aaae sdcrtd ih rnvre eiso titos n er tosie n each on spines two bears and striations of series transverse a with decorated is carapace epibranchial region. Of this group of species, of group this Of region. epibranchial

branchial areas of the carapace. The only published illustration of illustration published only The carapace. the of areas branchial f daig f n ceie o a ye specimen. type a of cheliped one of drawing a of described and has never been illustrated. Neither has been reported from more than a few a than more from reported been has Neither illustrated. neverbeen has and described

ordie r frhr hrceie b te bec o mria siue o te meso- the on spinules marginal of absence the by characterized further are Borradaile

localities. Our studies have revealed that both species are widely distributed on coral reefs coral on distributed widely are species both that revealed have studies Our localities.

occupies the same range. In this paper we redescribe we paper this In range. same the occupies describe the allied species, and present illustrations of each. of illustrations present and species, allied the describe

ntewsenadcnrl aii ca, n htacoey eae u necie form undescribed but related closely a that and Ocean, Pacific central and western the in

nPrelnde fteld-et Pacific. lndo-West the of Porcellanidae on sad n rvddpoorps n h ieclradhbttntsta r nldd in included are that notes habitat and color live the and photographs provided and Islands the account of each species each of account the

Child (CAC) and Jens and (CAC) Child

the Marine Laboratory, University of Guam. of University Laboratory, Marine the

la acc Fo11ndation Hancock Allan

erlshs eldredgei, Petrolisthes

lsl rltd rb (Anomura crabs related closely They differ from other Indo-West Pacific Indo-West other from differ They

sis

Abstract-Petro/is/hes

ahcrpc mri obnd ihuamd eornha margins mesobranchial unarmed with combined margin carapace each

tends to the western Indian Ocean Indian western to the tends

rnh oyei wswr t h oten ain Ilns ad h rne of range the and Islands, Mariana southern the to westward Polynesia French

n eea ld-et aii mmes f h prelnd genus porcellanid the of members Pacific lndo-West several In

h mtra fo nwtk tl, asal sad, ntecletos fC Allan C. of collections the in Islands, Marshall Atoll, Enewetak from material The

aeil rmanme fsucs a xmnd by examined was sources of number a from Material

hsppr sCnrbto No Contribution is paper This

Werding

Department of Zoology, University of Maryland, College Park College Maryland, of University ofZoology, Department

aii, ihRdsrpin fToRltd Species Related Two of Redescription with Pacific,

from the Western Atlantic region and region Atlantic Western the from

W.

bispinos11s

,

University of University

Knudsen

.

.

A New Porcellanid Crab From The Indo-West The From Crab Porcellanid New A :

2 fo teAln acc Fudto adCnrbto N. 3 from 230 No. Contribution and Foundation Hancock Allan the from 429

oclaia) hc ihbtcrl ef i h ld-et Pacific lndo-West the in reefs coral inhabit which Porcellanidae)

.

aeil ad Methods and Materials

Their closest allies are allies closest Their

Borradaile,

Solllhern

O K KROPP K. ROY

(JWK)

Introduction

Petrolisthes

JANET

P.

R

California,

sctd ne Mtra Eaie b station by Examined Material under cited is

decacanth11s

HAIG

P. g/asselli P.

.

P. decacanthus P.

K.

species by having two epibranchial spines on spines epibranchial two having by species

Kropp made collections in the Mariana the in collections made Kropp

P

.

. bispinosus P.

rosariensis

Los Angeles Los

P. decacanthus P.

agfo h atr Pacific. Eastern the from Haig

rmn and Ortmann

,

J.

ayad 04, U.S.A. 20742, Maryland

.

All three species occur from occur species three All agdrn gnrl studies general during Haig

Ortmann and Ortmann

Werding and

,

aiona 08, U.S 90089, California

P. decacanthus P.

P. eldredgei P.

a vr inadequately very was

P

.

and

decacanth11s

P.

Petrolisthes

1

. bispinosus, P.

co/11mbien-

P. bispinosus P.

n. sp. are sp. n.

consists

ex-

.

A.

.

the ,

Los

,

Front trilobate;

.

Merus of chelipeds with

.

Orbits deep; supraocularno spine;

listed).

.

;

Borradaile

2

,

I

.

422 (type locality: Lifu, Loyalty lslands).-

:

Micronesica

Figs

Dactyl of walking legs with four spines on posterior

.

Account of Species

bout as long as broad, or slightly longer

a

Bishop Museum, Honolulu

.

Petro/isthes bispinosus

tubercles

·

Borradaile, 1900

Carapace

:

1981: 39 1981: (Guam, Mariana Islands Front trilobate, median lobe only moderately produced. Two epi-

:

with two strong spineson inner distal margin. Carpus, not including inner

,

et al .• et al

.

Angeles

Washington

AHF-Allan Hancock Foundation, University of Southern California

BMNH-British Museum (Natural History), London BPBM-Bernice P USNM-National Museum of Natural History, Smithsonian Institution CNHM-Natural History Museum, Cambridge University, Cambridge NTM-Northern Territory Museum, Darwin

ZMH-Zoologisches Museum, Hamburg

Depositories of specimens are cited by the following abbreviations:

Kropp,

DIAGNOSIS DESCRIPTION Basal segment of antennules transversely rugose, and with several spines and denticles antennules and of spinestransversely rugose, segment severalwith Basal and

Merus of chelipeds transversely rugose dorsally, with subproximal spine near outer

172

number only; in an appendix at the end of the paper, locality data for these stations are given in full

