average demerits| Demerits recom
found by grading | mended to be taken
as characteristic

Number Number
Forms
No. 1 Not available 170
No. 2 255 355
No. 3 575
Cuts
No. Not <ineeats aoe
3 3
hho 585

655

samples of the Florida Key Wool sponge had a relatively weak inside
structure, lacked a fair amount of surface webbing, had a relatively
large number of holes 1/8 to 1/4 inch in diameter, and tended to be
flatter on top than is the typical sheepswool spongee Many of the
Florida Key Wool sponges split easily.

31

Hudson Grass

Table 8 gives the number of demerits that is characteristic of
each grade of Hudson Grass sponge. This sponge shows variations ap=
proaching the Anclote sponge. It also approaches the Florida Yellow
sponge in inside dense structure, but the outside invariably is soft
because of the presence of 1/ inch or mow of bridged fibers that
vary from individual curly hairs to branched tufts resembling featherse
These tufts are more highly branched or less clumped than are those of
Inshore sponges. When wet, the Hudson Grass sponge is stiffer under
light pressure than is the Anclote sponge, but it is softer than is the
Anclote sponge under heavy pressure. In this property, it resembles
the Florida Yellow sponge. It generally is thicker than is the same
width of an Anclote sponge, and it has been given a plus credit for the
soft outside structure as compared with that of the Anclote sponge.

The Hudson Grass sponge tends to hold mich sand and shell in the lower
grades, often is torn, is split fairly easily, tends to be brittle,
drains out a fair amount of water on being tipped, and shows more holes
as the grades go down.

Table 8.—Average number of demerits characteristic of each
grade 0 son Grass sponge

Recommended mid=
point to next
lower grade

Average demerits] Demerits recom
found by grading | mended to be taken
as characteristic

Number Number
Cuts
No. 1 636 655
No. 2 672 ThS
h Not available

Mediterranean Bengasi

Table 9 gives the number of demerits that is characteristic for
each grade of Mediterranean Bengasi sponge. As compared with the Rock
Island sponge, the Mediterranean Bengasi sponge, in general, was paler,
was more rounded, was flatter, held more water per unit volume, was
less compressible, was less elastic, was more readily split, recovered
its shape more slowly after being pressed, contained more small holes,
contained less surface webbing, and had more discoloration. No new
fault became particularly prominent as the grades went downe

32

Table 9.—Average number of demerits characteristic of each
grade erranean Bengasi sponge

Average demerits | Demerits recom Recommended mid=
found by grading | mended to be taken | point to next
as characteristic lower grade

Mediterranean Deepwater

Table 10 gives the average number of demerits characteristic of
each grade of Mediterranean Deepwater spongee This sponge was similar
in most properties to the Bengasi Mediterranean sponge. The Deep=
water sponge held less water, however, and was much softer when wete
It therefore released more water and was easier to clean. It was less
elastic and regained its shape more slowly, and had a weaker inside
structure because of greater porositye

Cuban Sheepswool

The Cuban Sheepswool or Sea Wool sponges inspected were a mix=
ture of Cuts, and no Forms were present. In fact, most of the samples
were too tall to be classified as forms. Only one Noe lh Cut, however,
was in the lot, and most of the samples were No. 2.Cuts. The samples
gave off some odor, were low in outside webbing, and had many small
holese Recommendations as to the number of demerits were influenced
by the numbers assigned to the Mediterranean sponges, which the Cuban
Sheepswool sponge resembles. Except for No. 2 Cuts, which were avail-
able for inspection in quantity, the numbers of demerits shown in
table 11 is tentative, since they require the inspection of larger
samples for confirmatione

33

Table 10.--Average number of demerits characteristic of each
grade = Mediterranean Deepwater sponge

Average demerits

found by grading

Recommended mid=
point to next
lower grade

Demerits recom
mended to be taken
as characteristic

Number

Forms

No. 1 hho

No. 2 580

No. 3 675
Cuts

No. 1 645

No. 2 755

No. 3 8L5

Forms and Cuts
No.

Table 11.--Average number of demerits characteristic of each

grade of Cuban Sheepswool sponge

Recommended mid=
point to next
lower grade

Average demerits | Demerits recom
found by grading | mended to be taken
as characteristic

Grade

Number Number
Forms
No. 1 Not available 375
No. 2 Not available 525
No. 3 Not available 750
Cuts
No. 1 66 505
No. 2 55h 650

Forms and Cuts

No. 925

L/ Except for No. 2 cuts, these figures are tentative because they re=
guire larger samples for confirmatione

3h

GRADING STANDARDS AND PRICES

A study of sponge prices during the fall of 1955 showed that the
increase in price with size followed a fairly straight line for each
type and grade of sponge, as is idealized in figure 9 on page 15.
Since a sponge contains marketable material proportional to its vole
ume, it might be expected that the price would increase as the third
power of the diameter. There was a slight upward curvature with in=
creased diameter for some grades, but in general, it appeared that
larger sizes must be increasingly difficult to sell, for the sponges
were sold proportional to the first power of the diameter rather than
to the third power. The relationship between the weight of the Rock
Island Sheepswool sponge—-expressed as the number of sponges per pound
--and the diameter of the sponge is given in table 12,

If it were not for the cost of the labor, it would appear to be
advantageous to make Cuts of the larger sizes, since the smallest
size--l\-1/2 to 5 inches-=-appears to bring a premium price. Although
the demand may be larger for the small sponges, the trade hesitates
to handle them because collection or possession of any uncleaned sponge
less than 5 inches in diameter is illegal. Fear has been expressed
that it may not be generally known that there is appreciable shrinkage
between the size of the live sponge and the size of the resulting
cleaned spongeée

Using the.slope of the lines obtained as in figure 9, one finds
that each type and grade of sponge bears a definite ratio by price
to the other sponges of corresponding sizee For instance, Florida
Yellow No. 1 Forms sell at about half the price of the corresponding
Rock Island Sheepswool spongee

When a particular grade of sponge is in short supply, there is
a tendency to broaden the grading range by including grades both above
and below. The average value--in this case, the average number of
demerits—is still close, however, to the previous one. This ten-
dency is entirely different from the one shown when all sponges were
searce during the last war, which was to raise prices and to lower
gradese The present system of demerits, employing dimensionless units
as it does, would forestall such a trende

35

Table 12,.—Relationship between the diameter of Rock Island
Sheepswool sponges and their approximate wei ght

Diameter of sponge Weight of sponge

% Except for shrinkage effects, forms would not appearo

36

QUANTITATIVE TESTS

Four quantitative tests are discussed in this section: water
test, abrasion test, cleanliness test, and density teste

Water Test

The following water properties of sponges were quantitatively
determined:

le Kin

20 K

water-holding power

squeezed wetness

sw ened)? x
3. K, - cleanability a
he K, - stiffness

Se K, = elasticity
K

6. K,, - shape recovery

These properties are express-
ed by mathematical symbols--K.,,K,,
and so on—because all are calcu-
lated values that are computed from
measurements made on the spongee
These measurements were as follows:

V - Bulk volume of sponge.
Wy - Volume of water absorbede
Wpi- Volume of water absorbed

after sponge has been
tippede

Figure 10.—Wet test equipment.
Wy - Volume of water remaining
after sponge has been pressede

Height of uncompressed sponge.

a
I J

Height of compressed spongee

A
q

Height immediately after pressure is releasede

Height 2 minutes after pressure is releasede

J
i

The device used for obtaining these measurements is shown in

figure 10. This device consists of three concentric cans supported,
One above the other, by a framework of three pipes welded together in
such a manner as to form a triangular tower )|-1/2 feet high. A pulley
device is attached to the top of the tower for raising and lowering
the top cane

