poe A NEW NEMATODE, OSTERTAGIA BULLOSA, |
PARASITIC IN THE ALIMENTARY
TRACY OF. SHEEP

BY

BRAYTON HOWARD RANSOM

Assistant Custodian, Helminthological Collections, United States National Museum

AND

MAURICE C. HALL

Assistant Zoologist, Bureau of Animal Industry, United States Department of Agriculture

No. 1892,—From the Proceedings of the United States National Museum,
; Vol. 42, pages 175-179

Published February 28, 1912

e0028S30o0

Washington

Government Printing Office

1912

A NEW NEMATODE, OSTERTAGIA BULLOSA,
PARASITIC IN THE ALIMENTARY
RACE OF SHEEP

BY

BRAYTON HOWARD RANSOM

Assistant Custodian, Helminthological Collections, United States National Museum
oo

AND

MAURICE C. HALL

Assistant Zoologist, Bureau of Animal Industry, United States Department of Agriculture

No. 1892.—From the Proceedings of the United States National Museum,
Vol. 42, pages 175-179

Published February 28, 1912 _

S6ecage0?'

Washington
Government Printing Office
1912

A NEW. NEMATODE, OSTERTAGIA BULLOSA, PARASITIC
IN THE ALIMENTARY TRACT OF SHEEP. |

By Brayton Tlowarp Ransom,
Assistant Custodian, Helminthological Collections, United States National Museum,

AND

Mavurick C. Harn, }
Assistant Zoologist, Bureau of Animal Industry, United States Department of Agriculture.

Tho nematode described in this paper was first collected by the
junior author at an abattoir in Colorado Springs, Colorado, April 28,
1911. Comparison with the descriptions of species given in Ransom
(1911) led to the conclusion that the species was probably new.
Specimens were then sent to the senior author who also was of the
opinion that it was a new species. The sheep from which this ma-
terial was collected were originally from the ranch of Mr. W. Tf. Wells
near Resolis, Colorado, and specimens of the nematode here described
were collected by both of us during the summer of 1911 from sheep at,
Mr. Wells’s ranch. The nematode was found in nearly every sheep
examined at the ranch and was the only nematode found in the
stomach with the exception of the stomach worm, /Tamonchus con-
tortus. ‘The new species was also found by us in sheep at the ranch
of Mr. W. T. Kennedy near Amo, Colorado. A single specimen was
found once in the intestine, but the occurrence of this nematode in the
intestine was probably accidental, as the fourth stomach is evidently
the normal location, In Colorado the greatest number of Ostertagia
found in a single sheep was 73 and the greatest number of Hamonchus
contortus, 537. Usually there were less than a dozen of each. This
comparative freedom from infection with nematodes in Colorado
sheep is to be attributed in part to the dry climate and in part to the
extensive area covered in range feeding, thereby preventing concen-
tration of infection.

Mr. W. D. Foster of the Zoological Division, Bureau of Animal
Industry, has called our attention to a single specimen of a nematode,
a female, collected by him May 13, 1910, from a sheep received in

PROCEEDINGS U. S. NATIONAL Museum, VoL. 42—No, 1892,
175

176 PROCEEDINGS OF THH NATIONAL MUSEUM. VOL. 42.

Washington from Montana. This specimen he had been unable to
identify with any described species. Examination shows that it is
of the same species as that collected by us in Cohorado. Ostertagia
bullosa is therefore known to occur in two of the Rocky Mountain
States. Two other species of this genus have been found thus far only
in the Rocky Mountain region, namely Ostertagia marshalli and O.
occidentalis, these two being reported heretofore only from Montana.
To these records may be added our finding, in 1911, at a Denver
abattoir, of O. marshalli in sheep from Wyoming and Utah, and of
O. occidentalis in sheep from Wyoming.

The new species is white when freshly collected and has the usual
characteristics of the genus Ostertagia, but differs from other species
of the genus in that the two ventral rays of each lateral lobe of
the bursa are rather widely divergent, the spicules are simple and
not split into several processes posteriorly, and the gubernaculum
is of the same yellow-brown color as the spicules instead of being
colorless.

