ae Postilla

Number 226
14 August 2002

The Genus Podocerus
(Crustacea: Amphipoda: Podoceridae)
from Guana Island, British Virgin Islands

Adam J. Baldinger

Michael F. Gable

Peabody Museum of Natural History « Yale University - New Haven, Connecticut

Postilla

Curatorial Editor-in-Chief
Jacques Gauthier

Executive Editor
Lawrence F. Gall

Publications Editor
Rosemary Volpe

Publications Assistant
Joyce Gherlone

Published at irregular but frequent intervals since 1950, Postilla presents short papers based on orig-
inal scientific research by Museum staff and research associates, and their colleagues, in the natural
science disciplines represented by the collections of the Yale Peabody Museum’s curatorial divisions.

All manuscript submissions are sent out for external peer review by one or more referees, as well
as being reviewed internally at the Yale Peabody Museum by the Executive Editor in consultation
with the Curatorial Editor-in-Chief and one or more members of the appropriate curatorial divi-
sion. Interested authors should contact the Executive Editor at the address below before submit-
ting manuscripts.

Other series published by the Yale Peabody Museum are the Bulletin of the Peabody Museum of Nat-
ural History and the Yale University Publications in Anthropology. A complete list of titles, availability
and ordering information, along with submission guidelines for contributors, can be obtained from
the Yale Peabody Museum website at http://www.peabody.yale.edu/ or requested from the Publica-
tions Office at the address below.

Address correspondence to:

Publications Office
Peabody Museum of Natural History
Yale University

170 Whitney Avenue Phone: (203) 432-3786
P.O. Box 208118 Fax: (203) 432-5872
New Haven, CT 06520-8118 USA E-mail: peabody.publications@yale.edu

Copyright © 2002 Peabody Museum of Natural History, Yale University. All rights reserved.

No part of this book, except brief quotations by reviewers, may be used or reproduced in any form
or media, electronic or mechanical (including photocopying, recording, or by any information
storage and retrieval system), without the written permission of the Peabody Museum of Natural
History, Yale University, New Haven, Connecticut, U.S.A.

ISSN 0079-4295
ISBN 0-912532-59-9

Printed in the U.S.A.

This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper).

The Genus Podocerus

(Crustacea: Amphipoda: Podoceridae)
from Guana Island, British Virgin Islands

Adam J. Baldinger

Museum of Comparative Zoology, Harvard University

Michael F. Gable
Eastern Connecticut State University

(Received 5 October 2001; revised and accepted 26 April 2002)

Abstract

A new species of Podocerus is described
from Guana Island, British Virgin Islands.
Podocerus jareckii n. sp. has dorsal carina-
tions and an interramal spine on

uropod 1. A second species of Podocerus
collected from similar habitats lacks dor-
sal carinations and uropodal interramal
spines; it is indistinguishable from Podo-
cerus fissipes described from the coast of
Brazil. The relationships of the species
reported here to Podocerus found in
Bermuda, and in the Caribbean and
Mediterranean Seas, are discussed.

Keywords

Caribbean Sea, new species, Podocerus

fissipes, new record, zoogeography.

Postilla 226 - 14 August 2002

Introduction

In general, the amphipod species of the
Caribbean region are known from spo-
radic records and from descriptions of
single species associated with specific areas
or islands (Baldinger 2000). Other than an
identification manual for the common
marine amphipods of southern Florida
(Thomas 1993), and a pictorial key to the
families and genera of the tropical western
Atlantic Ocean (Ortiz 1994), no mono-
graphs on the amphipods from the
Caribbean have been published. Thomas
(1993) recognized three podocerid amphi-
pods from southern Florida: Podocerus
kleidus Thomas and Barnard 1992, Podo-
cerus brasiliensis (Dana 1853), and Podo-
cerus chelonophilus (Chevreux and de
Guerne 1888). In contrast, the amphipod
fauna of the mid-Atlantic island of
Bermuda has been relatively well studied
(Kunkel 1910; Lazo-Wasem and Gable
1987, 1989; Gable and others 1988; Lazo-
Wasem and others 1989; Gable and Lazo-
Wasem 1990; Baldinger and Gable 1994,
1995; Ruffo and others 2000). Podocerus

