Sympagurus soela, Lemaitre, 1996

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 : 186-190

Sympagurus soela n.sp.

13, 14a

Sympagurus affinis .- Lemaitre, 1994: 381 (in part) (Not Sympagurus affinis [ Henderson, 1888]). (See remarks)

Holotype. Male (SL 6.5 mm), Marion Plateau, Queensland, FRV Soe /a, sta. 0685 -30, 19°32.85'S, 152°34.8'E, 477- 470 m, 23 Nov 1985, NTM Cr 006854.

Paratypes. QUEENSLAND: 1 male (SL 4.3 mm) , 1 female ovig. (SL 3.7 mm), off Tully, ORV Franklin, sta. 47 -2, 16°51.8'S, 147°0.8'E, 500 m, 16 May 1986, QM W16512 . 1 female ovig. (SL 4.8 mm), off Tully, ORV Franklin, sta. 51-2, 18°03.9'S, 147°19.5'E, 689-704 m, 18 May 1986, QM W16505 . 2 males (SL 6.4-6.5 mm), 2 females (SL 5.1, 5.2 mm), same sta. data as holotype, NTM er 006854.

NEW SOUTH WALES: 1 female (SL 5.2 mm), E ofWooli, FRV Kapala , sta. K77-13-11, 29°55'S, 153°41'E, 502 m, 23 Aug 1977, AM P40391 . 2 males (SL 5.2, 5.8 mm), off Newcastle, 549 m, FRV Kapala, Apr 1971 , USNM 270113 . I male (SL 5.4 mm), transect between Sydney and Port Stevens , FRV Kapala , 366 m, Jul 1972, AM P19633 . 1 male (SL 7.3 mm), 6-8 mi (11.1-14.8 km) E of Sydney , 274 m, 10 Aug 1972, coil. D. Griffin and 1. Paxton, AM P40400 . 2 males (SL 5.8, 6.7 mm), 1 female (SL 4.2 mm), 1 female ovig. (SL 5.4 mm), 52 km ENE of Nowra , ORV Franklin, sta. SLOPE 57 , 34°43.55'S, 151°13.16'E, 450 - 345 m, 22 Oct 1988, coils. G.C.B. Poore et al., NMV 116200 .

Description. First 11 pairs of gills trichobranchiate. Shield ( Fig. 12a ) as broad as long, weakly calcified medially; dorsal surface with short rows of setae on each side of midline; rostrum broadly triangular, with short mid-dorsal ridge; anterior margins weakly concave; lateral projections broadly rounded; anterolateral margins slightly sloping; posterior margin broadly rounded. Anterodistal margin ofbranchiostegite rounded, unarmed.

Ocular peduncles more than half length of shield, with dorsal row of setae. Cornea slightly dilated. Ocular acicles subtriangular, terminating in strong multifid spine ( Fig. 12b,c ); separated basally by less than basal width of 1 acicle.

Antennular peduncle long, slender, exceeding distal margin of corneae by length of ultimate segment. Ultimate segment 1.5 times or more as long as penultimate segment, with scattered setae. Basal segment with strong ventromesial spine on lateral face, distal subrectangular lobe with 2 small spines and strong spine proximally. Ventral flagellum with about 9 to 13 articles

Antennal peduncle ( Fig. 12d ) slightly exceeding distal margin of cornea. Fifth segment unarmed, with row of setae on distolateral angle. Fourth segment usually unarmed (occasionally with small spine on dorsolateral distal angle). Third segment with strong ventromesial distal spine. Second segment with dorsolateral distal angle produced, terminating in strong, simple to bifid spine (often with small additional spine dorsally); mesial margin with spine on dorsodistal angle. First segment with small spine on lateral face; ventromesial angle produced, with 5 small spines laterally. Acicles slightly curved laterally (dorsal view), at most exceeding slightly distal margin of cornea, terminating in strong spine; mesial margin armed with row of 9 to 12 spines, setose. Flagellum long, reaching to tip of fingers of extended right cheliped, with scattered short setae less than 1 article in length.

Mandible with 3-segmented palp. Maxillule (Fig. 13a,b) with external lobe of endopod moderately developed, internal lobe with long seta distally. Maxilla with endopod exceeding distal margin of scaphognathite. First maxilliped with endopod exceeding exopod in distal extension. Second maxilliped without distinguishing characters. Third maxilliped (Fig. 13c) with crista dentata of 14 corneous-tipped teeth; basis and coxa each with small spine mesially. Sternite of 3rd maxillipeds with spine on each side of midline. Epistome unarmed. Labral spine present.