In the key given in Ransom (1911) this species runs down to
Ostertagia trifurcata of which only the male is known. In several
respects, however, it differs from trifurcata. The gubernaculum in
O. trifurcata is a narrow colorless structure, whereas in O. bullosa it is
a yellowish-brown structure, irregularly trihedral in shape. The
spicules in O. trifurcata are twisted but are not curved in theirlong
axis, and are divided into 3 processes at the posterior end. The
spicules in O. bullosa are narrow, curving, tubular structures, not
divided at the posterior end which is acutely pointed. Each of the
two terminal branches of the dorsal ray in O. trifurcata has a short
process on the outer side and one on the inner. 0. bullosa has a short
process on the outer side, but the process on the inner side is only sug-
gested by a slight and often indistinct. bifurcation at the tip.

The principal characters of O. bullosa are as follows:

OSTERTAGIA BULLOSA Ransom and Hall, 1912.

Specific diagnosis.—Ostertagia: Male (fig. 1) about 7.3 mm. long.
Maximum thickness 115 y just in front of bursa. Diameter of head
17 4; diameter of body at level of nerve ring 44 to 48 y, at base of
esophagus 68 y. Esophagus 510 to 545 win length, surrounded by a
nerve ring at a distance of 220 to 250 « from the anterior end. The
excretory pore is situated about 270 » from the anterior end of the
body. Cervical papille not evident. The esophagus increases in
diameter from 16 » anteriorly to 45 or 50 4 at its posterior end. The
bursal membrane has a very distinct longitudinal striation. The
median lobe is only slightly shorter than the lateral lobes. The lateral
lobes are usually partly folded over each other in their ventral por-
tions. The ventro-ventral (fig. 2, v. v.) and latero-ventral (fig. 2, 0. v.)

no. 1892. A NHW PARASITIC NEMATODE—RANSOM AND HALL, TET

rays diverge considerably, which is unusual in the genus Ostertagia,
and their tips are at least half as far apart as the tips of the latero-
ventral and externo-lateral rays. The distance between the tips
of the externo-lateral and medio-lateral rays is much less than that
between the latter and the tip of the
postero-lateral ray. Of the paired
rays, the latero-ventral is the thickest.
Following this in the order of size are

Imm.

imm.

Fig. 1—OSsTERTAGIA BULLOSA. MALE AND
FEMALE. *VULVA. ENLARGED.

the externo-lateral (fig. 2, ¢./.),
then the ‘medio-lateral (fig. 2,
m.1.), the postero-lateral (fig.
2, p.l.), and the externo-dorsal
(fig. 2, e. d.), which are of about
the same size, and lastly the
ventro-ventral. The dorsal ray
(fig. 2, d.) is about 140 » long
and is bifurcated 25 to 40 p»
(00,4. from its posterior end. The
Fig. 2.—OSTERTAGIA BULLOSA. POSTERIOR END OF terminal branches have each a
BODY OF MALE, VIEWED FROM LEFT SIDE. bul., PREBUR- =
SAL BULLA; d., DORSAL RAY; ¢. d., EXTERNO-DORSAL small branch, sometimes re-
RAY; ¢.1., EXTERNO-LATERAL RAY; gub., GUBERNACU- duced to a mere knob, on the
LUM; I. v., LATERO-VENTRAL RAY; ™. 1., MEDIO-LATERAL : Z
RAY; p. l., POSTERO-LATERAL RAY; Sp., LEFT SPICULE} outerside. At times each of the
v. V., VENTRO-VENTRAL RAY. ENLARGED. terminal branches ends in a very
small fork and at times appears to end without forking. The spicules
(fig. 2, sp.) are 140 to 180 » long and 15 to 20 « wide at the anterior
end. They gradually narrow toward the posterior end, which is
pointed, and do not fork. Usually the tips are curved but in some

20441°—Proc.N.M.vol.42—12 12

178

PROCEEDINGS OF THE NATIONAL MUSEUM.