© 2002 Peabody Museum of Natural History, Yale University

2 Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

Figure 1
Podocerus jareckii. YPM 24061, female, 2.8 mm.

tachyrheo Baldinger and Gable 1994 and distributional record for the Caribbean.
Podocerus lazowasemi Baldinger and Gable __ Reanalysis of type material has revealed
1994 are considered endemic to Bermuda. that some of Serejo’s (1995) characters

Examination of specimens found were inaccurately or incompletely de-
living in sponges or in association with scribed, and we discuss these discrepan-
coral rubble from Guana Island, British cies below.

Virgin Islands, has added one new species,

Podocerus jarecki1, to the Caribbean am- Materials and Methods

phipod fauna. A second species was found

in habitats similar to those of P. jareckii. Guana Island (lat 18°28’24’N, long

This second species is indistinguishable 64°34’30”W) lies just north of Tortola in
from Podocerus fissipes Serejo 1995, origi- the British Virgin Islands, and is a small
nally described from the coast of Brazil. island of approximately 3 km2, with a

Its occurrence in Guana representsanew maximum elevation of 246 m. Amphi-

The Genus Podocerus
from Guana Island, B.V.I.

pods from Guana Island were collected by
E. A. Lazo-Wasem and A. J. Baldinger over
a six-year period (1995 to 2001) from as
many different microhabitats as possible.
Specimens were either hand-picked from
algal scrapings or screened from formalin
washes of specific substrates in the field,
and preserved in 70% EtOH. Samples
were then sorted to the lowest taxonomic
rank possible, and detailed investigations
of selected specimens were made under a
dissecting microscope. Mouthparts and
appendages were dissected and mounted
in glycerin on microscope slides. Morpho-
logical characters were described and
illustrations were made with the aid of a
camera lucida.

Type and voucher specimens are de-
posited at the Peabody Museum of Nat-
ural History, Yale University (YPM), and
at the Museum of Comparative Zoology,
Harvard University (MCZ). We also ex-
amined the types of P. fissipes deposited in
the Museu Nacional UF Rio de Janeiro
(MNR)J).

In the figures, body parts are marked
by the following abbreviations:

A antenna
Gn gnathopod
UL upper lip

LL lower lip
Md mandible
Mx maxilla
Mxpd_ maxilliped
P pereopod
Pl pleopod

T telson

U uropod

R right

L left

Gnathopods are numbered Gn1 and Gn2;
pereopods are numbered P3 through P7.

Postilla 226 3

Systematic Descriptions

PODOCERUS JARECKII, NEW SPECIES
Figures 1 through 5.

Material examined. YPM 24069, male
holotype, 2.1 mm, British Virgin Islands,
Guana Island, Monkey Point, west side;
formalin wash of purple-brown sponge;
depth 2 m; collector E. A. Lazo-Wasem
and A. J. Baldinger, 14 October 1999
[GUA 99-08]. YPM 24061, female
paratype, 2.8 mm, same data as holotype.
YPM 24062, male paratype, 2.2 mm, same
data as holotype. YPM 24063, male
paratype, 2.7 mm, same data as holotype.
YPM 24064, 3 paratypes, same data as
holotype. YPM 24066, male? paratype,

1.7 mm, same data as holotype. YPM
24067, male? paratype, 2.1 mm, same data
as holotype. YPM 24068, female paratype,
1.9 mm, same data as holotype. YPM
24065, male paratype, 2.4 mm, British
Virgin Islands, Guana Island, Crab Cove;
formalin wash of large pieces of coral rub-
ble; depth 3 m; collector E. A. Lazo-
Wasem and A. J. Baldinger, 13 October
1999 [GUA 99-01]. MCZ 37444, 5
paratypes, British Virgin Islands, Guana
Island, Monkey Point, west side; formalin
wash of purple-brown sponge; depth 2 m;
collector E. A. Lazo-Wasem and A. J.
Baldinger, 14 October 1999 [GUA 99-08].
YPM 24251, 2 males, 1 female (oviger-
ous), | juvenile, British Virgin Islands,
Guana Island, Bigelow Beach; on green
algae attached to Diploria sp.; depth 1 m;
collector A. J. Baldinger, 23 October 2000
[GUA 00-06]. YPM 24252, 2 males, 3 fe-
males (2 ovigerous), British Virgin Is-
lands, Guana Island, Bigelow Beach; on
flattened, light green sea rod; depth 1 m;

4 Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

“<ell Giga (

Figure 2
Podocerus jareckii. YPM 24062, male, 2.2 mm. Scale: a (Al, A2), 0.1 mm; b (UR), 0.1 mm.