Petrolisthes bispinosus

median lobe moderately produced beyond laterals; frontal area somewhat deflexed, with

margin. strongest there and on posterior branchial regions, and with anterior margin minutely branchial spines; no supraocular, outer orbital, or hepatic spine small toothor on lowlobe inner margin. Dorsal of surface carpus flattened, without longi- tudinal row of projecting shallowextending mediangroove protogastricto lobes branchial regions; rugae widely set on gastric and anterior branchial regions, usually anteriorly. First movable segment of antennae with spine-tipped lobe on anterior margin; margin; spine frequently present on outer part of distal margin; inner margin with small, outer orbital angle sometimes produced into a small tooth. Hepatic margin unarmed. Two second with small tubercle anteroproximally and sometimes with spinule anterodistally; epibranchial spines. Dorsal surface of carapace with transverse rugae, except on meta- beaded and fringed with fine, closely set setae. marginal teeth, less than twice as long as broad; dorsal surface flattened, with oblique strong, serrated, spine-tipped teeth, one or more of which is occasionally divided into rows of distinct, widely set rugae, their distal margin beaded and fringed with fine setae; triangular, crenulated lobe, this sometimes developed into low tooth; ventral surface third smooth; flagellum non-setose. Outer maxillipeds rugose. toward margininner these rugae broken up tubercles;into flattened inner margin with four faintly rugose two; outer margin rugose, with row of five or six spines including one at distal end; ventral end; at distal one including six fivespines or of row with rugose, margin outer two; ufc wt rnvre ua, hs an roslt poial. amwt biu rugae oblique with Palm proximally. obsolete or faint these rugae, transverse with surface on dorsal surface, these distally beaded and setose as in carpus; rugae broken up into flat- into up broken rugae carpus;in as setose and beaded distally these surface, dorsal on ee tbrls oad ue mri ad n igr; eta srae ih biu rugae. oblique with surface ventral fingers; on and margin outer toward tubercles tened Gape of fingers with trace of pubescence of trace with fingers of Gape

b

I~.....-....

Fig

-

--

-

-·

.

-

;

, aaae n ceies b r b, chelipeds; and carapace a,

ventral and 2 mm 2 and

I.

...

.

Petroli

view;

(c).

s

rhes bispinosusrhes

, , . ih wlig es , 2, I, legs walking right g. f, e,

[Short fringe of setae on rugae of carapace and chelipeds not shown.) not chelipeds and carapace of rugae on setae of fringe [Short

__

_

Borradaile.

o. 0 Dcme 1987 December 20. Vol.

i

ght antennule; c, right 3d maxilliped 3d right c, antennule; ght

_

_

.

b

a,c-g

(Enewetak

and

3

tl, asal Islands Marshall Atoll,

.

cls 3m (, d (a, mm 3 Scales:

;

, ih chel right d,

-

) Im (b), mm I g),

,

JWK

-

407

i

ped

.

) ,

173 .

Setation:

Leg 3 with

1.

1.

2592-01.-Guam, Pago Bay; 3 m, on

of Saipan; 6 May E. P. 1949; Cloud and

surface.

W.

AHF

I~,

Micronesica

USNM 210530.-Guam, Luminao; 6 m, reef front

Borradaile. (Enewctak Atoll, Marshall Islands, coll. C. A

222333.-Guam, Luminao; I m, reef flat on rubble;

Io,

222334.-Lagoon

bispi11osus

USNM

~,

USNM

spines, posterodistal angle usually with very small spine, inner surface

Petrolisthes

~,

9

six

Child.) Scale in millimeters.

60,

Fig. 2.

Abdomenrugose. Telson with seven plates. VARIATIONS: Occasionally VARIATIONS: the rugae on the carpus and palm of the chelipeds are

MATERIAL EXAMINED: Mariana Islands. Saipan; from coral head; 1945; A.H.

First walking leg with merus transversely rugose on outer surface, anterior margin

174

Banner;

merus punctate, anterior margin with three to six spines, posterodistal angle unarmed; 28 Mar. 1980; R. K. Kropp; under rock; 8 Sept. 1980;Tyndzyk; V. Meri with fringe of short plumose setae on anterior margin; all segments with scattered long, non-plumose setae on margins and outer with four to with strong spine ondistal fourth of posterior margin; carpus with anterodistal spine; pro- podus with three movable spinules on posterior margin, in addition to distal pair; dactyl broken over the up entire dorsal surface into flattened, imbricated tubercles. with four movable spinules on posterior margin. Leg 2 with merus transversely rugose, anterior margin with four to six spines, posterodistal angle usually with small spine; car- pus sometimes with anterodistal spine; propodus dactyland armed as inleg party (Loe. D-6); 2

carpus with anterodistal angle unarmed; propodus and dactyl armed as in leg

the chelipeds was said to have a "blunt lobe" on its inner margin. However, one of us us of one However, margin. inner its on lobe" "blunt a have to said was chelipeds the

boulders or on pieces of dead coral rubble. Found in the intertidal rarely and only at very very at only and rarely intertidal the in Found rubble. coral dead of pieces on or boulders

enough to permit positive identification of our material with that taxon, even though though even taxon, that with material our of identification positive permit to enough

distally. distally.

021-69, 021-69,

branchial spines burgundy. Propodus of walking legs dark olive green proximally, then then proximally, green olive dark legs walking of Propodus burgundy. spines branchial

white, marked as marked with light follows brown-orange white,

JWK-407, JWK-407,

time in alcohol); rugae and cristate lateral margins of carapace lined with light blue; epi- blue; light with lined carapace of margins lateral cristate and rugae alcohol); in time no carapace spines other than the two epibranchials were mentioned and the merus of of merus the and mentioned were epibranchials two the than other spines carapace no knobs of coralline algae; 22 Sept. 1953; Bayer team(# 372); l juv., USNM 222337.- USNM juv., l 372); team(# Bayer 1953; Sept. 22 algae; coralline of knobs material from Guam. The overall color of the carapace, chelipeds, and walking legs was was legs walking and chelipeds, carapace, the of color overall The Guam. from material

green with an overlay of many burgundy spots (these often persisting for quite some some quite for persisting often (these spots burgundy many of overlay an with green

lower margin; legs with transverse bands. bands. transverse with legs margin; lower

C. C.

short transverse lines and spots, dactyl with one longitudinal stripe at upper and one at at one and upper at stripe longitudinal one with dactyl spots, and lines transverse short Nielsen; I juv., AHF 2731-01. 2731-01. AHF juv., I Nielsen;

ovigerous females, 3.2 to 7.7 mm. mm. 7.7 to 3.2 females, ovigerous with blue band followed by burgundy band distally; dactyl red proximally, light orange orange light proximally, red dactyl distally; band burgundy by followed band blue with

(Sta. 41); 1 1 41); (Sta.