Chelipeds markedly dissimilar. Right cheliped ( Figs 12f , 14a ) covered with moderately dense setae (setae not shown in Fig. 12f ). Fingers weakly curved ventromesially, tips crossed when closed and terminating in small corneous claws; cutting edges each with irregularly-sized calcareous teeth; dorsal surfaces with numerous sharp and blunt spines. Dactyl subequal in length to palm, set at oblique angle to longitudinal axis of palm; mesial margin well defined by row of spines; ventromesial face weakly concave. Palm about as long as broad, mesial and lateral faces rounded, with small spines; dorsal and ventral faces densely covered with sharp and blunt spines (less dense on ventral face and often on dorsal face in small specimens SL <5.0 mm). Carpus with all faces densely covered with sharp and blunt spines (less dense on ventral face). Merus with row of small tubercles on dorsal margin; dorsolateral face with scattered small tubercles; ventral face with numerous well-spaced small tubercles. Ischium ventral face armed with small spines. Coxa with setose ventromesial margin.

Left cheliped ( Fig. 12e ) evenly calcified, covered with dense (ventral surfaces) to moderately dense setae (dorsal surfaces). Fingers with tips crossed when closed, terminating in small corneous claws; dorsal surfaces with small spines on proximal half; dorsal and ventral surfaces with scattered tufts of setae. Dactyl subequal in length to palm; cutting edge with row of small, fused corneous spinules. Fixed finger with cutting edge with evenly-sized, small calcareous teeth and overlapping row of fused corneous spinules. Palm with numerous spines on dorsal surface. Carpus with small dorsodistal spine, and small spine at laterodistal angle; dorsolateral face with scattered small, blunt spines; dorsal margin with row of 3 or 4 small spines. Merus and ischium unarmed. Coxa with setose ventromesial margin.

Ambulatory legs (Fig. l3d-±) similar from right to left, long, reaching or exceeding tips of fingers of extended right cheliped. Dactyl long, about twice as long as propodus, terminating in sharp corneous claw; ventral margin armed with row of 7 to 11 small corneous spines; with dorsodistal and dorsomesial row of long setae. Propodi with short setae on dorsal margin. Carpus with small dorsodistal spine, and row of short setae dorsally. Merus with row of short setae dorsally and occasionally with row of small spines in specimens SL <5.0 mm; merus of 2nd pereopod with row of blunt to sharp tubercles on ventral margin distally, merus of 3rd pereopod unarmed. Ischium and coxa unarmed. Anterior lobe of sternite of 3rd pereopods ( Fig. 12g ) unarmed, setose.

Fourth pereopod (Fig. 13g) semichelate. Dactyl subtriangular, terminating in sharp corneous claw, and with ventrolateral row of small corneous spinules. Propodus longer than broad, rasp formed of I row of rounded or ovate scales. Carpus and merus with dense setae on dorsal margins.

Fifth pereopod (Fig. 13h) semichelate. Propodal rasp extending to mid-length of segment.

Uropods and telson ( Fig. 12 h-j) asymmetrical. Telson with anterior and posterior lobes separated by weak transverse suture, dorsal surface with scattered setae; posterior lobes separated by V-shaped cleft, terminal margins of lobes armed with strong corneous spines.

Males with paired Ist and 2nd gonopods well developed. First gonopods (Fig. 13i) each with concave distal lobe. Second gonopods (Fig. 13j) each with distal segment nearly flat, setose on lateral and mesial margins and on distal portion of anterior face. Female with vestigial 2nd right pleopod.

Habitat and symbiotic associations. Gastropod shells.

Distribution. So far known only from Australia. Depth: 274 to 704 m.

Etymology. The specific name is for the FRV Soela, in recognition of the collecting efforts conducted on this ship.

Affinities. This species is most similar to Sympagurus affinis ( Henderson, 1888) . The two can be separated by the armature of the dorsal surface of the right and left chelae. In S. soela both chelae have numerous spines on the dorsal surface ( Fig. 12e,f , 14a ), whereas in S. affinis the chelae are unarmed dorsally.

Remarks. In a study ofparapagurids from French Polynesia, Lemaitre (1994: 381) mentioned that he had examined specimens of S. affinis from Australia. Further study of those specimens has shown that they actually represent the new species S. soela . Although S. affinis is broadly distributed in the central and western Pacific ( Indonesia, Philippines, Hawaiian Islands, and French Polynesia), so far it has not been found in Australian waters.

Figures

Fig. 12. Sympagurus soela n.sp. a, shield and cephalic appendages; b,c, ocular acicles, dorsal; d, right antennal peduncle, lateral; e, left cheliped; f, right chela, mesial (setae omitted); g, stemite of 3rd pereopods; h,i, exopod of uropods, dorsal: h, left; i, right; telson. Scales = 3 mm (a,e,t), and 1 mm (b-d,g-j). (Queensland, NTM er 006854: a,b, d-j, holotype male [SL 6.5 mm]; c, paratype male [SL 6.4 mm]).

Fig. 14. Right chelipeds: a, Sympagurus soela n.sp. (2.5x). b,c, S. villosus n.sp.: b, carpus and chela, dorsal (2.8x); c, chela, mesial (2.5x). d,e, Paragiopagurus diogenes (Whitelegge, 1900): d, dorsal (2.7x); e, mesial (l.8 x).