The Genus Podocerus Postilla 226 5,
from Guana Island, B.V.I.

Figure 3

Podocerus jareckii. YPM 24062, male, 2.2 mm. Scale 0.05 mm.

The Genus Podocerus
from Guana Island, B.V.I.

Postilla 226

Figure 4
Podocerus jareckii. YPM 24062, male, 2.2 mm, Pl 1-3. YPM 24061, female, 2.8 mm. Scale 0.1 mm.

The Genus Podocerus Postilla 226 7
from Guana Island, B.V.I.

Figure 5
Podocerus jareckii. YPM 24062, male, 2.2 mm, P4—P7. YPM 24069, male, 2.1 mm, P3. Scale 0.1 mm.

8 Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

Figure 6
Podocerus fissipes, from Guana Island. YPM 24074, male, 3.0 mm.

collector A. J. Baldinger, 23 October 2000 articulate, each article with distinct
[GUA 00-07]. YPM 24253, 1 male, British — spines. Uropod 1, peduncle with distal

Virgin Islands, Guana Island, Bigelow interramal spine. Dorsal lobe of telson

Beach; on yellow-orange sponge; depth with 5 long spines.

1 m; collector A. J. Baldinger, 23 October

2000 [GUA 00-08]. Description. Male: 2.2 mm in length.
Body with dorsal carinations (Figure 1).

Diagnosis. Body with dorsal carinations. Pereonites 2 through 7 and pleonite 1

Pereonites 2 through 7 and pleonite | with dorsal spine groups. Head cuboidal,

with dorsal spines. Antenna 2 flagellum 3- _ slightly longer than pereonites 1 and 2.

The Genus Podocerus Postilla 226 9
from Guana Island, B.V.I.

Figure 7

Podocerus fissipes, from Guana Island. YPM 24075, male, 3.0 mm. Scale: a (UR), 0.1 mm; b (Al,
A2),0.25 mm.

Eyes pigmented. Coxae reduced, with aesthetascs; accessory flagellum 1-articu-

serial discontiguity. late. Antenna 2 (Figure 2) greater than
Antenna | (Figure 2), 60% of total antenna | in length, article 4 of peduncle

body length, peduncular ratio 1:2:1.7; 66% the length of article 5; flagellum

peduncle article 3 with plumose setae equal —_3-articulate, each article with distinct

to or longer than article length; flagellum spines.

3-articulate, each article bearing setae and Upper lip (Figure 3) rounded, anterior

10 Postilla 226

The Genus Podocerus
from Guana Island, B.V.I.

Table 1

Morphological variation in males of four species of Podocerus.

P. jareckit P. kleidus P. lazowasemt P. schieckei

2.2mm 4.5mm 3.3 mm 2.5mm
Type locality Guana, BVI Florida Keys, USA Bermuda = Mediterranean Sea
Interramal spines Present Present Present Absent
on uropod |
Interramal spines Absent Present Present Absent
on uropod 2
Number of spines 2 9 4 2.
on telson
Number of flagellar 3 6 5 :
articles on antenna |
Spines on flagellum Present Absent Present 2
of antenna 2
Morphology of Rectangular Cleft Rhomboidal Rectangular
coxal plate of
gnathopod |
Number of spines 1 3 0 1
on article 4
of gnathopod 2
Number of spines 2 1 4 1-2