lines, posterior carapace behind epibranchials with with spots; irregular carpus with of epibranchials behind chelipeds carapace posterior lines, low tides. Not one of the "usual" intertidal species intertidal "usual" the of one Not tides. low

rubble, total depth depth total rubble,

AHF AHF

reef rock; 16 Oct. 1979; R. K. Kropp; Kropp; K. R. 1979; 16 Oct. rock; reef

Id.; outer reef; 7 Aug. 1947; J.P. E. Morrison(# 3168); 3168); Morrison(# E. 1947; J.P. Aug. 7 reef; outer Id.;

under rock, outer reef flat near margin S. of Camel Rock; 3 June 1981; R. K. Kropp; Kropp; K. R. 1981; June 3 Rock; Camel of S. margin near flat reef outer rock, under

Kapingamarangi Atoll, Tewawaelal; outer reef flat, surge zone; 14 July 1954; R. R. Rofen Rofen R. 1954; 14 R. July zone; surge flat, reef Tewawaelal; outer Atoll, Kapingamarangi

126-57); 126-57); lo, lo,

1 1

14 Feb. 1984; J. H. Dominguez; l l Dominguez; H. 1984; J. 14 Feb.

lo, lo,

o, o,

Hand ( # 665); 665); ( Hand #

The specimens from Toguan Bay were quite different in color from the rest of the the of rest the from color in different quite were Bay Toguan from specimens The

REMARKS: The original description of of description original The REMARKS:

BPBM; BPBM;

Society Islands. Moorea, Nuarei Bay; reef; 11 May 1957; Bredin Expedition (Sta. (Sta. Expedition Bredin 1957; May 11 reef; Bay; Nuarei Moorea, Islands. Society

HABITAT: Intertidal to a depth of 6 m. Generally found under small blocks and and blocks small under found Generally m. 6 of depth a to Intertidal HABITAT:

LIVE COLORATION: Carapace, chelipeds, and walking legs reticulated dark olive- dark reticulated legs walking and chelipeds, Carapace, COLORATION: LIVE

USNM USNM

Phoenix Islands. McKean Id.; on SW fringing reef, under rocks; Oct. 1968; P. M. M. P. 1968; Oct. rocks; under reef, fringing SW on Id.; McKean Islands. Phoenix MEASUREMENTS: MEASUREMENTS:

Howland Island Howland

Caroline Islands. lfaluk Atoll, N. end Falarik Id.; outer reef flat, in mostly dead dead mostly in flat, reef outer Id.; Falarik end N. Atoll, lfaluk Islands. Caroline

Marshall Islands. Enewetak Atoll, JWK-56, JWK-56, Atoll, Enewetak Islands. Marshall Loyalty Islands. Lifu, Sandal Bay; 1896-97; A. Willey; 1 1 Willey; A. 1896-97; Bay; Sandal Lifu, Islands. Loyalty Samoa. American Samoa; 1937; 1937; Samoa; American Samoa.

BMNH BMNH

2726-01; JWK-333, JWK-333, 2726-01;

12, 12,

12, 12,

12, 12,

o, o,

222553.-Guam, Toguan Bay;( l m on rubble; reef margin to right of bay; bay; of right to margin reef rubble; on m l Bay;( Toguan 222553.-Guam,

l l

USNM USNM

000000.-Guam, Piti Bay; Bay; Piti 000000.-Guam,

2, 2,

USNM USNM

AHF AHF

12, 12,

USNM USNM

lo, lo,

ca. ca.

. .

222331; CAC 038-69, 038-69, CAC 222331;

USNM USNM

No further locality data; Sept. 1924; "Whippoorwill" Expedition; Expedition; "Whippoorwill" 1924; Sept. data; locality further No

2729-01; JWK-615, JWK-615, 2729-01;

222338.-Tahiti; 1925-26; 1925-26; 222338.-Tahiti;

USNM USNM

1.25 m; outer reef flat near channel; 8 Oct. 1984; R. K. Kropp; Kropp; K. R. 1984; Oct. 8 channel; near flat reef outer m; 1.25

222339. 222339.

Males, 2.6 to 8 to 2.6 Males,

lo, lo,

222335.-Kapingamarangi Atoll, Sokoro; 9 Aug. 1954; 1954; Aug. 9 Sokoro; Atoll, 222335.-Kapingamarangi

222336. 222336.

AHF AHF

Vol. 20. December 1987 1987 December 20. Vol.

2, 2,

2 2

W. W.

juv., USNM 222554. 222554. USNM juv.,

2o, 2o,

2227-01; JWK-396, JWK-396, 2227-01;

Harris; Harris;

.

0 mm; non-ovigerous females, 3.0 to 5.1 mm; mm; 5.1 to 3.0 females, non-ovigerous mm; 0

ca. ca.

lo, lo,

AHF AHF

12, 12,

0.75 m down into sponge-consolidated sponge-consolidated into down m 0.75

: :

Petrolisthes bispinosus bispinosus Petrolisthes

AHF AHF

lo, lo,

Io, Io,

anterior part part anterior of with transverse carapace

USNM USNM

2597-01.-Guam, Piti Bay; intertidal intertidal Bay; Piti 2597-01.-Guam,

. .

C. C.

22, 22,

AHF AHF

2730-01.-Enewetak Atoll, CAC CAC Atoll, 2730-01.-Enewetak

Crossland; Crossland;

Io, Io,

222330.-Bikini Atoll, Namu Namu Atoll, 222330.-Bikini

AHF AHF

2732-01. 2732-01.

USNM USNM

lo, lo,

o o

2525-01; JWK-196, 2 2 JWK-196, 2525-01;

52, 52,

(holotype), (holotype),

22, 22,

222332. 222332.

BMNH. BMNH.

is not detailed detailed not is

AHF AHF

CNHM. CNHM.

2728-01; 2728-01;

175 175 2, 2, .

1981:

et al.,

and the new species

P. decacanthus

Ortmann

Micronesica

Figs. 3, 4

is less closely related to

Petrolisthes decacanthus

Ortmann, 1897; 283, 285, pl. 17 fig. 2 (type locality: Tahiti,

Dactyl of walking legs with three spines on posterior margin

.