37

Bottom cane-——-The bottom can, approximately 12 inches in diameter
by 13 inches high, is essentially a reservoir for holding a measured
volume of water. Connected to the bottom of the can is a pipe. By
Means of rubber tubing, this pipe leads to a piece of glass tubing that
is held by clips on to a support fastened firmly to the can and that is
used as a gauge to determine changes in the volume of water contained
in the cane

In figure 10, this glass tubing is shown protruding at an angle
from the lower right side of the picture. This tube will indicate a
change of 60 cubic inches in the volume of water. It slopes upward
with a rise of 1 inch in 10 horizontal inches, which slope permits a
sensitive reading of any change in the volume. The midpoint of the
tube corresponds to a height of water in the can of about 9 incheSe

A scale for determining changes in the volume of water in the
can is made from a small strip of soft copper. The ends of the strip
are cut and bent into clips so that the scale can be hung on the glass
tube and moved along as desired. Four calibrated reference lines are
scratched onto the scalee Additional lines are added and so spaced
that the scale covers 60 cubic inches and indicates major divisions
at each cubic inch of volume change in the main tank.

Vibrations retard the reading of the gauge. The stand therefore
must be braced well and the tank bearing the gauge mist be fastened
firmly to a heavy table. A small level is attached to the arm that
holds the gauge so any displacement of the gauge may be correctede

Middle cane—The middle can is essentially a metal measuring
basket. It is li inches high and 10-1/2 inches in diameter. Serving
as the bottom is a heavy, Tlmineh thick iron plate, which has holes
bored in concentric circles, the radii of which differ consecutively
in length by 1/2-inch.

The basket contains two vertical slots cut into the opposite
sides in a sawtooth pattern with a tooth for every half inch of heighte
By sighting across the teeth, one can estimate the height of a sponge
placed in the baskete

Welded onto the side of the basket near the top are three small
lugs. These lugs fit into slots cut into the upright supporting pipes
and permit the basket to travel up and down without rotating. The
upper ends of the slots are cut and widened in such a manner that by
a slight twist of the basket, the lugs have a support that enables the
basket to be held suspended in place in a "rest" positione

Top can.e—The top can is essentially a vessel for exerting pres=
sure On a sponge held in the middle can. This top can is 1) inches
high and of such a diameter as to fit closely inside the middle cane
A loose handle is attached inside the top rim. The can is lifted up
and down by means of rope and pulleys attached to the top of the sup-
porting frame. The pressure exerted is variable by means of the
amount of water or number of weights placed in the cane

38

Measuring boarde—In addition to the device described above, a
measuring board was used for determining the size of the sponges. This
board, which is shown in the lower left hand corner of figure 10, con
sists of two boards, each of which is one foot square and is nailed at
right angles to the other. In addition, a vertical strip of aluminum
is nailed to the front of the base. The aluminum strip bears a half=
inch scale; the back vertical board bears horizontal lines marked in
divisions of one-half inch; and the bottom board bears concentric cir=
cles one-half inch apart. All scales are suitably numberede

Procedure used in water tests.—-The following procedure is used
in the water tests:

1. Fill the bottom tan with water until the level in the slant-
ing glass tube reaches the midpoint.

2e Blow gently into the end of the glass tube several times to
prevent any clinging of the water to the glass and resulting inaccuracy
in the determination of the level of water.

3. If difficulty is encountered in determining the level, poke
a few grains of surface-active material, such as Dreft, into the tube
with a wiree

he Immerse the middle can, or measuring basket, in the water in
the bottom can to wet the measuring baskete

5. lift the basket out of the water up to the rest position and
allow any water present to drain from the baskete

6- Move the copper scale to indicate the starting level of water
in the cane

7e Place a sponge in the basket and immerse the basket and sponge
in the watere

8. Press the sponge against the bottom of the basket with a smooth
rod (not had) until no more bubbles of air rise from the sponges

9. lift the basket from the water to the rest position and let
the free water drain back into the bottom cane

10. Read the copper gauge to determine the volume of water absorbed
by the sponge and record this volume as Wh, the water holding power.

1l. If the sponge is a Grass sponge, tip it on end, lean it against
the side of the basket to drain, and record the resulting final volume
as Wht for the Grass spongee

12. Press the sponge well to remove water, and transfer the sponge
to the measuring boarde

13. Read the smallest and largest diameters of the sponge by means
of the circles on the bottom of the board.

39

lj. Read the height of the sponge by means of the half-inch marks
on the vertical strip of aluminum and the horizontal lines marked on
the vertical back board.

15. Record the height of the sponge as Hs, the height of the un-
compressed spongee

16. Multiply the smallest diameter by the largest diameter and
then by 0.4; that is, Ds; x D, x O.4. (Note: The answer gives the weight
in pounds needed to apply a pressure of 1/2-pound per square inch to
the sponge.)

172 Multiply the answer obtained in step 16 by the height of the

sponge and then by 1.33 that is (Dy xD. x Och) x Hy x 1.36 (Notet
the product obtained is approximately equal towD3 .)
nome

18. Record the answer obtained in step 17 as being V, the bulk
volume of the spongee

19. Subtract the weight of the top can or pressure vessel from
the answer obtained in step 16,

20- Add to the pressure vessel a weight in pounds equal to the
answer obtained in step 19.

21. Place the sponge in the measuring baskete

22. Lower the measuring basket into the water, submerge the sponge,
and press out all the bubbles again.

23~ Raise the measuring basket to the rest position.
2he Slowly lower the pressure vessel onto the spongee

25. Determine the volume of water remaining in the sponge by
reading the copper gaugee

26. Record the answer obtained in step 25 as being Wr, the water
remaining in a sponge when a pressure of 1/2—pound per square inch is
applied.

27- Observe the height of the sponge and record the height as
being He, the compressed heighte

28. Quickly raise the pressure vessel from the sponge and im-
mediately observe the height of the sponge.

29. Record this height at being Hpre
30. Wait 2 minutes and again observe the heighte

31. Record this height as being Hos the height corresponding to
the permanent sete

Ie)

Calculation of water properties.—The data obtained by the pro~
cedure described above were used to calculate the following quantita=

tive values:

A. Water-holding power. This gives the volume of water absorbed
as a percentage of the bulk volume of the sponge. Water-holding power
is the volume of the sponge divided into 100 times the volume of water
absorbed: Ky = 100 W/V

Be Squeezed wetness. This gives the water remaining after pressing
as a percentage of the bulk volume of the sponge. Squeezed wetness is
the volume of the sponge divided into 100 times the volume of water re=
maining in the sponge after the sponge has been subjected to a pressure
of 1/2-pound per square inch: Kgwe 100 Wr

Ce Cleanability. This gives the ability of theuser to remove the
dirty water from the sponge as a percentage of the water left in the
sponge after pressing. It is the volume of water left in the
sponge divided into 100 times the volume of water squeezed out of it:

Ky = 100 (WH - Wr) /W,

D. Stiffness. This gives the difficulty in compressing the sponge
as a percentage of the height of the uncompressed sponge. Stiffness is
this height divided into 100 times the new height during compressing:

Ks = 100 H,/Hs

Ee Elasticity. This gives the ability of the sponge to return
immediately to its original shape as a percentage of the height of the
uncompressed sponge. Elasticity is this height divided into 100 times
the immediate height after the pressure is released: Ke m= 100 Hy/Hs

Fe Shape recovery. This gives the ability of the sponge to re=
turn, 2 minutes after the pressure on the sponge is released, to its
original shape as a percentage of the height of the uncompressed spongee
Shape recovery is this height divided into 100 times the height 2 min=
utes after the pressure is released: Koy m= 100 Hp/Hs