between palm and
posterior margin
of gnathopod 2

margin slightly concave with fine setae.
Left mandible (Figure 3), molar tritura-
tive, with an accessory plumose seta, inner
margin with 3 plumose setae, incisor with
5 teeth, lacinia mobilis with 4 teeth; palp
3-articulate, terminal article clavate, with
facial and apical plumose setae. Right
mandible similar to left, but incisor and
lacinia moblilis both with 4 teeth. Lower
lip (Figure 3) normal, anterior margins
with fine setae. Maxilla 1 (Figure 3), inner

plate absent; outer plate with 5 apical
spines; palp 2-articulate, terminal article
with 4 apical spines and submarginal
setae. Maxilla 2 (Figure 3), plates subequal
in width, both with apical setae. Maxil-
liped (Figure 3), inner plate with marginal
and submarginal setae and a single inner
marginal spine; outer plate with inner
marginal spine row and submarginal
setae; palp 4-articulate, articles 2 and 3
with marginal plumose setae, terminal

The Genus Podocerus
from Guana Island, B.V.I.

Postilla 226 1]

eo ———————————————————SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

article shorter than article 3, with apical
plumose setae.

Gnathopod 1 (Figure 4), coxal plate
rectangular, with a distoanterior seta; basis
elongated; articles 5 and 6 subequal in
length, posterior margin of article 5 ex-
panded, with marginal and submarginal
setae, some plumose; palm of article 6
with marginal setae, some plumose; dacty!
extending to middle of article 5, bifurcate,
with one subterminal marginal spine.
Gnathopod 2 (Figure 4), robust and much
larger than gnathopod 1; article 4, disto-
posterior margin with plumose setae and a
single spine; articles 5 and 6 densely coy-
ered with plumose setae, palm of article 6
with irregular margin bearing a conical
tooth, hind margin demarcated distally by
two bifurcate spines. Pereopod 5 (Figure
5), basis forming distal posterior lobe with
2 marginal setae, and a proximal posterior
plate-like extension; pereopods 6 and 7
(Figure 5), bases each with a proximal
posterior plate-like extension; pereopods 3
and 4 (Figure 5) anterior margins of arti-
cle 6, and pereopods 5 through 7 posterior
margins of article 6 with stout setae.

Pleopods | through 3 (Figure 4) long
and slender, peduncles with 3 coupling
hooks; rami with plumose setae. Uropod 1
(Figure 2), peduncle with short interramal
spine; peduncle and rami with marginal
and apical spines; inner margin of inner
ramus minutely serrate. Uropod 2 (Figure
2), peduncle lacking interramal spine;
peduncle and rami with marginal spines,
rami with distinct apical spines; inner
margin of inner ramus minutely serrate.
Uropod 3 (Figure 2) vestigial, with single
marginal setule. Telson (Figure 2) dorsally
produced and armed with 5 long setae
arranged in a circular pattern.

Female: 2.8 mm in length. All features
same as male except as follows: gnathopod
1 (Figure 4), dactyl inner margin serrate,
medially and subterminally bifurcate and
not reaching middle of article 5; gnatho-
pod 2 (Figure 4), article 4 lacking spine on
distal margin; articles 5 and 6 not densely
covered with plumose setae; palm
straight.

Etymology. This species is named in
honor of Henry Jarecki, owner and pro-
prietor of Guana Island.

Remarks. Podocerus jareckii is similar to

P. kleidus from the Florida Keys, the
Bermuda endemic P. lazowasemi and the
Mediterranean Sea endemic Podocerus
schieckei Ruffo 1987 (see Table 1). Both

P. kleidus and P. lazowasemi have an inter-
ramal spine on the peduncle of uropods 1
and 2. Podocerus jareckii has an interramal
spine only on the peduncle of uropod 1,
and P. schieckei lacks uropodal peduncular
interramal spines. Podocerus jareckii can
also be distinguished from P. schieckei by
the spination of the urosome: P. schieckei
has longer apical spines on the rami of
uropods | and 2, and has 2 spines instead
of 5 on the telson. Other differences are
listed in Table 1.

PODOCERUS FISSIPES SEREJO 1995
Figures 6 to 12.

Serejo 1995: 49-57, figs. 1-3.