Basal segment of antennules with transverse rugae, and with several spines and den-

Merus of chelipedsof Merus transversely rugose dorsally, usually with subproximal spine near

DESCRIPTION: Carapace usually slightly broader than long. Front trilobate, lobes

DIAGNOSIS:trilobate, Front median strongly lobe produced. Supraocular, outer or-

Society lslands).-Laurie, (Praslin Id., 1926: 141 Seychelles).-Haig, 45, 46 1966: Petrolisthes bispinosus (in tokey porcellanids of SW Indian Ocean; nonew records).-Kropp 39 (Guam, Mariana Islands; listed).-Haig, 282 1983: (Seychelles).

Haig) examined Haig) theholotype collections in the the Naturalof History Museum Cam-of

inner andouter margins; innermargin with four strong, serrated, spine-tipped teeth, their

Palm with low, submedian, longitudinal ridge; dorsal surface to inside of this ridge with

inner margin with well developed, crenulated tooth, this tipped with one or two small

dorsal surface flattened, covered with large imbricated tubercles, these beaded on their distal and margin fringed setae; fine tubercleswith frequently replaced bygranules toward

dorsal surface granulate; outer margin with row of seven or eight spines including one at distal end; ventral surfacewith transverse rugae withand inner margin strongly crenulate.

spines; ventral surface rugose or nearly smooth, with two or three strong spines on inner distal margin. Carpus, including not teeth,inner marginal less than twice broad; longas as 176 Rugosities with anterior margin minutely beaded, fringed with fine, closely set setae.

ticles anteriorly. First movable segment of antennae with spine-tipped lobe on anterior margin; second with small tubercle anteroproximally; third smooth; non-setose. flagellum Outer maxillipeds rugose.

outer margin;distal with margin small spine outer near margin and another on outer third;

branchials; elsewhere usually faint, closely set, brokenand up into short transverse lines.

median groove extending to protogastric lobes. Orbits deep; orbital margin armed with

with well developed spine anteriorly, and occasionally with a more posteriorly placed spinule. Two epibranchial spines. Dorsal surface of carapace with transverse rugae, ex-

there and on posterior branchial regions, appearing as granules or short rugae on anterior

with minutely crenulate margins; median lobe strongly produced beyond laterals; distinct Petrolisthes decacanthus distinct supraocular spine; outer orbital angle produced into strong spine. Hepatic margin

frontal region, lack of an outer orbital spine, presence of a small lobe rather than a strong cept on punctate metabranchial regions; rugae widely set on gastric regions, strongest bital, hepatic, and two epibranchial spines present. Merus of chelipeds with well devel- oped tooth on inner margin. Dorsal surface of carpus flattened, without longitudinal row of projecting tubercles

tooth on the merus of the chelipeds, and possession of four movable spinules, instead of three, on the posterior margin of the dactyl of the walking legs.

(J. bridge University and confirmed the identity of our specimens to Borradaile's species.

than the latter two are to each other. differs It them from in its smaller size, less produced F

i

g

.

b, anterior part of carapace; c carapace; of part anterior b,

shown 3. anr , grmdure, aa sad, Sta Islands, Palau reef, Ngaremediu b, Banner;

ventral view; f, g, h, left walking legs I, 2, and 3 and 2, I, legs walking left h, g, f, view; ventral

I mm (c), and 2 mm (d) mm 2 and (c), mm I

Petrolisthes

.

]

decacanthus

.

Sotfig fsteo ua fcrpc adceies not chelipeds and carapace of rugae on setae of fringe [Short

Vol. 20 Vol.

,

rmn. a c (a, Ortmann.

right antennule right

.

eebr 1987 December

-

;

h

d

.

,

,

111

right 3d maxilliped 3d right

Sa

.

i -

Scales: 4 mm (a, e-h), 3 mm (b), mm 3 e-h), (a, mm 4 Scales:

a, Marian pan,

1172.) a, carapace and cheliped and carapace 1172.) a,

__ c ____

_ d ___

a

sad, ol A coll. Islands,

;

e, right cheliped, right e,

a,b,e-h

.

H

C

s;

.

177 .

A

C.

Micronesica

Ortmann. (Enewelak Aloll, Marshall Islands, coll.

decacanthus

) Scale in millimeters.

.

Petrolisthes

.

Child

Fig. 4

First walking leg with merus transversely rugose on outer surface, anterior margin

178

fringed with fine, closely set setae; carpi with tufts of short plumose setae near anterior with five to eight spines, a distinct posterodistal spine, inner surface with strong spine

with three movable spinules on posterior margin in addition to distal pair; dactyl with flattened imbricated tubercles or small, widely set granules; surface to outside of ridge, and surface of fixed finger, with small, widely spaced granules; surface of dactyl with rior margin with five to seven spines, a distinct posterodistal spine; carpus with antero- longitudinal row of flattened imbricated tubercles; ventral surface of chela with oblique dactyl propodusdistal spine; and armed as leg in l. Leg with 3 merus transversely rugose, rugae, these strongly beaded on edge, and sometimes broken up outer toward margin and anterior spines,margin or with four five posterior margin unarmed or with minute spinule distally; carpus unarmed anterodistally; propodus and dactyl armed as in leg I. Setation: pubescence. Meri with dense fringe of short plumose setae on anterior margin, rugae of outer surface

(rarely on two) distal fourth of posterior margin; carpus with anterodistal spine; propodus

three movable spinules on posterior margin. Leg 2 with merus transversely rugose, ante-