Water-test conclusions.e—-Standard statistical techniques (Snedecor
196) were used in arriving at the conclusions that follow on the water
testSe

A. Water—Holding power, as shown by table 13, is least for the
Anclote Grass and the Hudson Grass sponges. Although the average for
the Hudson Grass sponge is higher than is that for the Anclote Grass
sponge, the fidicial limits for these two overlap. A superiority there-
fore cannot be claimed for the Hudson Grass sponge on the basis of the

resent size of samplese_/
1/Mathematical statistics are based on probability and the larger

the number of observations, the greater is our confidence in our con=
clusions and the narrower we can set our fiducial limits. We might point
out, however, that the mathematics are such that to narrow appreciably

the fiducial limits reported here would require much larger samples, ~
which would greatly increase the cost of the tests without adding pro-
portionately to additional knowledgee

Tal

The same is true for the next distinctly more superior group. More
tests, for instance, might show some significant difference between
Florida Yellow, Inshore, Mediterranean Deepwater, and Rock Island
Sponges, but with the present data from a relatively limited number
of samples, the only conclusions are that in water-holding powsr,
these sponges overlap in individuals even though they are all supe-
rior to the Grass sponges. Mediterranean Bengasi sponges, with the
highest values, within 95 percent statistical probability, definitely
hold more water per unit volume than do the Inshore, Deepwater, and
Rock Island sponges, but the Bengasi sponges cannot be said to be
more absorbent than are the Florida Yellow sponges. This test, in it=
self, is not too important. A brick made with the proper pore size,
for instance, theoretically can hold more water per unit volume than
can amy sponges

Table 13.—-Water-holding power

Fiducial
limits2

Number of
sponges tested

Type of sponge

Average Sieneaa

Slt
8.5
Tel
720
99
206
hed

Percent
5164-5508
yo eli=5 206
13.92-h9 02
4302-86
39 9-17 06
3607-388
34.05=38 6

Mediterranean Bengasi

Florida Yellow

Inshore Sheepswool

Mediterranean Deepwater

Rock Island Sheepswool

Hudson Grass

Anclote Grass

U/ this column shows the variability in water-holding power among
sponges of a given type. The large-the number in this colum, the
greater the variability in water-holding power.

2/ this column indicates the limits within which the averages of
the samples will fall 95 times out of 100. With ig coer ode
gasi sponges, for example, the average water-holding power wi e
expected to fall between 51. and 55.8 percent in 95 out of 100
samples of 25 sponges eache

42

Be. Squeezed wetness, the next test to be considered in the order
of testing, shows (table 1) that with 1/2-pound per square inch pres—
sure, the Florida Yellow sponge releases the least water. No distinc=
tion can be made statistically among the other types of sponges testede

Table 1).--Squeezed wetness

Type of sponge

Florida Yellow
25 b= 3705
280-3367
2827-3320
25 00-3705
2606-3007
25 05—29 08

Anclote Grass

Rock Island Sheepswool
Hudson Grass
Mediterranean Bengasi

Inshore Sheepswool

Mediterranean Deepwater

Ce Cleanability is the practical result of the two preceding testSe
Inshore and the Deepwater Mediterranean sponges, owing to their combined
absorbency and softness,can be washed out faster with the same amount
of squeezing than can any of the other sponges. The statistical anal-
ysis (table 15) shows that Rock Island and Mediterranean Bengasi sponges

Table 15.—Cle anability

| Number of Average | Standard
ponges tested

Type of sponge

Mediterranean Deepwater 60 eh-7667
Inshore Sheepswool 5302-719
Rock Island Sheepswool | 39 06-5605
Mediterranean Bengasi hhel-h9 »

Hudson Grass 1720-293
Florida Yellow 1605-268

11.3=20 3

Anclote Grass

are not as high in this test as are the Mediterranean Deepwater sponges,
but with the number of samples run, there was no significant difference
between the Inshore and Rock Island sponges. The Inshore, Rock Island,
and Mediterranean sponges, however, have a higher cleanability than
have the remaining three. These three--Hudson Grass, Florida Yellow,
and Anclote Grass=-give practically the same low value of cleanability.
Again, it must be remembered that other factors enter into the choice
of a spongee Grass sponges, for instance, drain out a lot more water
When tipped on end. This property would apparently make them easier

to clean, but the same modification of the test would work against them
in water-holding power. The drained water would drastically reduce the
maximum amount of water that they could be said to holde

De Stiffness tests (table 16) indicate that there are three groups
statistically different from each othere The Mediterranean Deepwater
are the least stiff (in other words, the softest), followed closely by
a tight group camposed of Inshore, Rock Island, and Mediterranean Ben=
gasie Bridging the gap, but not distinctly different from the stiffest
group, is the Anclote Grass spongee The Florida Yellow and the Hudson
Grass sponges are the other stiff sponges.

Table 16.--Stiffness

Type of sponge

Zhe 27 02
3607-1506
2605-37 07
21e -256

Hudson Grass

Florida Yellow
Anclote Grass
Mediterranean Bengasi
19 5-22.43
19 .5-2167
149-18

Rock Island Sheepswool
Inshore Sheepswool

Mediterranean Deepwater

E. Elasticity is important. Whether the sponge be stiff or soft,
the user wants it to regain most of its shape immediately. Under the
carefully controlled conditions of these tests, both soft and stiff
sponges can be said to have the same elasticity with the exception of
both of the Mediterranean sponges (table 17); for instance, Inshore,
Rock Island, Florida Yellow, and Anclote Grass sponges all have the same
high elasticity. Only the Hudson sponges recover more of their heighs
immediately. The Mediterranean Deepwater sponges are the least elas-
tic, with the Bengasi having a definite superiority over the Deepwater
sponges. Hlasticity may be an important property in determining the
preference for the domestic sponges by several of the trade groups,
such as window washerSe

hy

Table 17.--Elasticity

Type of sponge Number of Average
sponges tested

Hudson Grass
Inshore Sheepswool 8004-965
94.096.
93 4-963

75 05-9603

Florida Yellow
Anclote Grass
Mediterranean Bengasi
Rock Island Sheepswool

Mediterranean Deepwater

F. Shape-recovery testing allows the sponge 2 minutes to recover
its original size. If the sponge does not spring back immediately on
repeated fast squeezing during washing, however, this slow spring=—
back does not mean that a few minutes of soaking will still leave it
without good recovery of shape. Nor does a slow return at the end of
2 minutes mean that the sponge has become "dead" or “not springy."
None of the sponges are really poor in this respect at the end of 2
minutes, and it was observed that with repeated wettings, the slow
shape recovery of the Mediterranean Deepwater sponges (table 18) is
not progressive or ever permanent. This test cannot therefore be
called a "permanent set" test in the scientific meaning of the wordse
By accidentally drying some sponges at too high a temperature and
also by squeezing sponges through steel rolls at high pressure, the
author obtained sponges that were "deade" In short, they took such
a high permanent set that they resembled a wet cloth and were practi-
cally worthless. Aside from the Deepwater Mediterranean, all the
sponges had a high recovery of shape in 2 minutes.

of water propertiese—A summary of water properties does
not Seal any one outstanding type of natural sponge, but these quan=
titative tests (the first ever published) should enable a buyer to pick
the type of sponge he needs for a particular property. These tests
agree well with the sensory tests that have been used for many years,
in these particulars:

1. The choice of natural sponges for commercialization is veri-
fied in that all show useful properties. No one sponge is superior
in enough properties to justify the exclusion of others from the tradee

2. The softness of the Mediterranean Deepwater sponges and the
stiffness of the Grass and Florida Yellow sponges are confirmede

45

Table 18.—Shape recovery

Type of sponge

Hudson Grass

Anclote Grass 97 1-99 02
87 2-99 »2
97 02- 98.5
9103- 98.5
9001— 960k

75 e2- 83-0

Mediterranean Bengasi
Florida Yellow

Rock Island Sheepswool
Inshore Sheepswool

Mediterranean Deepwater

3e The difficulty in cleaning the Grass and the Florida Yellow
sponges is confirmed.

lh. The low absorbency of the Grass sponges is confirmed. The
high absorbency of the Bengasi sponges, however, was not known, or
at least not publicized in the domestic trade. It is interesting
that the Florida Yellow sponges, however, are statistically not any
less absorbent.