Material examined. YPM 24074, male,
3.0 mm, British Virgin Islands, Guana
Island, probably Monkey Point; depth
0.1 m; collector E. A. Lazo-Wasem and
A. J. Baldinger, 14-15 October 1999 [GUA

Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

Figure 8

Podocerus fissipes, from Guana Island. YPM 24075, male, 3.0 mm. Scale: a (Pl 1-3), 0.25 mm;
b (mouthparts), 0.1 mm.

The Genus Podocerus
from Guana Island, B.V.I.

Postilla 226 13

Figure 9

d Gn2 2

Podocerus fissipes, from Guana Island. YPM 24075, male, 3.0 mm. Scale 0.1 mm.

99-32]. All remaining specimens exam-
ined have the same collection data as YPM
24074, except as noted: YPM 24075, male,
3.0 mm; YPM 24073, female, 3.2 mm;
YPM 24070, 60 specimens; YPM 24071,
ovigerous female, 3.2 mm; YPM 24076,

3 males, 2.4 to 3.4 mm; YPM 24254, male,
2.8 mm; YPM 24255, male, 3.0 mm. MCZ
37445, 10 specimens, British Virgin Is-
lands, Guana Island, probably Monkey
Point; depth 0.1 m; collector E. A. Lazo-
Wasem and A. J. Baldinger, 14-15 October
1999 [GUA 99-32]. MNRJ 6423, male
holotype, 2.3 mm, Brazil, Rio de Janeiro,
at Prainha in Arraial do Cabo; collector

C. S. Serejo and L. Santi, 24 March 1994.

MNRJ 6431, male paratype, 2.8 mm, same
data as MNRJ 6423.

Diagnosis. Body smooth, without dorsal
carinations. Pereonites 5 through 7 and
pleonite 1 with dorsal spine groups. An-
tenna 2, flagellum 3-articulate, each article
with distinct spines. Uropods | through 3
lacking interramal spines. Dorsal lobe of
telson with 2 long spines.

Description. Male: 3.0 mm in length.
Body smooth, without dorsal carinations
(Figure 6). Pereonites 5 through 7 and
pleonite | with dorsal spine groups. Head
cuboidal, slightly shorter than length of

14 Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

Figure 10

Podocerus fissipes, from Guana Island. YPM 24254, male, 2.8 mm, P3—P5, P7. YPM 24255, male,
3.0 mm, P6. Scale 0.1 mm.

The Genus Podocerus
from Guana Island, B.V.I.

Postilla 226 l

wn

pereonites | and 2 combined. Eyes pig-
mented. Coxae reduced with serial dis-
contiguity.

Antenna | (Figure 7), 70% of total
body length, peduncular ratio 1:2:1.7,
peduncular articles 2 and 3 with plumose
setae equal to or longer than length of
each article, respectively; flagellum
4-articulate, with marginal plumose setae;
accessory flagellum 1-articulate. Antenna
2 (Figure 7) longer than antenna 1,
article 4 of peduncle 75% the length of
article 5; flagellum 3-articulate, each arti-
cle with distinct spines.

Upper lip (Figure 8) rounded, anterior
margin slightly concave, with fine setae.
Right mandible (Figure 8), molar tritura-
tive, inner margin with 3 stout spines;
incisor with 5 teeth, lacinia mobilis with
3 teeth; palp 3-articulate, terminal article
clavate, with facial and apical plumose
setae. Left mandible similar to right, but
incisor with 4 teeth and molar with an
accessory plumose seta. Lower lip (Figure
8) normal, anterior and inner margins
with fine setae. Maxilla 1 (Figure 8), inner
plate absent; outer plate with 6 apical
spines, center two spines bifurcate; palp
2-articulate, terminal article with 4 spines
and a submarginal plumose seta. Maxilla
2 (Figure 8), plates subequal in width,
both with apical setae; inner margin of
inner plate with 4 small spines and fine
setae. Maxilliped (Figure 8), inner plate
with submarginal setae; outer plate with
inner marginal spine row and submar-
ginal setae; palp 4-articulate, articles 2
and 3 with marginal and submarginal
setae, terminal article one-third the length
of article 3, with apical setae.