on fixed finger into small groups of widely set granules. Gape of fingers with trace of Vol. 20. December 1987 179 margin; carpi, propodi, and dactyli with scattered long, non-plumose setae on margins and outer surface. Abdomen smooth; dorsally visible articles occasionally with a transverse groove. Telson with seven plates. VARIATIONS:In some of our material the hepatic spine is as large as, or larger than, the outer orbital spine and the two extend to about an equal distance anteriorly, giving the appearance of a bispinate outer orbital angle (fig. 3b). This condition occurs in our specimens from the Glorioso Islands, West Coral Sea, and Samoa, and in part of the material from the Palau Islands and Enewetak Atoll, as well as in several individuals from the Seychelles (Haig, 1983). It appears to be a function of size, since it was observed in specimens with the carapace length 3.2 to 6.2 mm in males, 4.6 to 5.8 mm in non- ovigerous females, 4.4 to 7.5 mm in ovigerous females, and to 4.3 mm in juveniles; whereas specimens with a "typical" hepatic spine measure 6.0 to 12.2 mm in males, 5.2 to 11.1 mm in non-ovigerous females, and 9.2 to 12.8 mm in ovigerous females. In a 3.0 mm specimen from Pago Bay, Guam, there is no outer orbital spine and the hepatic spine is very small. MATERIAL EXAMINED: Glorioso Islands. Grande Glorieuse; intertidal zone; 30 Jan. 1971; A. Crosnier; 2 2 , AHF 2734-0 I . Maldive Islands. Gan Id.; 25 Aug. 1964; P. Davis; 12, BMNH 1966:2:1:23. Palau Islands. E. side of Urukthapel, Ngaremediu reef, 7°l3'09"N, 134°26'40"E; reef flat; 19 Aug. 1955; Bayer team (Sta. 111-1172); Io, I 2, USNM 222341.-No further locality data; 19 Nov. 1908; C. Grethe; 12, ZMH. Mariana Islands. Saipan; from coral head; 1945; A.H. Banner; 12, USNM 222343.-Guam, Togcha Bay; reef flat, tidepool; 23 Sept. 1967; R. S. Jones; Io, AHF 2586-02.-Guam, Pago Bay; 3 m, reef front on coralline algae and rubble; 16 Oct. 1979; R. K. Kropp; Io, I 2 , USNM 2 !0534. Caroline Islands. Yap, NE side; from coral head on sand flat; 1950; R. W. Hiatt (# Y-249N); I 2, USNM 222342.-Kapingamarangi Atoll, Tewawaelal; outer reef flat, surge zone; 14 July 1954; R.R. Rofen (Sta. 41); I 2, USNM 222340. West Coral Sea. Marion Reef, south cay, l9°17'S, 152°13'E; reef flat at low water; 12 May 1979; N. L. Bruce, RIV "Lady Basten" (Sta. LB-IO); I 2, NTM. Marshall Islands. Enewetak Atoll; no further data; J. W. Knudsen; I 2, AHF 2733- 01.-Enewetak Atoll, JWK-396; Io, 3 2, AHF2728-02.-EnewetakAtoll, CAC021-69, 2o, 22, USNM 222344; CAC 038-69, 120,162, 2juv., USNM 222321. Samoa. American Samoa; 1937; W. Harris; I 2, AHF 2732-02. MEASUREMENTS: Males, 3.0 to 12.2 mm; non-ovigerous females, 4.6 to I I. I mm; ovigerous females, 4.4 to 12.8 mm; juveniles, 4.1 and 4.3 mm. LIVE COLORATION: No information is available. HABITAT: Subtidal to 3 m; on large blocks of reef rock having many crevices among them, or on coralline algae. REMARKS:Several years ago J. Haig examined six syntypes of this species, which are housed in the Academy of Natural Sciences of Philadelphia. They proved to be badly fragmented and quite useless for purposes of identification- an observation recently con- firmed for us by R. H. Gore. Fortunately, however, the species can be recognized from the 180 Micronesica original description (Ortmann, 1897: 285-6). In particular, Ortmann mentioned the supraocular spine, the spiniform outer orbital angle, a spine behind the latter and anterior to the cervical groove (i.e. the hepatic spine), and two epibranchial spines behind the cer- vical groove. In a key to several species of Petrolisthes with rugose carapaces (p. 283), Ortmann erroneously stated that P. decacanthus has two spines on the posterior side of the carapace in addition to the epibranchials ("Zwei Epibranchialdornchen auf jeder Seite. Ferner stehen an der hintern Seite 2 Dornchen"). It is unlikely that he was referring to spines on the lateral carapace margin behind (i.e. posterior to) the epibranchials, because no such spines were mentioned in the description. Probably "hintern Seite" was a lapsus on the part of the author, and he meant the two spines (outer orbital and hepatic) on the anterior part of the lateral margin.

Petrolisthes eldredgei, n. sp. Figs. 5, 6 Petrolisthes n. sp. 4. - Kropp et al., 1981: 39 (Guam, Mariana Islands; Iisted).-Kropp and Eldredge, 1982: 125 (Guam, Mariana Islands; listed). DIAGNOSIS: Front trilobate, median lobe strongly produced. Outer orbital and two epibranchial spines; no supraocular or hepatic spine. Merus of chelipeds with well devel- oped tooth on inner margin. Dorsal surface of carpus with longitudinal row of prominent, projecting tubercles. Dactyl of walking legs with three spines on posterior margin. DESCRIPTION: Carapace usually slightly broader than long. Front trilobate; me- dian lobe strongly produced beyond laterals; distinct median groove extending to proto- gastric lobes. Orbits deep; no supraocular spine on orbital margin; outer orbital angle produced, usually into strong spine. Hepatic margin unarmed. Two epibranchial spines. Dorsal surface of carapace with transverse rugae; these widely set on gastric regions, else- where closer together; broken up into transversely elongate tubercles on anterior branchial regions, fainter and appearing as rows of small flattened granules on frontal and meta- branchial regions, elsewhere forming distinct transverse lines interrupted only at grooves separating regions. Anterior margin of rugae minutely beaded, and fringed with fine, closely set setae. Basal segment of antennules transversely rugose, and with several spines and den- ticles anteriorly. First movable segment of antennae with spine-tipped lobe on anterior margin; second with small tubercle or blunt spine anteroproximally; third smooth; flagel- lum non-setose. Outer maxillipeds rugose. Merus of chelipeds transversely rugose dorsally, usually with subproximal spine near outer margin; distal margin with one or two spines on outer third; inner margin with strong, crenulated tooth; ventral surface rugose, with two or three prominent spines on inner distal margin. Carpus, not including inner marginal teeth, less than twice as long as broad; dorsal surface with median longitudinal row of prominent tubercles, these strongly raised and beaded at their distal end; elongate rugae, widely set granules, or small imbri- cated tubercles to outside of this row, and small, widely set granules and a few tubercles to inside; inner margin with four strong, serrated, spine-tipped teeth, their dorsal surface granulate; outer margin with row of six or seven spines including one at distal end; ventral

______

Fig. 5. 5. Fig.

shown.] shown.]

cheliped, ventral view; e, f, g, right walking legs 1, 2, and 3. Scales: 4 4 Scales: 3. and 2, 1, legs walking right g, f, e, view; ventral cheliped,

038-69.) a, carapace and chelipeds; b, right antennule; c, right 3d maxilliped; maxilliped; 3d right c, antennule; right b, chelipeds; and carapace a, 038-69.)