5- The low elasticity and shape recovery of the Mediterranean
Deepwater sponge, with the Mediterranean Bengasi sponge being close
behind in elasticity, are shown.

6. The high shape recovery of the Hudson Grass sponge, with the
Anclote Grass, Florida Yellow, and Rock Island sponges in the next
close group, also is shown.

Field testing.—-Originally, it was hoped that a simple field
tester could be devised to make use of the important quantitative
findings based on wet testing, as described above. If in the future,
this test still is thought to be important, it is suggested that a
first trial could be made by using a type of pliers that would bear
two porous plates and a standardized spring. The spring could be set
in notches corresponding to a definite pressure per square inch for
the average diameter (in other words, area) of the sponge, and the
spring could be cocked with the plier handles. The procedure in
this test could be as follows: (1) The sponge is wet in a standard
volume of water in a calibrated vessel and placed between the plates.
(2) The volume of water is observed in the vessel. (3) The spring
is released so that the sponge returns water to the vessel under a
standard pressure per square inch exerted by the spring. And (})

The volume of water in the vessel is read again. A table would allow

6

reading without any calculation of the resulting absorptivity and
squeezed wetness. Stiffness and shape recovery could be calculated
from heights observed at the same time, but the technique required
might be too demanding for the results obtained. Even the reading
of the volumes in the vessel might require a training program.

Abrasion or Wear Tests

The equipment used in the abrasion tests was based on a Paint
Washability and Abrasion Machine, Model Number 105, obtainable through
the Gardner Laboratory, Bethesda, Md. This machine (figure 11) is
capable of recording — ae
the number of times :
it rubs a sample across
a standard surface ei-
ther with or without
the presence of a liq-
uid. It was designed
to rub a standard sponge
or abrasive block a-
cross a painted surface
until the paint shows
Signs of wear, thereby
allowing the comparison sats sein omeeaeenen
of paints under standard Figure 11.—Abrasion test equipmen
conditions. The appara-
tus and operations were modified for use with sponges by:

be

nett,

1. Using a standard sheet of wet-dry silicon carbide paper
(Tri-M-ite, OOA grit) instead of a painted surface, and changing it
after each set of sponges had been tested. Reuse of the paper gave
poor resultse

2e Shortening the stroke of the machine to 10 inches so that
it did not run off the ends of the standard-size silicon carbide
paper (83 x 11 inches).

3. Tilting the machine a few degrees so that water could be run
across the abrasive surface at the rate of about one cubic centimeter
every 5 seconds.

he Holding the silicon carbide paper tightly against the bottom
of the pan with a metal plate bearing rubbing slots so that the paper
did not move and wrinkle.

5. Modifying the frame, which holds two samples at a time, so
that the boxes that hold the blocks bearing the sponges are held loose—
ly in the frame. This modification allows the sample to be pushed
rather than pulled, thereby reducing the tendency of the front of the
sponge sample to dip and dig into the paper. If the sponge is allowed

7

to dip and dig, the front edge of itwears off rapidly. The frame
furnished with the equipment was attached to the sample boxes as in
tended by the manufacturer, but around this frame was placed a Formica
rectangle that received the pull from wires leading to a reciprocating
arm. This rectangle extended over the edges of the water pan upon
which it slid in slots cut in the Formica. Wet Formica has a very low
coefficient of friction. Since the rectangle could not dip and since
it pushed the frame carrying the sample boxes at a point below the usual
center of rotation at which they dipped before the change in design was
made, the dipping was practically eliminated. Accordingly, the sponge
samples wore evenly.

6. The samples were wired front and back to zinc diecast blocks,
which originally were the blocks bearing the bristles intended to scrab
paint samples.

7e The amount of wet sponge extending below the edge of each box
varied with the softness of the sponge, in spite of the fact that all
sponges were cut wet to 13" x 14" x 34" standard sizee In a few cases,
extra soft sponges still allowed the box to hit the abrasive paper be=
fore the test was finished. In these cases, strips of plastic were in-
serted behind the sponge holder in the box. This insertion of plastie
Was particularly necessary when a soft sample was being tested along
side of a stiff sample.

8. Standardizing on sponge samples cut from the top surface so
that the samples were representative of the sponge but did not contain
amy large holes. The samples were tested with the surface against the
emery paper and usually were tested with one sample from one sponge
and with the other sample from another sponge, so that any large dif=
ferences between different sponges could be detected. The number of
strokes varied from 500 to 1500. The machine ran at 60 strokes per
minute. By means of weights in a pan attached to the top of the frame
fastened to the sample boxes, the pressure on the sample could be
varied. The initial pressure of 0.22 pounds per square inch was not
changed, since all the experimenter's time was spent in trying to get
more accurate data. The sponges travelled over a path of 10 inches
and were 35" long, which left an actual rubbing path of 63 inches, or
a total travel over paper, in 1000 strokes, of ne feet—-or more than
a tenth of a mile.

Procedure.—The data were obtained as follows: The wet sponge
was cut as described above, dried at 1)00-1600F., weighed warm to
offset the rapid absorption of moisture from the air (a Rock Island
sponge, when exposed to 100 percent humidity, picked up 1 percent
moisture), rewet, wired to the block, abraded, and redried along with
any large pieces of sponge that may have been torn off during the teste
The wear was calculated to a standard 1000 strokes for comparison.

148

Abrasion resultse—-The data are given in figure 12. In this
figure, the length of the line represents the spread of values that
are characteristic of the given sponge, within the probability chosen
for statistical analysis. Since the data were not as accurate as were
those for the water tests, an 80 percent probability limit was chosen.
In other words, there is only one chance in five that any average
sponge of the particular grade chosen will give abrasion losses out-
side of the range depicted by the line on figure 12 for that spongee
The maximum loss of any sample tested was less than 2 grams from a
sponge sample weighing ).l) grams. Most of the sponges showed a loss
of less than 1 gram.

Conclusions on abrasion testse-—-More work is needed to correlate
the abrasion test with types and grades of sponges. Although there
are some trends in the data, this test cannot presently be used to
predict sponge wear in actual services

The main trend appearing in the data is for the relatively stiff
sponges--Florida Yellow, pale Anclote, and pale Hudson—to give the
least abrasion loss, and for the loose-structured sponges—-Inshore,
Deepwater Mediterranean, dark Hudson, and dark Anclote--to give the
most abrasion loss. So few Florida Key andCuban Sea Wool sponges
were available that no conclusions can be drawn regarding them ex—
cept to say that neither gives high abrasion losses. Aside from the
relation to variations in bulk density (stiffness and looseness), it
appears that the fine structure of all of these sponges has about the
same rate of weare

The test does not reveal a consistent progression from No. 1
through No. lh grades of spongese The explanation for this fact is
that the distinctions between grade numbers have been on the basis
of faults that would not have much effect in a small sample. Further=
more, Forms differ from Cuts mainly in shape, which difference also
would not become evident in the small samples used in this teste
Thus, a more realistic wear test should be based on using the whole
sponge, rather than on using 14" x 13" x 33" samples, so that such
defects as large holes and weak inside structure would have more
chance to affect the results of the wear test. Bulk density also
is worthy of investigation.