Gnathopod | (Figure 9), coxal plate
rhomboidal with distoanterior seta; basis

elongated; article 5 subequal in length to
article 6, posterior margin of article 5
expanded, with marginal and submarginal
setae, some plumose; article 6, anterior
margin setose, palm serrate with marginal
setae, some plumose; dactyl bifurcate
medially and terminally and not reaching
hind margin of article 6. Gnathopod 2
(Figure 9), robust and larger than gnatho-
pod 1; coxa rectangular, distoanterior
corner with single seta; basis with distal
anterior lobe; palm of article 6 with irreg-
ular margin bearing two medial conical
teeth, hind margin demarcated by a tooth
and one bifurcate spine. Pereopods 5
through 7 (Figure 10), bases with poste-
rior, plate-like extensions; pereopods 3
and 4 (Figure 10), anterior margins of
article 6, and pereopods 5 through 7 pos-
terior margins of article 6 with stout setae.
Pleopods | through 3 (Figure 8), long
and slender, peduncles with 2 harpoon-
like coupling hooks, rami with plumose
setae. Peduncles of uropods | and 2 (Fig-
ure 7) lacking interramal spines. Uropod 1
(Figure 7), outer margin of peduncle with
3 spines; outer margin of outer ramus
with 1 medial spine, outer margin of inner
ramus with | medial spine, inner margin
of inner ramus with 4 spines. Uropod 2
(Figure 7), outer margin of outer ramus
with 1 medial spine, outer margin of inner
ramus with | medial spine. Uropod 3
(Figure 7) vestigial, with two marginal
setules. Telson (Figure 7) dorsally pro-
duced and armed with 2 long setae.
Female: 3.2 mm in length. All features
same as male except as follows: gnathopod
1 (Figure 11), article 6, anterior margin
with plumose setae, hind margin and
palm demarcated by a single bifurcate
spine, dactyl terminally bifurcate; gnatho-

16 Postilla 226

The Genus Podocerus
from Guana Island, B.V.I.

Figure 11

Podocerus fissipes, from Guana Island. YPM 24073, female, 3.2 mm. Scale 0.1 mm.

pod 2 (Figure 11), with large oostegite,
article 4 forming a large posterior lobe
with long setae, hind margin of article 6
demarcated by two bifurcate spines, palm
straight.

Remarks. Serejo (1995) provided a list of
the 39 described species in the genus
Podocerus, and mentioned three species
from the coast of Brazil. These are P. fis-
sipes and P. brasiliensis collected in associ-
ation with sponges, and Podocerus fulanus
Barnard 1962 taken from the surface of

intertidal animal colonies. Other than
minute differences in the number of mar-
ginal setae on antenna 2 and the number
of spines on the rami of uropods 1 and 2,
the specimens of P. fissipes from Guana
Island are indistinguishable from P. fis-
sipes in Brazil.

Reanalysis of type material of P. fis-
sipes has revealed discrepancies in the
characters used and illustrated by Serejo
(1995). The flagellum of antenna 2 is 3-
articulate rather than 4-articulate, and
each article of the flagellum has distinct

The Genus Podocerus Postilla 226 17
from Guana Island, B.V.I.

Figure 12

Podocerus fissipes, from Brazil. MNRJ 6431, male, 2.8 mm. Scale: a (A2), 0.1 mm; b (UR, P7),
0.05 mm.

18 Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

Table 2

Morphological variation between Podocerus tachyrheo and P. fissipes.

