Catapaguroides levigatus, Komai & Rahayu, 2013

Komai, Tomoyuki & Rahayu, Dwi Listyo, 2013, The Hermit Crab Genus Catapaguroides A. Milne-Edwards & Bouvier, 1892 (Crustacea: Decapoda: Anomura: Paguridae) From The Bohol Sea, Philippines, With Descriptions Of Eight New Species, Raffles Bulletin of Zoology 61 (1), pp. 143-188 : 171-175

Catapaguroides levigatus , new species

( Figs. 18–20 )

Material examined. –– Holotype: female (sl 1.4 mm), PANGLAO 2004, stn B15, Sunglolan , Panglao Island, 09°38.8'N, 123°49.2'E, 2–4 m, reef wall with dead coral, 16 Jun.2004, NMCR 39065.

Paratypes: 2 males (sl 1.2, 1.4 mm), 2 females (sl 1.0, 1.2 mm), 1 ovigerous female (sl 1.2 mm), PANGLAO 2004, stn S29, Pamilacan Island , 09°29.4'N, 123°56.0'E, 32 m, wall and floor of small cavern, 25 Jun.2004, ZRC 2012.1095 ; 1 male (sl 1.1 mm), 1 ovigerous female (sl 1.3 mm), same data, CBM-ZC 11356 .

Description. –– Ten pairs of biserial phyllobranchiate gills; 2 arthrobranchs on third maxilliped small, weakly lamellate; other arthrobranchs distinctly lamellate; no pleurobranchs on wall of seventh thoracic somite.

Shield ( Fig. 18A ) approximately as long as wide; anterior margins between rostral lobe and lateral projections concave; anterolateral margins terraced; posterior margin rounded, medially emarginate; dorsal surface almost glabrous, with few tufts of short setae laterally. Rostrum triangular, pointed distally. Lateral projections also triangular, slightly falling short of rostrum, with submarginal spinule.

Ocular peduncle ( Fig. 18A ) about 0.8 length of shield, slender, slightly widened basally; dorsal surface with 2 or 3 tufts of short setae in distal half; additional tuft of setae on each lateral and mesial surface near corneal base; cornea normally developed, rounded, not dilated, longer than wide, corneal width about 0.2 of peduncular length. Ocular acicle small, triangular, with submarginal terminal spinule, separated to each other basally by basal width of 2 acicles. Interocular lobe with straight or slightly convex anterior surface.

Antennular peduncle ( Fig. 18A ), when fully extended, overreaching distal corneal margin by half length of ultimate segment. Basal segment with spinule proximolaterally. Ultimate segment 0.6 length of shield, slightly broadened distally in lateral view, with 2 long plumose setae at dorsolateral distal portion. Dorsal flagellum with distal portion distinctly longer than proximal aesthetasc-bearing portion.

Antennal peduncle ( Fig. 18A ) slightly falling short of distal corneal margin. Fifth and fourth segments with few short setae. Third segment with 1 prominent spine at ventromesial distal margin. Second segment with dorsolateral distal angle produced in simple or bifid spine nearly reaching midlength of fourth segment; dorsomesial distal angle with small spine. First segment unarmed. Antennal acicle slender, slightly sinuous, slightly falling short of distal corneal margin, terminating in slender spine, with row of short to long stiff setae in distal half. Antennal flagellum exceeding 4.0 times of shield length; articles each with several short to long setae on distal margin (long setae present every 2 or 3 articles).

Third maxilliped moderately stout, with crista dentata on ischium consisting of 3 or 4 strong teeth ( Fig. 18B ). Carpus without dorsodistal spine.

Chelipeds ( Fig. 19 ) distinctly unequal and dissimilar. Right cheliped ( Fig. 19A–E ) large, not particularly elongate; propodal-carpal articulation rotated clockwise about 20° from perpendicular. Chela subovate in dorsal view, about 1.8 times (males) or 2.4 times (females) longer than wide, widest at base of dactylus. Dactylus articulating slightly obliquely with palm, about 0.7–0.9 length of palm, slightly curved ventrally; dorsal surface convex, dorsomesial margin not delimited, armed with 1 small spine proximally; cutting edge with 3 prominent, triangular calcareous teeth, terminating in tiny corneous claw; tufts of short to moderately long setae on surfaces. Palm about 0.8 length of carpus; dorsal surface convex, entirely unarmed, with tufts of short to moderately long setae arranged in some irregular longitudinal rows; lateral and mesial faces also with few short to moderately long setae; ventral surface slightly convex, with some long setae. Fixed finger with 2 or 3 prominent calcareous teeth on cutting edge, terminating in minute corneous claw. Carpus 1.2–1.3 length of merus, noticeably widened distally, about 1.1 times (male) or 1.6 times (female) longer than distal width; dorsal surface with 1–3 small spines on dorsolateral margin and with 1 spine on dorsomesial margin proximal to midlength; dorsodistal margin with 1 spine at each lateral and mesial angle; lateral surface almost glabrous, ventrolateral distal angle with 1 small spine; mesial face with some long setae dorsally; ventral surface gently convex. Merus with few tufts of setae on distal half of dorsal surface; dorsodistal margin with 1 small spine mesially; lateral surface glabrous, ventrolateral margin nearly straight, with 2 small subdistal spines; mesial surface also almost glabrous, ventromesial margin with 3 small spines distally; ventral surface slightly convex, with some long setae. Ischium unarmed, with short setae on mesial and ventral surfaces.