Cleanliness Test

On the basis of studies reported in table 19 (page 57), it is
felt that no natural sponge should contain more than 10 percent of ma-
terial that can be removed by thorough washing. Since the determina-
tion of the amount of material removable by washing requires the use
of an analytical balance, in most cases a qualitative test may have to
be substituted. The following is suggested: Dampen the sponge with
a minimum of water and do not rinse. Squeeze out a few drops onto a
piece of glass. Reject the sponge as unclean if the drops appear to
be milky against a dark background, or if on drying, the plate shows

h9

Figure 12.--Natural sponges abrasion loss, statistically
reliable within 60 percent probability.
Type of sponge Grams lost*

Rock Island . Tobe 2.000
Sheepswool 1 Form ——
Ay
3 F =
LF & Cut =.
1 Cut
2¢ —_——
5)
Inshore Sheepswool} 1 F =
2F _
3F a Pan Par OPP Gk ENS
LF
ES (6 —
3¢ ae RE
Florida Yellow 1F —=
2F —_
3} 18 ——=
1C ==
2c —
3¢ =
Anclote Grass, 2c Se
Dark 3C —_
kc re
Anclote Grass, ab (0; =
Pale 2c —>
3¢ =
Hudson Grass, ac ae
Dark 2c rape Sie
3¢ =
Hudson Grass, 1c —
Pale 27°C ==
Mediterranean, ably —
Bengasi 2F =—
(or Hard) 3F ——
KF&C =
Ab (o3
2c
3 ¢
Mediterranean,
Deepwater

(or Soft)

WNHr FWNHEH
aqgaQgaqary yyy
&

Q

ON
is3]
|

Florida Key Wool

E —

ON

Cuban Sheepswool

* Per 5.25 square inch for a 0.22 pound per square inch load over 542 foot
path on wet 400 A silicon carbide paper.

50

the presence of a film that is appreciably greater than that left

by the pure water. The water squeezed from the sponge should not

leave a sticky feeling on the fingers, nor should there be any ap=
preciable smell.

Density Test

The density of the spongin or structural material of sponges
was difficult to determine. No matter how finely the samples were
divided, they tended still to hold sand particles, which increased
their weight, or to hold bubbles, which decreased their weight. Best
results were obtained by cutting the sponge into thin slivers, pound=
ing and rolling the slivers between a glass rod and plate in water
containing Dreft until the sand was washed out, bringing a Dreft solu=
tion suspension of sponge material to a boil (with constant prodding)
to remove air bubbles, cooling and examining with a good lens to deter=
mine whether further cleaning was needed. The sponge material should
not be allowed to drain out any water until the density is determined
by displacement in the customary specific-gravity bottles, or the boil=
ing operation will have to be repeated to remove air bubbles. The
best tests indicated that the basic material of these sponges had a
density of 1.50 grams per cubic centimeter of sponge material.

A more convenient figure, and one that does show some differ=—
ence between types of sponges and individual sponges, is that of
the bulk density. This value is the weight of the sponge converted
to grams per cubic centimeter or pounds per cubic foot for the bulk
of the sponge. Where cellulose sponges have been manufactured with
an unusually low bulk density of 3.26 pounds per cubic foot, and a
urethane type sponge possessed a bulk density of 2.60 pounds per
cubic foot, the natural sponges treated were of even lower bulk dens—
ity of about 2 pounds per cubic foot. Not enough figures were ob-
tained to report reliable average values for other than the Rock Island

spongee

51

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52

SELLING BY WEIGHT

Federal Specifications contain information relative to two peri-
meters of the sponge and relative to the weight of the sponge, either
of which information could be used as a basis for the sale of sponges.
In the past, sales ordinarily have been made on the basis of weight.
Recently, many people in the industry have felt that sales should be
on some other basis. The members of the Svonge Exchange, for example,
recommend using perimeters (rather than "go-no go! holes} and the
writer recommends a simple three-diameter measuremente

The need for the change is well known. In the past, up to 100 per—
cent weight has been added by foreign materials, which not only were
troublesome to put into the sponge but had to be removed from it before
it could be sold to the ultimate consumer. No one in the trade was mis-
lead by this practice. It was merely a nuisance. Today even with the
practice perhaps permanently discontinued, natural sponges still are
being offered in an unattractive form that favors the sale of compet—
itive materials in that varying amounts of gurry are left in to increase
the weight, which unfortunately results in unpleasant odor, unattrac-
tive appearance, and undesirable feel.

The seller caught in the change over to cleaner sponges is faced
with the problem of convincing the buyer that these cleaner--and there-
fore lighter-—-sponges should sell for more even though they weigh lessSe
Sales by volume or dimensions is the answer. The increased value then
is obvious, since the sponges are more pleasing in appearance when well
washed. Table 19 gives data illustrating the kind of analysis that
would enable the buyer further to recognize the enhanced value of the
well-cleaned spongee The data in table 19 show that the first lot of
unwashed sponges contained, on the average, 36 to 8 percent of "gurry,"
on a dry basis. The second lot of sponges, which was representative
of the new voluntary standard, contained only 6.8 percent, on the aver=
agee These data indicate that a 10 percent content of material that
can be washed out is a reasonable maximum limit.

Another factor that makes dimensions a better criterion than weight
as a basis for sales is the fact that a sponge that has been dried picks
up moisture rapidly from the air after it has been removed from the
driere Experiments showed that Rock Island sponges soon picked up more
than hO percent of their weight when dried and then put beside a beaker
of water in a closed vessel. Under ordinary conditions, these parti-
cular sponges contained from 9.5 to 53.5 percent moisture. The latter
figure was obtained on the specially washed samples and therefore in-
dicates that the hygroscopic property of the gurry is not the only
factor causing the sponges to absorb water from the air. Obviously,
sale by weight is inaccurate, since the content of moisture may marked-
ly vary from a dry to a damp day or as a result of the moisture that
has been purposely addede

The method of determining diameters recommended by the writer

requires only an easily constructed measuring: boarde (This board was
described under water testing.) The sponge, which has been moistened

53

to permit examination for grading, is laid on its broadest side in

the center of concentric circles scribed on the base board, the maxi=-
mm and minimumdiameters are noted, and the center height is sighted
between the backboard scale and the front half-inch-marked poste A
single figure that gives the approximate volume of the sponge can be
obtained by dividing the product of the three diameters by two.l/ This
method of measurement is faster than is the determination of perimeters
with a tape measure, gives one figure instead of two, comes close to
the true volume, and avoids inept placing of the tape or pulling it too
tightly or too loosely. A wet sponge is easily distorted.

Utne volume of a sphere is equal to D3. The coefficent 1
to zelemnich is approximately equal to 1/2 or 0.5. Since the sponge

is not truly spherical, the figure 0.5 is close enough to the true value
of 0.52.

RECOMMENDATIONS FOR GRADING STANDARDS

The following is a report of a meeting of the Sponge Exchange,
held on November 8, 1955 at Tarpon Springs, Florida:

1. Each part of the present "Federal Specification for Spongesy
Natural" under the number C-S-63lb, June 2), 19))1 of the Federal Stan-
dard Stock Catalog, Section IV, Part 5, as well as Amendments 1 and 2,
was discussed and agreement reached as to recommendation for retain-
ment or modification thereof.