P. tachyrheo P, fissipes
Type locality Bermuda Brazil

Number of flagellar 5 +
articles on antenna |

Number of spines 2 1
demarcating hind margin

of article 6 of the

male gnathopod 2

Number of marginal spines 4 3
on peduncle of uropod 1

Number of spines 2 1-2
on outer margin of
outer ramus of uropod |

Number of spines 8) 1
on outer margin of
inner ramus of uropod |

Number of spines 6 4
on inner margin of
inner ramus of uropod 1

Number of spines 2 1-2
on outer margin of
outer ramus of uropod 2

Number of spines 3 2-3
on outer margin of
inner ramus of uropod 2

Number of spines 6 3-6
on inner margin of
inner ramus of uropod 2

Number of apical spines on telson 4 2

spines (Figure 12). Unfortunately, only sipes is similar to P. tachyrheo, a species
one specimen with antenna 2 from Brazil | endemic to Bermuda. Reanalysis of type
is available for study. Article 5 of male material of both species has revealed fur-
gnathopod 2 is missing from the illustra-__ ther discrepancies in many of the charac-
tions (Serejo 1995: figs. 1b, 2g, 3a) and ters Serejo (1995) used to differentiate
male gnathopod 1 and 2 are more setose. these species. The primary differentiating
Serejo (1995) mentioned that P. fis- character is “a notch on article 6 of pere-

The Genus Podocerus
from Guana Island, B.V.I.

opods 3-7” that is present in P. fissipes and
not in P. tachyrheo. Superficially this char-
acter appears to be a notch (Figure 12),
but closer examination reveals that the
“notch” is likely a muscle attachment
point for the dactyl within article 6. Fur-
thermore, the bifurcate spines on the
uropods (Figure 12), described as absent
in P. fissipes, are actually present in both
species. However, there are other features
that serve to separate the two species; the
most significant differences are shown in
Table 2.

Summary

Baldinger and Gable (2000) first reported
the presence of Podocerus from Guana
Island, and in the Caribbean P. jareckit
and P. fissipes are currently known from
only Guana Island. The biogeographic
distribution of Podocerus from islands
surrounding Guana and throughout the
Caribbean will not be known until further
studies are completed. The occurrence of
a species from Guana (P. fissipes) that
exists outside the Caribbean suggests that
the amphipod fauna of the Caribbean
may be related to adjacent faunas, such as
those of Bermuda, the Gulf of Mexico,
and the Atlantic coast of South America.

Acknowledgments

A. J. Baldinger is grateful to the Jarecki
family, the owners of Guana Island, for
their dedication to conserving the flora
and fauna of the island, and for affording
him the opportunity to conduct this
study. He also thanks E. A. Lazo-Wasem at
the Peabody Museum of Natural History,
Yale University, for the invitation to assist

Postilla 226 19

him with field collecting, for helpful com-
ments and discussions on amphipod
biogeography, and for reviewing this
manuscript. This paper also benefited
from reviews by C. O. Coleman, Museum
fiir Naturkunde, Berlin, Germany, and R.
Vonk and S. Konenmann, both from the
Zoological Museum, Amsterdam, The
Netherlands. All errors are the sole re-
sponsibility of the authors. We thank

C. Serejo of the Museu Nacional UF Rio
de Janeiro for the loan of P. fissipes, and
A. B. Johnston of the Museum of Com-
parative Zoology, Harvard University, for
sharing a departmental microscope. This
study has been supported in part by a
Museum of Comparative Zoology Bar-
bour Funds grant to A. J. Baldinger, by a
CSU-AAUP grant to M. F. Gable, and by
the Conservation Agency, through grants
from the Falconwood Foundation.

About the Authors

Adam J. Baldinger

Museum of Comparative Zoology
Harvard University

26 Oxford Street

Cambridge, MA 02138-2902 USA
abaldinger@oeb.harvard.edu

Michael F. Gable

Department of Biology

Eastern Connecticut State University
Willimantic, CT 06226-2295 USA
gable@easternct.edu

Curatorial Affiliate

Division of Invertebrate Zoology
Peabody Museum of Natural History

‘ale University

20 Postilla 226 The Genus Podocerus
from Guana Island, B.V.I.

Literature Cited

Baldinger, A. J. 2000. Amphipoda of the Caribbean region and the Gulf of Mexico. Pol.
Arch. Hydrobiol. 47(3—4):697—702.

Baldinger, A. J. and M. F. Gable. 1994. Two new species of Podocerus Leach (Crustacea:
Amphipoda: Podoceridae) from Bermuda. Proc. Biol. Soc. Wash. 107:707—720.

— 1995. The occurrence of amphipods and other peracarid crustaceans in the rocky
littoral zone of Bermuda. Pol. Arch. Hydrobiol. 42(2):431—439.

