Paragiopagurus bicarinatus ( De (De Saint Laurent, 1972)

Lemaitre, R., 1996, Hermit crabs of the family Parapaguridae (Crustacea: Decapoda: Anomura) from Australia: species of Strobopagurus Lemaitre, 1989, Sympagurus Smith, 1883 and two new genera., Records of the Australian Museum 48 (2), pp. 163-221 : 214-217

Paragiopagurus bicarinatus ( De Saint Laurent, 1972)

Fig. 27

Parapagurus acutus bicarinatus De Saint Laurent, 1972: 113 (type locality: Philippines, Albatross sta. 5289).

Sympagurus acutus bicarinatus .- Lemaitre, 1989: 37.­ Lemaitre, 1994: 412.

Holotype. Male (SL 5.6 mm), Philippines, southern Luzon, 5 mi (9.2 km) NW Matocot Point, Albatross sta. 5289, 13°4l'50"N, 120058'03''E, 315 m, 22 Jul 1908, USNM 168310.

Australian material. NORTHERN TERRITORY: 3 males (SL 4.8- 5.8 mm), NW of Collier Bay, FRV Soela, 14°16.5'S, 122°36.6'E, 302 m, 14 Feb 1984, coIl. S. Slack-Smith, WAM.

QUEENSLAND: 1 male (SL 4.1 mm), off Tully, 16° 5l. 8' S, 147°08'E, epibenthic sledge, ORV Franklin, 500 m, 16 May 1986, coli. JCU, QM.

Other material. (For meaning of asterisks see Materials and Methods). SOUTH CHINA SEA: 2 males (SL 4.6, 5.2 mm), near Hong Kong, Albatross sta. 53l3, 21°30'N, 116°43'E, 274 m, 4 Nov 1908, USNM 168982*.

PHILIPPINES: 7 males (SL 3.1-4.9 mm), 1 female (SL 2.9 mm), Verde Is. Passage, off Matocot Point, Albatross sta. 5268, 13°42'N, 120057'15''E, 311 m, 8 JUll 1908, USNM 168981*. 1 male (SL 3.9 mm), between Leyte and Mindanao, off Botoselo Point, Albatross sta. 5486, lOo02'N, 125°19'20"E, 314 m, 22 Jul 1908, 1070 m, USNM 168983*.

Diagnosis. Phyllobranchiate gills. Shield ( Fig. 27a ) as long as broad; dorsal surface weakly calcified medially; rostrum broadly rounded, with low dorsal ridge; anterior margins weakly concave; lateral projections subtriangular, terminating in small spine; ventrolateral margin with spine (not always visible in dorsal view); posterior margin broadly rounded. Ocular peduncles more than half length of shield; ocular acicles subtriangular, terminating in strong multifid spine; corneae slightly dilated. Maxillule with internal lobe of endopod bearing 4 long seta. Sternite of 3rd maxillipeds with small spine on each side of midline. Epistomial spine straight. Antennular peduncle exceeding distal margin of corneae by 0.75 length of ultimate segment. Antennal peduncle ( Fig. 27b ) reaching distal margin of cornea; 2nd segment with dorsolateral distal angle produced, terminating in strong simple spine reaching to midpoint of antennal acicle; acicles reaching distal margin of corneae, mesial margin with 10 to 13 spines; flagellum with short and long setae <1 to 4 flagellar articles in length respectively. Chelipeds markedly dissimilar, with moderately dense setae. Right cheliped ( Fig. 27d,e ) with palm broader than long, fingers curved ventromesially, dactyl with concave ventromesial face; dorsal face of palm with numerous small spines or tubercles, ventral face smooth or with scattered small tubercles; palm with dorsolateral, dorsomesial, and ventromesial margins each well delimited by row of strong spines, and ventromesial face expanded distally; carpus with numerous small tubercles or spines on dorsal surface, and well delimited dorsolateral margin with row of spines. Left cheliped ( Fig. 27d ) with lateral face of carpus usually weakly calcified; carpus with dorsal row of 6 to 15 small spines, and strong dorsodistal spine. Ambulatory legs ( Fig. 27 f-h) with dactyls having ventromesial row of 3 or 4 small corneous spines, and dorsal and dorsomesial rows of long setae; carpi each with small dorsodistal spine; carpus of 2nd pereopod with 2 small dorsal spines (spines sometimes obsolete). Anterior lobe of sternite of 3rd pereopods setose, armed with I marginal spine. Fourth pereopod ( Fig. 27i ) with propodal rasp consisting of 1 row of ovate scales. Vropods and telson ( Fig. 27k ) markedly asymmetrical; telson lacking transverse suture separating anterior and posterior lobes; posterior lobes separated by shallow V-shaped median cleft, terminal margins armed with often long, curved corneous spines. Males lacking Ist gonopods, with unpaired, uniramous 2nd left pleopod ( Fig. 27j ). Female with vestigial right 2nd pleopod.

Habitat and symbiotic associations. Found in gastropod shells.

Distribution. Western Pacific: Philippines, and Australia. Depth: 274 to lO 70 m.

Affinities. Paragiopagurus bicarinatus closely resembles P acutus and P hirsutus . In the former, the mesial face of the right palm is expanded distally, and has a dorsomesial and a ventromesial row of spines. In both P acutus and P hirsutus the mesial face is not expanded distally, and the ventromesial face is rounded and lacks a row of spines.

Remarks. As previously mentioned, Sympagurus acutus bicarinatus (De Saint Laurent, 1972) , is herein elevated to specific rank (see remarks under Paragiopagurus acutus ).

Figures

Fig. 27. Paragiopagurus bicarinatus (De Saint Laurent, 1972), male (SL 4.1 mm), Queensland, QM. a, shield and cephalic appendages; b, right antennal peduncle, lateral; c, left cheliped, dorsolateral; d, right cheliped; e, chela of same, mesial; f, right 2nd pereopod, lateral; g, dactyl of same, mesial; h, right 3rd pereopod, lateral; i, propodus and dactyl of left 4th pereopod, lateral; j, left 2nd pleopod, lateral; k, telson. Scales = 1 mm (a, c-h), and 0.5 mm (b,i-k).