VOL. 42.

specimens they appear to be straight.

The gubernaculum (fig. 2,

gub.) is irregularly trihedral in shape, somewhat resembling a plow-

1OOpA.

Fic. 3.—OSTERTAGIA BULLOSA. TAIL
OF FEMALE, VIEWED FROM LEFT SIDE.
SNLARGED.

share in outline when viewed from
the side, and prolonged into a
short slender process anteriorly,
Measured from the side it is about
25 » wide and 65 wlong. It is of
the same yellow-brown color as
the spicules.

A well-marked character of this
species is a prominent cuticular
swelling anterior of the bursa on
the ventral surface (fig. 2, bul.).
For some distance anterior of the
swelling the cuticle on the ventral

ba.

FIG. 4.—OSTERTAGIA BULLOSA. REGION OF
VULVA OF FEMALE, VIEWED FROM LEFT
SIDE. €¢., EGG; lab., RUDIMENTARY CUTIC-
ULAR FLAP ANTERIOR OF VULVA; 0vij. 1,
TERMINAL PORTION OF OVIJECTOR; 0vij. 2,
SPHINCTER OF OVIJECTOR; ovij. 3, NONMUS-
CULAR PORTION OF OVIJECTOR; Ut., UTERUS;
vul., VULVA. ENLARGED.

surface is somewhat thickened and at a distance of 100 to 125 yw in
front of the bursa the cuticle splits to form this swelling. When

no. 1892. A NHW PARASITIC NEMATODE—RANSOM AND HALL. 179

viewed from the side, the optical section of the cuticle forming the
ventral boundary of the swelling is usually oval but sometimes has a
more rectangular outline, resembling somewhat the trigger guard on
a rifle. ,The swelling is apparently filled with a clear transparent
fluid. The prebursal papille are located near the lateral limits of
this swelling and about 15 » in front of the anterior edge of the bursa.
- SHemale (fig. 1), 8.8 to 9.8 mm. long by about 13 » wide in the region
of the vulva. The head measures 20 to 25 » in diameter. At the
nerve ring the body is 50 to 60 yin thickness, at the base of the esoph-
agus 70 to 80 », and at the anus 50 to 55 yw. The esophagus is 580
to 620 » long and is surrounded by a nerve ring 220 to 255 » from the
anterior end. The excretory pore is 265 to 320 » from the anterior
end. Cervical papille not evident. The vulva (fig. 4, vul.) is trans-
versely elongated, commonly presenting a crescentic outline with the
convexity of the crescent directed posteriorly. At times a very
small, rudimentary cuticular flap (fig. 4, lab.) is evident. The vulva
is situated 1 to 1.3 mm. from the posterior end of the body. The tail
(fig. 3) tapers posteriorly, always curving ventrally and usually
curving more sharply near the end to form a rather open hook, which
terminates in a slightly enlarged, rounded tip. The cuticle of the tail
beginning in the anal region and extending to the tip is marked by
very fine transverse striations close together. The anus is situated
120 to 150 w from the tip of the tail. The cuticle surrounding the
anus is usually swollen so that a prominence appears at this point
25 to 35 win diameter and 5 to 8 w high. The combined length of the
muscular portions of the ovijectors (fig. 4, ovij.), including the sphinc-
ters, is 220 to 360 ». The maximum size of the eggs(from measure-
ments of eggs observed in the ovijectors) is 85 long by 65 p» wide
(fig. 4, e.).

Host.—Ovis aries.

Location.—Fourth stomach.

Localities collected —Colorado; Montana.

Type-specumens.—Cat. No. 16083, U.S.N.M. (Bureau of Animal
Industry Helminthological collection); collected July 30, 1911, at
Wells’s ranch, Resolis, Colo., by B. H. Ransom from the fourth
stomach of a sheep.

REFERENCE.
Ransom, B. H. 1911. The nematodes parasitic in the alimentary tract of cattle,

sheep, and other ruminants. Bull. 127, Bureau Animal Ind., U. 8. Dep. Agr.,
Washington, 132 pp., figs. 1-152.

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