— 2000. Additional records of Podocerus (Amphipoda: Podoceridae) from the Caribbean
[abstract]. In: 10th International Colloquium on Amphipoda program; 2000 April 16-21;
Heraklion, Crete, Greece. Heraklion, Greece: Institute of Marine Biology of Crete. p. 19.

Barnard, J. L. 1962. Benthic marine Amphipoda of southern California: Families
Aoridae, Photidae, Ischyroceridae, Corophiidae, Podoceridae. Pac. Nat. 3:1—72.

Chevreux, E. and J. de Guerne. 1888 Feb 27. Sur un amphipode nouveau (Cyrtophium
chelonophilum), commensal de Thalassochelys caretta Linné [On a new amphipod
(Cyrtophium chelonophilum), commensal of Thalassochelys caretta Linné|. Comptes
Rendus Hebd. Séances Acad. Sci., Paris. 1888:625—628.

Dana, J. D. 1852. Crustacea, Part 2. In: United States Exploring Expedition, volume 14.
Philadelphia: C. Sherman. pp. 689-1618.

Gable, M. FE. and E. A. Lazo-Wasem. 1990. Lysianassidae (Amphipoda: Lysianassoidea)
of Bermuda. J. Crustac. Biol. 10:721—734.

Gable, M. EF. E. A. Lazo-Wasem and A. J. Baldinger. 1988. A description of the
pigmented and non-stygobiontic females of Podobothrus bermudensis Barnard and
Clark, 1985 (Crustacea: Amphipoda: Dulichiidae). Proc. Biol. Soc. Wash. 101:145—150.

Kunkel, B. W. 1910. The Amphipoda of Bermuda. Trans. Conn. Acad. Arts Sci. 16:1—126.

Lazo-Wasem, E. A., A. J. Baldinger and M. F. Gable. 1989. Pariphinotus Kunkel, 1910,
the senior synonym of Heterophilas Shoemaker, 1933 (Crustacea: Amphipoda:
Philiantidae). Postilla 205:1—5.

Lazo-Wasem, E. A. and M. F. Gable. 1987. A review of recently discovered type
specimens of Bermuda Amphipoda (Crustacea: Peracarida) described by B. W. Kunkel
(1882-1969). Proc. Biol. Soc. Wash. 100:321—336.

—— 1989. First report of a freshwater amphipod (Gammaridea: Hyalellidae), Hyalella
azteca (Saussure), from nonanchihaline waters of Bermuda. Postilla 204:1—4.

Leach, W. E. 1814. Crustaceology. In: David Brewster, editor. The Edinburgh
Encyclopaedia, volume 7. Edinburgh: William Blackwood. pp. 402-403.

Ortiz, M. 1994. Clave grafica para la identificacion de familias y generos de anfipodos
del suborden Gammaridea del Atlantico occidental tropical [Pictorial key to the families
and genera of gammaridean amphipods of the tropical Western Atlantic Ocean]. An.
Inst. Investig. Mar. Punta de Betin 23:59-101.

The Genus Podocerus Postilla 226
from Guana Island, B.V.1.

Ruffo, $. 1987. Contributo alla conoscenza dei Podoceridae Mediterranei. [Contribution
to the knowledge of Mediterranean Podoceridae}. Boll. Mus. Civ. Stor. Nat. Verona
13:1-12.

Ruffo, S., T. Krapp and M. F. Gable. 2000. The genus Maera (Crustacea: Amphipoda:
Melitidae) from Bermuda. Postilla 221:1—35.

Serejo, C. S. 1995. Podocerus fissipes n. sp., a new species of sponge-dwelling amphipod
(Amphipoda, Podoceridae) from the Brazilian coast. Nauplius 3:49—57.
Thomas, J. D. 1993. Identification manual for marine Amphipoda (Gammaridea):

I. Common coral reef and rocky bottom amphipods of south Florida. Tallahassee, FL:
Florida Department of Environmental Protection. 83 pp.

Thomas, J. D. and J. L. Barnard. 1992. Podocerus kleidus, new species from the Florida
Keys (Crustacea, Amphipoda, Dulichiidae). Bull. Mar. Sci. 51:309-314.

SINT

206 5314