I mm (b), (b), mm I

b b

C C

a,d-g a,d-g

Petrolisthes eldredgei, eldredgei, Petrolisthes

and 2 2 and

mm (c). [Short fringe of setae setae of fringe [Short (c). mm

Vol. 20 Vol.

new new

species. species.

. .

December 1987 1987 December

(Enewetak Atoll, Marshall Marshall Atoll, (Enewetak

on on

rugae of carapace carapace of rugae

and chelipeds not not chelipeds and

Islands, CAC CAC Islands,

mm (a, d-g), d-g), (a, mm

d, right right d, 181 181

islands, islands,

Marshall Marshall

Enewctak Enewctak Atoll,

. .

posterodistal posterodistal angle with two or three

, ,

Micronesica Micronesica

new new species. (Holotype

eldredgei, eldredgei,

A. A. Child.) Scale millimeters. in

. .

C

Petrolistlres Petrolistlres

coll. coll.

Fig. Fig. 6.

All All walking legs with merus transversely rugose on outer surface, that of leg I with

spines; spines; carpus with anterodistal propodus spine; dactyl and armed as in leg I. of Merus leg

leg leg 2 with three to five spines on anterior margin

in addition to distal pair; dactyl dactyl addition distal three in pair; to movable with spinules on posterior margin. Merus of

spine spine on distal fourth of posterior margin, this sometimes lacking in small specimens;

four four to six spines on anterior margin, two posterodistal spines, inner surface with strong

carpus carpus with anterodistal spine; propodus with three movable spinules on posterior margin

Gape Gape of fingers frequently with trace of pubescence.

beaded beaded on their free (distal) edge. Dorsal surface chelipeds of with very short, pubes- fine

marginal marginal granules; ventral surface of chela with prominent oblique rugae, these strongly

cence, cence, this developed into short tufts of plumose setae on margins of merus and carpus.

smooth, smooth, longitudinal groove to outside, latter defined on its outer side by double row of

latter latter also occurring on fixed outer finger; margin, including that of fixed finger, strongly

beaded beaded on their distal edge; smaller, raised granules to inside of this row and deep,

crenulate; crenulate; surface of dactyl with row of raised or flattened imbricated tubercles, these

median median longitudinal ridge, latter frequently of with row prominent, strongly projecting tu-

surface surface with transverse rugae, inner margin distinctly crenulate. Palm with low, sub-

bercles; bercles; surface on both sides of this ridge with small, widely separated, raised granules, 182 182

presence of a row of strong tubercles on the carpus of the chelipeds, this species can be be can species this chelipeds, the of carpus the on tubercles strong of row a of presence

vgru fmls 5 females, ovigerous

porcellanids, porcellanids,

similar algal structures at some other reef margins. The species occurs with two other other two with occurs species The margins. reef other some at structures algal similar

JWK-411, JWK-411, h hlpd i h akfr r rdmnnl dr re u aesm e, particu- red, some have but green dark predominantly are form dark the in chelipeds The

of the consolidated coralline algae crust at the seaward edge of erosion benches, or among among or benches, erosion of edge seaward the at crust algae coralline consolidated the of

(Sta. 0902-EI); 0902-EI); (Sta. areas on the carapace, but the overall hue of the carapace of the dark form is dark green dark is form dark the of carapace the of hue overall the but carapace, the on areas

found in the same habitats. habitats. same the in found

Atoll, Nado Id.; 1951-52; S. S. 1951-52; Id.; Nado Atoll, ih oe ih rdo rie areas raised on red light some with

222325; 222325;

larly on the tubercles and other raised areas. The chelae of the light form are mainly white white mainly are form light the of chelae The areas. raised other and tubercles the on larly

consolidated coralline algae at seaward edge of erosion bench; 11 Aug. and 3 Sept. 1984; 1984; Sept. 3 and 11 Aug. bench; erosion of edge seaward at algae coralline consolidated

near lithothamnion ridge; 9 July 1952; J.P. E. Morrison(# 1904); 1904); Morrison(# E. J.P. 1952; July 9 ridge; lithothamnion near

CAC 038-69). 038-69). CAC

USNM 222328. 222328. USNM

R. K R.

R

Marshall Islands; IO Oct. 1969; 1969; IO Oct. Islands; Marshall

Bay, shelf under Guam Memorial Hospital; Flora and Fauna class, University of Guam; Guam; of University class, Fauna and Flora Hospital; Memorial Guam under shelf Bay, with fringe of long setae on outer margins. Telson with seven plates seven with Telson margins. outer on setae long of fringe with

line algae; 29 July 1980; R. K. Kropp; Kropp; K. R. 1980; July 29 algae; line

spinule, but never with a distinct supraocular spine as in in as spine supraocular a with never distinct but spinule,

ou addcy amd si e l leg in as armed dactyl and podus

ing leg l is missing or obsolescent. obsolescent. or missing is l leg ing

in large specimens, the subdistal spine on the inner posterior margin of the merus of walk- of merus the of margin posterior inner the on spine subdistal the specimens, in large

non-plumose setae on outer surface and posterior margin; propodi and dactyli with long, long, with dactyli and propodi margin; posterior and surface outer on setae non-plumose

plumose setae on anterior margin, these setae concealing spines, and with tufts of long, long, of tufts with and spines, concealing setae these margin, anterior on setae plumose

two small spines; carpus usually unarmed anterodistally, rarely with very small spine; pro- spine; small very with rarely anterodistally, unarmed usually carpus spines; small two

3 with two or three spines on anterior margin, posterodistal angle unarmed or with one or or one with or unarmed angle posterodistal margin, anterior on spines three or two with 3 non-plumose setae on margins and outer surface. surface. outer and margins on setae non-plumose

12, 12,

. .