Left cheliped ( Fig. 19F–I ) slender, reaching beyond base of dactylus of right cheliped; propodal-carpal articulation without rotation. Chela slightly arched ventrally, 4.0–4.2 times longer than wide; no hiatus between fingers. Dactylus about 1.1 length of palm, unarmed, with tufts of short to long setae; dorsomesial margin not delimited; cutting edge with row of widely spaced minute corneous teeth, terminating in small corneous claw. Palm about 0.5 length of carpus; dorsal surface slightly convex, unarmed; surfaces with tufts of short to long setae arranged in irregular longitudinal rows. Fixed finger with or without corneous teeth on cutting edge, terminating in small corneous claw. Carpus slightly widened distally, 3.2–3.3 times longer than distal width; dorsal surface laterally unarmed, mesially with 1 small spine proximal to midlength, and with tufts of long setae laterally and mesially; dorsodistal margin armed with 1 spine at each lateral and mesial angle; lateral and mesial faces with few long setae, ventrolateral distal angle unarmed; ventral surface slightly convex, with some short to long setae. Merus with few long setae on dorsal margin; dorsodistal margin unarmed; ventrolateral margin, with 2 small spines subdistally; ventromesial margin with 1 small distal spine; ventral surface slightly convex, with several long setae. Ischium unarmed.

Ambulatory legs ( Fig. 20A, C ) long and slender. Dactyli ( Fig. 20B, D ) 1.3–1.5 times longer than propodi, 12.9–14.0 times longer than wide, straight in dorsal view, slightly curved ventrally in lateral view, terminating in slender corneous claws; dorsal margins each with row of sparse stiff setae increasing in length distally, distal 3 or 4 setae thickened, bristle-like; mesial faces each with row of stiff setae on midline; ventral margins with 5–7 slender spines noticeably increasing in length distally. Propodi each with pair of corneous spines on ventrodistal margin in both male and female (second) or single mesial spine (third); dorsal and ventral margins with sparse, short and long stiff setae. Carpus with minute dorsodistal spine and with short and long setae (more numerous on second) on dorsal margins. Merus unarmed or armed with 1 minute subdistal spine on ventrolateral margin; dorsal and ventral margins each with sparse stiff setae. Ischium glabrous (second) or with long setae on ventral margins (third). Second pereopods with deep notch on ventral margin at articulation between merus and ischium. Female with unpaired left gonopore.

Fourth pereopod ( Fig. 18C ) semichelate; dactylus with several minute corneous teeth on ventral margin; propodal rasp consisting of 7 or 8 corneous scales arranged in single row. Fifth pereopods semichelate.

Anterior lobe of sixth thoracic sternite ( Fig. 18E ) subsemicircular, slightly skewed to left, with short setae on anterior margin.

Male with long sexual tube extending from coxa of right fifth pereopod ( Fig. 18D ), directed from right to left across ventral body surface and far overreaching lateral margin of left coxa, then slightly curved anteriorly, tapering to rounded tip; left coxa with short sexual tube directed anteromesially, partially obscured by tufts of dense setae arising from eighth thoracic sternite.

Telson ( Fig. 18F, G ) slightly longer than wide, narrowed posteriorly in posterior half; no lateral indentations; posterior lobes strongly asymmetrical, separated by narrow median cleft; terminal margins oblique, left with 3 or 4 tiny spinules, right with 3 minute spinules, left angle spinose, right angle not spinose.

Eggs shrunk, about 0.4 × 0.5 mm.

Colouration. –– Not known.

Distribution. –– Known only from the type locality, 2– 32 m.

Remarks. –– Catapaguroides levigatus , new species, resembles C. hirsutus , new species, in sharing the following characters: cornea normally developed, rounded; antennal peduncle not reaching distal corneal margin; palm of right cheliped non-operculiform, without spines on dorsal surface; left cheliped with unarmed palm and carpus bearing one or more dorsal spines. However, C. levigatus is readily distinguished from C. hirsutus by the distinctly shorter antennular peduncle (overreaching the distal corneal margin by the half length of the ultimate segment versus by the full length of that segment), the non-elongate right cheliped and the dactyli of the ambulatory legs armed with five to seven slender corneous spinules on ventral margins. In C. hirsutus , the ambulatory dactyli are unarmed or armed only with one submedian corneous spine on ventral margins.

Etymology. –– From the Latin “ levigatus ” [= smooth], alluding to the unarmed palm of the right cheliped.

Figures

Fig. 18. Catapaguroides levigatus, new species. A–D, F, holotype, female (sl 1.4 mm), PANGLAO 2004, stn B15, NMCR 39065; E, G, paratype, male (sl 1.2 mm), PANGLAO 2004, stn S29, ZRC 2012.1095. A, shield and cephalic appendages, dorsal view; B, ischiumbasis of left third maxilliped, ventral view; C, left fourth pereopod, lateral view; D, sixth thoracic sternite, ventral view; E, coxae of fifth pereopods and eighth thoracic sternite, ventral view; F, G, telson, dorsal view. Scale bars = 0.5 mm (A); 0.25 mm (B–G).

Fig. 19. Catapaguroides levigatus, new species. A–C, F–I, holotype, female (sl 1.4 mm), PANGLAO 2004, stn B15, NMCR 39065; D, E, paratype, male (sl 1.2 mm), PANGLAO 2004, stn S29, ZRC 2012.1095. A, right cheliped, mesial view; B, same, lateral view (setae omitted); C, same, chela and carpus, dorsal view; D, right chela, dorsal view; E, carpus of right cheliped, dorsal view; F, left cheliped, mesial view (tip of dactylus broken); G, same, lateral view (setae omitted); H, same, chela, dorsal view; I, same, carpus, dorsal view. Scale bar = 0.5 mm.

Fig. 20. Catapaguroides levigatus, new species, holotype, female (sl 1.4 mm), PANGLAO 2004, stn B15, NMCR 39065. A, right second pereopod, lateral view; B, same, dactylus, mesial view; C, left third pereopod, lateral view; D, same, dactylus, mesial view. Scale bars = 0.5 mm.