2e On several occasions it was brought out that the members of
the Exchange felt’ that the most important recommendation they wished
to make was:

Wherever foreign natural sponges are compared with domestic natu-
ral sponges both groups should be treated in exactly the same manner.
For instance, in C-S—63lb, Paragraph B-1 labeled "Tyne", Type I and
Type XII and Type XIII are considered by some purchasing agents to be
approximately equivalent and are so indicated on requests for bids.
Since Type XII and Type XIII include both forms and cuts, mixed, while
Type I allows only forms to be considered and since cuts are usually
accepted as being lower priced than forms, Type I (the domestic) sponges
have been unjustly penalized. Obviously "mixed" must be defined as
50-50, etc., for similar reasonse

It was recommended that Type I should, therefore, include cuts
and that "mixed" should be defined. In fact, this may have been the
original intention of the Specifications since Rock Island sheepswool
middle range cuts No. 1 are not listed under any type although both
cuts and forms are listed for No. 2 quality. This change should be
made as soon as possible.

5h

SiR It was recommended that the term "middle range" be droppede
This term has no definite meaning in fathoms, it is impossible to certi-
fy and is an unnecessary limitation, since some sponges in this approxi-
mate 4-9 fathom area are not sufficiently firm, while some sponges from
other depths often are of as good or better qualitye In other words,
sponges are graded now by more significant qualities than the areas from
which they are taken. The acceptance of the new term "inshore type"
eliminates the need for the exclusive term "middle range,"

h. Much discussion took place as to the significance of "Rock
Island" and other area designations. Although it was agreed that grad—
ing is done now by more significant quality designations than by areas,
it was felt that the term "Rock Island Sheepswool" has become an un=
official trademark of a desireable type of sponge and should be retained
in entirety.

5. The "inshore type," mentioned above was recommended for in=
clusion in the grading standards. In general this is a type found at
all depths and easily recognized by its shagginess and looser structures
This is believed to be due to a faster rate of growth, which is common
to but not limited to areas near the mouths of streams.

6. Also discussed were the Cuban natural sponges. Until more
than one type of these become commercially available and significant,
a more specific designation cannot be made than that under

Type Xetalets

ite Also recommended, in view of the admitted difficulties encoun-
tered in writing a non-controversial description of grading, is the hiring
by the Government of men competent in grading. A Government employee in
Tarpon Springs to certify shipments would be the simplest solution.

8. After mich discussion of the complications involved in carry=
ing out this last recommendation, the members of the Exchange listened
to Dr. Bennett's description of the scientific tests that he was making
and decided that these should answer the purpose. Dr. Bennett reminded
them that such tests of absorption, cleanliness, abrasion resistance,
resiliency, etce, would have to be accompanied by some descriptive
matter, might have to be run in a reasonably equipped laboratory, would
have to be run on a fairly large sampling of any one lot, and might not
group the sponges in exactly the same grade classes as the presently
accepted sensory tests numbers. Also, he pointed out that recommenda-
tions from himself and from the Exchange could not constitute a first
draft of new grading standards, but would be of definite assistance to
the Government in setting up these standards for their own purchasing
agents and for only the Government at presente

9. After comparison of the weight-size relationships that existed
before World War II, during the war, and in the present voluntary well-
washed standards accepted by most of the industry, it was recommended
that Federal Specification C-S-63lb, Paragraph 1-3 be recommended for
universal acceptance, and that the then superfluous columns of "Number
of Sponges per pound" be eliminated from the Specifications. It was

eS)

believed that the grading work in progress on cleanliness would help
to eliminate the need for the weight standards. The present perimeter
measurements were preferred over the three-axis method described by
Dr. Bennett. It was agreed that the present practice of marketing
sponges by size is to be recommended. It was agreed that the present
practice of checking size by only one "go-no-go" ring is inadequate
and that perimeters should be used instead.

10. In more detail, it was recommended that the following changes
be made in the Federal Specifications C-S-63lb. Parts not mentioned are
acceptable as they stand. A section should be added to clarify grading
by tests similar to those being developed by Dr. Bennett. Types may
then eventually reach a status of secondary importancee

It is recommended that Federal Specifications C-S-63lb should be
changed to read:

B-1-Type I - Rock Island Sheepswool, No. 1 forms and cuts mixed
with not less than 33% forms.

Type II - Florida key sheepswool, No. 1 forms and cuts mixed
with not less than 33% forms.

Type III - Florida yellow, No. 1 forms and cuts mixed with not
less than 33% forms.

Type VI - Rock Island sheepswool, No. 2 forms and cuts mixed
with not less than 33% forms.

Type VII - Florida key sheepswool, No. 2 forms and cuts mixed
with not less than 33% forms.

Type VIII - Florida yellow, No. 2 forms and cuts mixed with not
less than 33% forms.

Type IX, X, XI to be deleted.

gt

Type XII - Change "honeycomb" to Bengasi, No. 1 forms and cuts
mixed with not less than 33% forms.

Type XIII - Cuban sheepswool, No. 1 forms and cuts mixed with not
less than 33% forms.

Type XIV - liediterranean Bengasi, No. 2 forms and cuts mixed
with not less than 33% forms.

Type XV - Mediterranean deep water, No. 1 forms and cuts mixed
with not less than 33% forms.

Type XVI - Mediterranean deep water, No. 2 forms and cuts mixed
with not less than 33% forms.

Type XVII - Florida sheepswool inshore type, No. 2 forms and
cuts mixed with not less than 33% formse

Type XVIII - Anclote grass, No. 1 forms and cuts mixed with not
less than 33% forms.

Type XIX - Anclote grass, No. 2 forms and cuts mixed with not
less than 33% forms.

56

Type XX — Hudson grass, No. 1 forms and cuts mixed with not
less than 33% forms.

Type XXI - Hudson grass, No. 2 forms and cuts mixed with not
less than 33% formse

Ee Change type descriptions to agree with the above recommendations.
Delete the columns headed "Number of Sponges per Pound", Make all size
alphabet classifications consistent. For instance size D should be
"36" average, minimum" for all types of sponges. Add proportional size
classifications to increase the number of sizes to 8 in Types I, III
and VIII.

F-3ae In the last sentence the wording allows one perimeter to be
taken over a small end. It would be clearer if these words were added
to the sentence: "with the axis of intersection passing through the
approximate center of the sponge."

G-la. In view of the prevailing methods of buying and the insurmount—
able obstacles offered when sponges are marketed on a weight basis, it
is recommended that the phrase '50 to 57 pounds to the bale" be replaced
by the phrase "to correspond to the buyers! preference as to number per
package."

G=1b. In view of wording recommended in Gla, this paragraph may be
deleted.

I. This section should be reworded to correspond to the above changeSe
Further changes will have to await the results of the tests being run
at the University of Florida.

1-2¢ and -2h. In order to discourage violation of the "5 inch" law,
"(3—inch)" should be replaced by '(3-inch cut sponge)", and the sen—
tence giving designations in pounds should be deleted or replaced by
one containing designations in perimeters of "sponge cuts."

11. The members voted unanimously that it be recommended that
the"types" be rearranged and renumbered to give a more logical arrange-
ment by source of the sponges, such as:

Domestic: West Indies:

Type (—)e ~ Rock Island --- Type (--). - Key West Group ---
Type (--). -— Sheepswool, Inshore --- Type (--). - Cuban -—

Type (--). - Yellow --- Mediterranean:

Type (--). - and so forth

Type (--). - Hudson Grass ---

Type (--). - Anclote Grass -—
57

BIBLIOGRAPHY
ANDERSON, A. We
195h. Voluntary Federal standards for fishery products. Gulf
and Caribbean Fisheries Institute, Nov. 15-19, Annual
Sessione
BUTLER, CHARLES
195i. Voluntary Federal grade standards for fish sticks. Gulf
and Caribbean Fisheries Institute, Nove 15-19, Annual
Sessione
DAWSON, C. Ee, JR. and SMITH, F. G. WALTON
1953- The Gulf of Mexico sponge investigation. Florida Board
of Conservation, Tech. Series No. 1, March, through
U. of Miami Marine Laboratory (See also "The: Sponge
Industry of Florida," Education Series No. 2, Jan.
199)
DE LAUBENFELS, M. W.