K

umt Acieao Rri Aol nrh n Nauaa Id Ngarumaoa end north Atoll, Raroia Archipelago. Tuamotu

REMARKS: In addition to the absence of a supraocular and hepatic spine and the the and spine hepatic and supraocular a of absence the to addition In REMARKS:

HABITAT: Found by R. K. Kropp only among the numerous crevices and crannies crannies and crevices numerous the among only Kropp K. R. by Found HABITAT: Society Islands. Tahiti; 1925-26; 1925-26; Tahiti; Islands. Society

IECLRTO:Tee r w itntclr forms color distinct two are There COLORATION: LIVE asal sad. nwtk tl, nwtk d; ef 2 et 16; A 1968; Sept. 2 reef; Id.; Enewetak Atoll, Enewetak Islands. Marshall

MEASUREMENTS: Males, 3.5 to IO. I mm; non-ovigerous females, 5.3 to 9.6 mm; mm; 9.6 to 5.3 females, IO. non-ovigerous to mm; I 3.5 Males, MEASUREMENTS:

AHF AHF

. .

PARATYPES

. .

HOLOTYPE: HOLOTYPE:

Abdomen rugose; striae of dorsally visible articles densely setose, and all articles articles all and setose, densely articles visible dorsally of striae rugose; Abdomen

VARIATIONS: In occasional individuals the orbital margin is armed with a minute minute a with armed is margin orbital the individuals occasional VARIATIONS: In

Kropp; Kropp;

Kropp; Kropp;

lo lo

2685-01.-Guam, Piti Bay; 0 m, outer reef flat at reef margin; 3 June 1981; 1981; June 3 margin; reef at flat reef outer m, 0 Bay; Piti 2685-01.-Guam,

12, 12,

(illustrated (illustrated

Pachycheles pisoides pisoides Pachycheles

lo, lo,

3o, 3o,

AHF AHF

lo

: :

32

o o

Mariana Islands Mariana

2 2

, ,

.

2681-01.-Enewetak Atoll, CAC 038-69, 038-69, CAC Atoll, 2681-01.-Enewetak

3 to 8.1 mm;juveniles, 1.9 to 3.5 mm. mm. 3.5 to 1.9 mm;juveniles, 8.1 to 3

2, 2,

AHF AHF

(CL (CL

, ,

PM 5I0625 BPBM

specimen), USNM 222326; 222326; USNM specimen),

USNM USNM

2683-01.-Enewetak Atoll, JWK-383, JWK-383, Atoll, 2683-01.-Enewetak

O mm) IO. I

F. F.

MacNeil (Sta. 827); 827); (Sta. MacNeil

222555.-Guam; 1945; D. M. Johnson; Johnson; M. D. 1945; 222555.-Guam;

C. C.

Vol. 20 Vol.

(Heller) and and (Heller)

. .

. .

. .

A

um Lmno efmri ncnoiae coral- consolidated on margin reef Luminao; Guam,

Many variations of the two forms exist and can be be can and exist forms two the of variations Many

Setation: Meri and carpi with dense fringe of short short of fringe dense with carpi and Meri Setation:

, ,

. .

C. C.

USNM 216664; Enewetak Id., Enewetak Atoll, Atoll, Enewetak Id., Enewetak 216664; USNM

.

hl, nwtk tl Dvn Epdto (Sta Expedition Diving Atoll Enewetak Child,

-Guam, Pago Bay, Taogam Point; 0 m, from from m, 0 Point; Taogam Bay, Pago -Guam,

. .

December 1987 1987 December

Crossland; Crossland;

lo, lo,

2 2

Petrolisthes elegans elegans Petrolisthes

juv

.

lo, lo,

Io, Io,

, AHF 2098-01.-Guam, Agana Agana 2098-01.-Guam, AHF ,

lo, lo,

Petrolisthes decacanthus. decacanthus. Petrolisthes

BMNH BMNH

USNM USNM

I I

2, 2,

. .

Both have red and white white and red have Both

AHF AHF

2o, 2o,

222327. 222327.

1982:589. 1982:589.

.; .;

12, 12,

. .

12, 12,

Haig. Haig.

5 5

from holes in reef reef in holes from

2684-01.-Likiep 2684-01.-Likiep

2, 2,

USNM USNM

AHF AHF

2 2

juv

lo, lo,

.

. .

2682-01; 2682-01;

, USNM USNM ,

222329. 222329.

Havens Havens

Rarely, Rarely,

I I

juv., juv.,

183 183

. . . . 184 Micronesica distinguished from the closely related P. decacanthus by details in the rugosities and granulations of the pereopods, and by the heavier setation of the walking legs. DERIVATION OF NAME: For Dr. Lucius G. Eldredge, in recognition of his contri- butions to the knowledge of the marine fauna of the lndo-West Pacific.

Discussion Petrolisthes bispinosus, P. decacanthus, and P. eldredgei inhabit coral reefs in the central and western Pacific Ocean, from French Polynesia westward to the southern Mariana Is- lands. The geographical distribution of P. decacanthus also includes the Maldive Islands and westward nearly to the east coast of Africa, but it has not yet been reported from such intervening areas as Australia, the East Indian Archipelago, and the eastern Indian Ocean. In the Pacific Ocean two, or all three, species have occasionally been collected at the same locality. Alone among lndo-West Pacific members of genus Petrolisthes with transversely striate carapaces, these three species are characterized by having two epibranchial spines on each side of the carapace, in combination with unarmed mesobranchial margins and the presence of a strong spine on the inner posterior margin of the merus of the first walk- ing leg. Thus, as a group they stand out quite distinctly from their lndo-West Pacific con- geners. Their closest relatives are to be found in the New World, where another three coral reef species have strongly rugose carapaces with two epibranchial spines on each side and unarmed mesobranchials. Petrolisthes glasselli Haig, 1957 inhabits the eastern Pacific from Mexico to Colombia, and oceanic islands including Clipperton and the Galapagos. P. rosariensis Werding, 1978 and P. columbiensis Werding, 1983 are known only from the Caribbean coast of Colombia. Several characters of Petrolisthes glasselli, P. rosariensis and P. columbiensis have recently been compared by Werding ( 1983: 408). However, he did not mention the arma- ture of the inner posterior margin of the merus of walking leg l . An examination of mate- rial of P. glasselli in the collections of the Allan Hancock Foundation showed that, unlike the three related Indo-West Pacific species, it lacks a spine in this position. Of eight type specimens of P. rosariensis in the AHF collections which were examined for this charac- ter, two have a strong spine, three a very small or obsolescent spine, and the rest none. We have not been able to examine material of P. columbiensis.

ACKNOWLEDGMENTS The first author acknowledges the help of several persons who made this study possible: J. W. Knudsen, A. Havens, and C. A. Child for permission to report on their Enewetak collections; C. B. Goodhart for providing access to the Crustacea collections of the University Museum of Zoology, Cambridge University, and for other courtesies ex- tended on that occasion; C. A. Child (USNM), A. J. Bruce (NTM), and P. Clark (BMNH) for the loan of specimens; and R.H. Gore for information on the types of Petrolisthes decacanthus. She also acknowledges past help by the late A. Panning (ZMH) and D. M. Devaney (BPBM) who lent material and provided considerable information. Preliminary work by J. Haig on the USNM porcellanid collections was supported in part by AEC Con- Vol. 20. December 1987 185 tract AT(30-l)2409 with the Smithsonian Institution; thanks are due to F. A. Chace, Jr. for making this material available. An AEC grant administered by the University of Ha- waii supported C. A. Child's field work at Enewetak. General studies by J. Haig on lndo- West Pacific Porcellanidae, part of which were used in the present paper, were supported by Grant GB-3225 from the National Science Foundation. The second author is indebted to L. G. Eldredge and the University of Guam Marine Laboratory for help and support during his research and collecting activities in the years 1979 to 1984. A grant to G. J. Vermeij by the Biological Oceanography Program of the National Science Foundation provided further support. Jane H. Dominguez assisted with collecting in Guam during 1984. We thank J. S. Garth and R. H. Gore for reading a draft of the manuscript and providing helpful suggestions, and Frances Runyan for preparing the drawings.

References Cited

Borradailc, L.A. 1900. On the Stomatopoda and Macrura brought by Dr Willey from the South Seas. Pp. 395- 428, pis. 36- 39 in A. Willey (ed.), Zoological results based on material from New Britain, New Guinea, Loyalty Islands and elsewhere, collected during the years 1895, 1896 and 1897. Part IV. Univer- sity Press, Cambridge. Haig, J. 1966. Sur une collection de Crustaces Porcellanes (Anomura: Porcel/anidae) de Madagascar et des Comores. Cah. ORSTOM, Oceanogr. 3: 39-50. 1983. Porcellanidae (Decapoda, Anomura) from the Seychelles, western Indian Ocean. Crusta- ceana 45: 279- 289. Kropp, R. K., and L. G . Eldredge. 1982. Macroinvertebrates. Pp. 107- 131 in R.H. Randall and L. G. Eldredge (eds.), Assessment of the shoalwater environments in the vicinity of the proposed OTEC devel- opment at Cabras Island, Guam. Univ. Guam Mar. Lab. Tech. Rpt. 79. Kropp, R. K., D.S. Wooster, and L. G. Eldredge. 1981. Preliminary checklist of anomuran crustaceans from Guam. Pp. 39- 41 in A working list of marine organisms from Guam. Univ. Guam Mar. Lab. Tech. Rpt. 70. Laurie, R. D. 1926. Anomura collected by Mr J. Stanley Gardiner in the western Indian Ocean in H.M.S. "Sealark." Trans. Linn. Soc. Lond. (2, Zoo!.) 19: 121-167, pis. 8-9. Ortmann, A. 1897. Carcinologische Studien. Zoo!. Jb., System. 10: 258- 372, pl. 17. Werding, 8. 1983. Der Petrolisthes ga/athim,s-Artenkomplex im karibischen Raum mit Beschreibung von P. caribensis n. sp. und P. columbiensis n. sp. (Crustacea: Anomura: Porcellanidae). Senckenberg. Biol. 63: 407-418.

APPENDIX Collecting data from Enewetak Atoll, Marshall Islands CAC.-Collections of C. Allan Child, Enewetak Diving Expedition. 021-69. Enewetak Id., outer reef rim and surge channels along northern 1/3 of is- land; 2-3 ft., lithothamnion reef flat and ridge; 27 Sept. 1969; C. A. Dawson and C. A. Child. Petrolisthes bispinosus, P. decacanthus. 038-69. Enewetak Id., ocean side, surge channel and blow hole about 20 ft. back from outer reef edge, ca. 200 ft. north of runway and JOOft. out from beach; 0-2 ft. at blow hole; JOOct. 1969; C. A. Child. The whole small surge channel was poisoned and the results were carried up by incoming tide to rear of channel and out through blow hole onto reef flat to be scooped up. Petrolisthes bispinosus, P. decacanthus, P. eldredgei. ;

Petro-

removed

Pocillopora elegans

Petrolisthes bispinosus.

.

.

Knudsen

Petrolisthes bispinosus.

.

W.

J.

Micronesica

Petrolisthes eldredgei.

, west end, seaward reef; crabs cracked from corals

.

Knudsen.

Petrolisthes bispinosus.

J. W. Knudsen.

Petrolisthes bispinosus, P. decacanthus.

;

W.

Petrolisthes bispinosus

.

, study site; crabs from dead and algal encrusted coral on the algal

.

Petrolisthes bispinosus

.

, algal ridge; crabs from corals; 9 Aug. J. W. 1967;Knudsen.

.

Knudsen.

W.

specimens from live and dead encrusted

;

J.

Tim Smith

;

;

Knudsen

W.

196. Enewetak Id. on outer reef, study site between Enewetak and Bokandretok

56. Enewetak Id., north end, seaward reef flat; crabs from under rocks and/or dead

383. Enewetak Id

333. Bokandretok [Sand] Id., study site; collections made on algal ridge by cracking 396. Enewetak Id., study site; crabs removed at random along the entire algal ridge;

411. Engebi Id

615. Muti [Japtan] Id.; random collecting on the algal ridge north of island; 28 Aug. 407. Mui [Buganegan] Id

Aug. J. 1967;Knudsen. W.

186

1968; J. 1968;

and live coral; Mar. 16 1965

JWK.-Collections of Jens

[Sand] Islands

from inside of algal ridge; Aug. 14 1966;

8 Aug. 1967 ridge; 4 Aug. J. W. 1967;Knudsen. lisrhes eldredgei. 5 22 July 1967

overgrown encrusting corals which harbored many crabs in the numerous larger burrows;