1953ae A guide to the sponges of eastern North America. U. of
Miami Press, March, 32 pageSe

DE IAUBENFELS, M. W.

1953be Sponges from the Gulf of Mexico. Bulletin of Marine
Science of the Gulf and Caribbean, vol. 2, Noe 36

HAMMAR, A. Re

1956. Synthetic item is huge success. New York Times, Feb—
ruary 19, page le

KAHN, R. A.
1950a. Is the natural sponge fishery doomed by synthetic sponges?
Gulf and Caribbean Fisheries Institute, Annual Session,
Novembere

KAHN, ee Ae

1950 be The legislative situation on sponges. Branch of Com
mercial Fisheries, U. S. Fish and Wildlife Service.

KLEISSLER, C. Je

1955. U. S. Testing Company, letter of Nov. 28.

58

MONTELL, B. S.
1955. Descriptive literature on proposed standards for various
synthetic sponges. Society of the Plastics Industry,
August 19.
NOLTE, A.
1955. Development and promlgation of voluntary Federal stan-
dards and inspection of frozen breaded shrimp. Gulf
and Caribbean Fisheries Institute (speech), Oct. 31.
SNEDECOR, GEORGE W.
1916. Statistical methods. Iowa State College Press, Ames, Lowa.
SPANGLER, R. Le
196. Standardization and inspection of fresh fruits and vege-
tables. U. S. Department of Agriculture. Prod. and
Marketing Adm., Misc. Pub. No. 60h, October.
STUART, A. He

World trade in sponges. U. 5S. Dept. of Commerce, Induste
Series No. 82, U. S. Govt. Printing Office, 30¢, 95 ppe

SUTHERLAND 9 F. Le

1951. U. S. standards for grades of canned pears, CFR 7,
Section 522527, December 1.

SUTHERLAND, F. Le
1953. U. S. standards for grades of canned lima beans. U. S.
Dept. of Agriculture, Prod. and Marketing Adm. CFR 7;
Section 52.169, June 23.
SUTHERLAND, F. Le

195he U. Se standards for grades of frozen mixed vegetables,
Ag. Marketing Service, May 2h.

U. S. DEPT. OF AGRICULTURE

198. U. Se standards for grades of frozen grapefruit. Prode
& Marketing Adm., CFR 7, Section 52.36, Feb. 206

U. S. DEPT. OF AGRICULTURE

195ha.e Frozen French fried potatoes, U. S. standards for gradese
Ag. Marketing Service, CFR 7, Part 52, May 20, issue

of Federal Registere

59

U. S. DEPT. OF AGRICULTURE
195lb. Processed fruits and vegetables, processed products
thereof, and certain other processed food productse
Title 7, Chap. 1, Part 52, July 1. Subpart—-Regula-
tions governing inspection and certificatione
U. S. DEPT. of INTERIOR
195i. Development and promvigation of voluntary Federal stan-
dards and inspection of fishery products. Fish and
Wildlife Service, Nov. 2.
U. S. DEPT. OF INTERTOR
1955. United States standards for grades of frozen fried fish
sticks. Sept. 8, Provisional Draft. (Also revision
of Feb. 23, 1956.
WALLACE, D. H.

1955. Can natural sponges meet synthetic competition? Speech
for Sponge and Chamois Institute.

INT.-DUP. SEC., WASH., D.C. 45415

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OBSERVATIONS OF

MOULTING FEMALE KING CRABS
PARALITHODES CAMTSCHATICA

Dy

SPECIAL SCIENTIFIC REPORT-FISHERIES No. 274

UNITED STATES DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE

EXPLANATORY NOTE

The series embodies results of investigations, usually of restricted
scope, intended to aid or direct management or utilization practices and as
guides for administrative or legislative action. It is issued in limited quantities
for official use of Federal, State or cooperating agencies and in processed form
for economy and to avoid delay in publication.

United States Department of the Interior, Fred A. Seaton, Secretary
Fish and Wildlife Service, Arnie J. Suomela, Commissioner

OBSERVATIONS OF MOLTING FEMALE KING CRABS
(Paralithodes camtschatica)

by

Henry M. Sakuda
Fishery Research Biologist

Contribution No. 4 to research conducted with the
approval of the United States Section of the International
North Pacific Fisheries Commission. The Commission, es-
tablished in 1953 by the International Convention for the
High Seas Fisheries of the North Pacific Ocean, coordinates
the research of the member nations: Japan, Canada, and the
United States. The resulting investigations provide data
to the Commission for use in carrying out its duties in
connection with fishery conservation problems in the North
Pacific Ocean. Publication of this scientific report has
been approved by the United States Section of the Commission.

Special Scientific Report--Fisheries No. 274

Washington, D. C.

December 1958

The Library of Congress has cataloged this publication
as follows:

Sakuda, Henry M
Observations of moulting female king crabs (Paralithodes
camtschatica) Washington, U. S. Dept. of the Interior,
Fish and Wildlife Service, 1958.

op. illus. 27 em. (U.S. Fish and Wildlife Service. Special
scientific report: fisheries, no, 274)

Includes bibliography.

1. Paralithodes camtschatica. 1. Title. (Series)
SH11.A335 no. 274 595.3844 59-60427

Library of Congress

The Fish and Wildlife Service series, Special Scientific
Report--Fisheries, is cataloged as follows:

U.S. Fish and Wildlife Service.
Special scientific report: fisheries. no. 1-
,Washington, 1949-

no. illus., maps, diagrs, 27cm.
Supersedes in part the Service's Special scientific report.

1, Fisheries—Research.

SH11.A335 639.2072 59-60217

Library of Congress (2)

ABSTRACT

This report describes the observations of 9 molting
mature female king crabs (Paralithodes camtschatica) caught in
Pavlof Bay on the Alaska Peninsula between May 1 and May 18,
1957. Observations showed that the molting soft-shelled crabs
emerge through an opening between the posterior margin of the
carapace and anterior margin of the abdominal segments. The
female crabs all cast their shells without the males being
present. The remaining cast shells were intact, without
breaks in the shell parts. The maximum growth of the newly

molted crabs was attained 2 days after molting.

Introduction . .»

TABLE

°

°

Premolting observations.

Molting observations . .

Postmolting observations

Summary. «© 0 © © 2 «© «© 3»

Literature cited .

°

OF CONTENTS

OBSERVATIONS OF MOLTING FEMALE KING CRABS
(Paralithodes camtschatica)

INTRODUCTION

The Pacific Salmon Investigations of
the U. S. Fish and Wildlife Service is
conducting studies to determine the need
for measures for conservation of the
eastern Bering Sea king crab (Paralithodes
camtschatica), as part of the research pro-
gram of the International North Pacific
Fisheries Commission. In this respect,
knowledge of the biology of the king crab
is essential.

Molting, an important phase in the
life history of king crab as well as other
crustacea, is a phenomenon whereby the
exoskeleton is periodically discarded.
Generally all the outer cuticular layers
of the shell, eyes, antennae, gills,
tendons, mouth parts, esophagus, and
stomach with its chitinous teeth are re-
placed, leaving no apparent trace of this
change. The age of the crab, therefore, is
extremely difficult to determine. One of
the methods of estimating age is to rear
crabs in order to observe the molting
frequency and measure the growth attained
from molting. These measurements combined
with those obtained by sampling the fishery
then may give some indicationsof age.

This report describes the observations
of nine molting female king crabs caught in
Pavlof Bay on the Alaska Peninsula between
May 1 and 18, 1957. Work was done aboard
the MV Deep Sea, a king crab factoryship.

I em grateful to Wakefield's Deep
Sea Trawlers Inc. and the crew of the
vessel for their cooperation and the use
of their facilities. My thanks also to
Mr. Glen Davenport for his assistance, and
Mr. T. 0. Duncan for photographs.

PREMOLTING OBSERVATIONS

The annual molting and mating period
of female king crabs occur in the spring.
At this time the male is observed holding
the meropodite of the chelipeds of the
female with his chela. After the female
molts, the male leaves the cast shell and
resumes the original "hand shaking" position
with the soft-shelled female. The female

then lays new eggs which attach to the
swimmerets in the abdominal pouch and are
fertilized. Shell-casting, however, can
take place without the male.

Upon capture, the crabs were placed
in live boxes provided with running sea
water. For identification each crab was
marked with a number on the carapace be-
fore and after molting. Carapace length
measurements and examinations were made
daily from the time of capture until re-
lease.

The nine female specimens in a pre-
molting condition had similar external
characteristics. The shells of the cara-
pace and appendages were thin and pliable.
The membranes connecting the shell parts
were also very thin and cellophane-like in
texture. A slight pink color, differing
from the opaque color found in crabs of
nonmolting condition, was detected under
the thin membranes at the joints of each
leg and between the plates of the abdomen.
On one specimen the suture along the
anterior border of the first abdominal
segment was split and the pink soft shell
exposed. (See figure 1 for arrangement of
the abdominal segments.) The eyes of the
specimens were bright red in contrast to
the brown colored eyes of nonmolting crabs.

Prior to molting, the female crabs
were observed with their bodies lifted off
the bottom of the live box. Their abdomens,
extended away from their bodies, moved
rhythmically back and forth exposing the
swimmerets covered with empty egg cases.
This behavior was seen frequently until
molting and may be beneficial in releasing
zoea, larvae as well as loosening the soft
shell from the old, making extraction
easier during the shell-casting process.

MOLTING OBSERVATIONS

The first step observed in the shell-
casting process was a separation in the
thin membrane anterior to the first abdomi-
nal segment. (See figure 1 for arrange-
ment of the membrane connecting the

Figure 1.--Posterior view of king crab showing arrangement of carapace and

abdominal segments.

(After Marukawa, 1933.) 1, posterior

border of carapace; 2, isthmus between carapace and body; 3,
first abdominal segment; 4-6, second abdominal segments; me-
median plate, la- lateral plate, ma- marginal plate.

carapace and abdomen). The carapace and
abdominal segments then started to part,
thus tearing the membrane further and
opening a large gap. The tear in the
membrane extended completely along the
anterior margin of the abdominal segments,
vertically up the isthmus between the
carapace and body, and completely across
the posterior margin of the carapace. As
the membrane continued to tear, the open-
ing grew larger and the soft-shelled crab
backed out of the old shell. During the
only occasion when a crab was timed cast-
ing its shell, four minutes were required
to back out of the old shell.

Meny females examined during trawl-
ing operations were found with the membrane
along the first abdominal segment split
and this section open.

POSTMOLTING OBSERVATIONS

Seven of the nine cast shells re-
mained intact. The membranes connecting
the sides of the carapace to the body
shell did not separate (fig. 2), except
for the section between the carapace and
abdominal segments. In the other two,
the thin membranes in other parts of the
cast shells were torn and parts lost.

The outer layers of the antennae,
eyes, gills, stomach, and mouth parts were
entirely left with the old shells; the
tendons of the legs were also left in the
cast shells. One specimen sloughed off
its left fourth leg at the basal segment
and left it in the cast shell. This crab
would probably regenerate a new leg.

*[TTeUsS PTO eu Worl sesiews qero eu, YoTyM
usno1yuy Sutuedo Sutmoys qeto suTH eTewes Jo TTays yseo YoeqUT JO MOETA AOTALEYSOg--*%¢2 WUNILA

The length measurements of the cara-
pace of the newly molted crabs showed some
fluctuations during hardening, which lasted
from 3 to 4 days. In all cases, however,
the specimens which were held from 5 to
13 days after molting showed the initial
growth measured 2 days after molting to be
the total growth. Growth from molting
ranged from 2 to 6 m., with an average of
4 mm. as shown in table 1 and figure 3.

Except for one specimen, all the
newly molted females failed to lay eggs.

Wallace et al. (1949) states, "a
simultaneous action is exerted by the
tissue under the carapace, leading to
breaks on the sides, posterior end, and,
in some cases, entirely across the cara-
pace. Very often the old shell is left
completely intact except for the breaks
along the sides of the carapace". In the
present study seven of the cast shells
remained completely intact, except for the
torn membrane on the posterior end of the
carapace. In all nine crabs the carapace
and leg shells were not cracked.

Growth measurements from this study
(fig. 3) agree closely with the growth of
females from tagging and molting studies
deseribed by Wallace et al. (1949) and
Stevens (1955). The 3 to 4 days taken
for shell-hardening agrees with the average
days required for growth and hardening
mentioned by Marukawa (1933).

Wallace et al. (1949) states that
Pemale crabs allowed to molt in the
absence of males do not extrude their eggs
until permitted to mate. In this study,
however, one of the nine females extruded
eggs a day after molting.

SUMMARY

1. Before molting the females were
observed rhythmically moving and stretch-
ing their abdomens.

2. The female crabs cast their
shells without the males being present.

3- Most of the shells cast were
intact except for the split in the membrane
connecting the carapace to the abdominal
segments.

4. One shell-casting process was
timed at 4 minutes.

5- All but one of the newly molted
females failed to lay eggs.

6. Size measurements fluctuated
during shell-hardening; however, the
growth measured 2 days after molting was
the total growth.

7. The amount of growth ranged from
2 to 6 m., with an average of 4 m.

LITERATURE CITED

MARUKAWA, HISATOSHI
1933. Biology and Fishery Research of
Japanese King Crab, Paralithodes

camtschatica (Tilesius), J. imp.
Expr. Sta. Tokyo, 4 (37): 152 pp.

STEVENS, HIRAM REED, JR.
1955. Progress Report on King Crab
Research, Annual Report No. 7,
Alaska Dept. of Fish., pp. 87.

WALLACE, M. M., C. J. PERTUIT, AND
A. R. HVATUM
1949. Contribution to the Biology of
the King Crab (Paralithodes
camtschaticea (Tilesius), Fish.
Leaf. 340, U. S. Dept. of Interior,
Fish and Wildlife Service, pp. 27.

NO CO sce ONG

Carapace Length Growth (mm.)

Table 1.--Dimensions of nine molting female king crabs

Original Carapace Days held
carapace length at from
length release Growth molt to

Im. HER. mn. ) release
TUS 120.0 5.0 10
118 121.0 3.0 13
119 122.0 3-0 10
120 122.0 2.0 13
123 127.0 4.0 12
127 132.0 5.0 T
131 136.0 5.0 13
131 137.0 6.0 5
141 144.5 3-5 12

xx

110 120 130 140
Carapace Length Before Moulting (mm.)

Figure 3.--Growth of nine female king crabs
from molting.

5 INT.-DUP. SEC., WASH., D.C. 48433

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