Catapaguroides crassimanus, 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 : 153-158

Catapaguroides crassimanus , new species

( Figs. 6–8 )

Material examined. –– Holotype: female (sl 1.1 mm), PANGLAO 2004, stn T14 , Maribohoc Bay, Bohol Island , 09°41.5'N, 123°49.3'E, 101–110 m, mud with shells, 17 Jul.2004, NMCR 39063.

Comparative material. –– Catapaguroides fragilis ( Melin, 1939) : 1 female (sl 1.1 mm), TRV Toyoshio-maru , 1996-6 cruise, stn 7, SE of Tanegashima Island, Ohsumi Islands, Japan, 30°15.00'N, 130°45.00'E, 75 m, 2 Jun.1996, dredge, coll. T. Komai, CBM-ZC 9018 .

Description. –– Ten pairs of biserial phyllobranchiate gills; 2 arthrobranchs on third maxilliped each reduced to minute bud; other arthrobranchs distinctly lamellate; no pleurobranchs on wall of seventh thoracic somite.

Shield ( Fig. 6A ) as long as wide; anterior margins between rostral lobe and lateral projections concave; anterolateral margins sloping, posterior margin rounded; dorsal surface almost glabrous, with tufts of short setae laterally. Rostrum rounded. Lateral projections triangular, produced to level of rostrum, each with submarginal spinule.

Ocular peduncle ( Fig. 6A ) about 0.9 length of shield, slender, not markedly widened basally; dorsal surface with tuft of moderately long setae at base of cornea, followed by tufts of or individual setae; cornea normally developed, rounded, not dilated, longer than wide, corneal width approximately 0.3 of peduncular length. Ocular acicle small, triangular, without submarginal or subterminal spinule, separated to each other basally by basal width of more than 1 acicle. Interocular lobe with convex anterior surface.

Antennular peduncle ( Fig. 6A ), when fully extended, overreaching distal corneal margin by full length of ultimate segment. Basal segment with spinule proximolaterally. Ultimate segment 0.7 length of shield, slightly broadened distally in lateral view, with 2 long plumose setae at dorsolateraldistalportion.Dorsalflagellumwithdistalportion distinctly longer than proximal aesthetasc-bearing portion.

Antennal peduncle ( Fig. 6A ) 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 spine nearly reaching midlength of fourth segment; dorsomesial distal angle with minute spine. First segment unarmed. Antennal acicle slender, slightly sinuous, slightly falling short of distal corneal margin, terminating in slender spine and with row of short to long setae over entire length. Antennal flagellum long, exceeding 4.0 times of shield length; articles each with 1 short or long seta at each lateral and mesial angle.

Third maxilliped relatively stout; crista dentata on ischium consisting of 2 teeth ( Fig. 6B ). Carpus without dorsodistal spine.

Chelipeds ( Figs. 7 , 8A–D ) distinctly unequal in length and dissimilar. Right cheliped ( Fig. 7 ) large, but not particularly elongate; propodal-carpal articulation rotated clockwise about 30° from perpendicular. Chela about 1.7 times longer than wide, widest at base of dactylus. Dactylus articulating obliquely with palm, about 0.7 length of palm, somewhat curved ventrally; dorsal surface convex, dorsomesial margin not delimited, unarmed; cutting edge with 3 prominent, triangular calcareous teeth, terminating in tiny corneous claw; tufts of short to moderately long setae arranged in irregular longitudinal rows on surfaces. Palm 1.1 times longer than carpus; dorsal surface convex, bearing several tiny tubercles chiefly on mesial half and 1 prominent proximomedian tubercle; and scattered short setae; dorsolateral and dorsomesial margins not delimited; lateral and mesial faces with few tufts of short to moderately long setae; ventral surface slightly convex, almost glabrous. Fixed finger with 2 prominent calcareous teeth on cutting edge, terminating in minute corneous claw. Carpus about 1.4 length of merus, slightly broadened distally, about 1.6 times longer than distal width; dorsal surface devoid of conspicuous spines, but mesially with few tiny tubercles and laterally with longitudinal row of 3 tiny tubercles, dorsodistal margin also with tiny tubercle laterally; dorsomesial margin not delimited; mesial surface with short to long stiff setae dorsally, ventromesial margin with tiny distal spine; lateral surface with few short setae dorsally, ventrodistal angle slightly produced, but unarmed; ventral surface convex, with few short setae. Merus with row of sparse short to long setae on dorsal surface; dorsodistal margin with 1 small spine mesially; lateral surface glabrous, ventrolateral margin slightly concave, with 3 moderately small spines in distal half; mesial surface also glabrous, ventromesial margin with 4 spines in distal half; ventral surface strongly convex, with few moderately short setae. Ischium unarmed, with short setae on dorsal margin.

Left cheliped ( Fig. 8A–D ) relatively slender, reaching base of dactylus of right cheliped; propodal-carpal articulation rotated counterclockwise 20° from perpendicular. Chela 2.5 times longer than wide, not arched. Dactylus and fixed finger slightly curved ventrally, without hiatus; dactylus about 1.5 length of palm, unarmed, with scattered tufts of short to long setae; dorsomesial margin not delimited; cutting edge with row of minute corneous teeth, terminating in small corneous claw. Palm about half length of carpus; dorsal surface slightly convex, with 2 spines mesially; surfaces with tufts of or individual short to long setae arranged in irregular longitudinal rows. Fixed finger with row of minute corneous teeth on distal half of cutting edge, terminating in small corneous claw. Carpus longer than merus; slightly widened distally, about 2.7 times longer than distal width; dorsal surface laterally with 1 small spine (located slightly distal to midlength) and mesially with 3 spines, 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 scattered short setae; ventrolateral distal angle with 1 small spine; ventral surface slightly convex, with some short to long setae. Merus with row of short setae on dorsal margin; dorsodistal margin unarmed; ventrolateral margin slightly concave in distal half, with 2 spines subdistally (distal spine minute, proximal spine strong); ventromesial margin also with 2 small spine in distal half, similarly unequal as those on ventrolateral margin; ventral surface strongly convex, with several scattered long setae. Ischium spineless.

Ambulatory legs ( Fig. 8E, G ) long and slender (right second pereopod missing). Dactyli ( Fig. 8F, H ) 1.5–1.6 times longer than propodi, 13.4 times longer than wide, straight in dorsal view, slightly curved ventrally in lateral view, terminating in long, slender corneous claws; dorsal margins each with row of stiff setae increasing in length distally, distal 5 or 6 setae thickened, bristle-like; mesial faces each with row of stiff setae on midline; ventral margin unarmed. Propodi each with pair of (second) or single mesial (third) corneous spinules on ventrodistal margin (spinules on second longer than those of third); dorsal and ventral margins with sparse short to long stiff setae. Carpi each unarmed at dorsodistal angle, few short to long setae on dorsal margin. Meri each armed with 1 distal and 1 subdistal spines on ventrolateral margin (second) or unarmed (third); dorsal and ventral margins each with row of short to long setae. Ischium with few long setae on dorsal and ventral margins. Second pereopods with shallow notch on ventral margin at articulation between merus and ischium. Female with unpaired left gonopore.

Fourth pereopod ( Fig. 6C ) semichelate; dactylus with several minute corneous teeth on ventral margin; propodal rasp consisting of 7 corneous scales arranged in single row. Fifth pereopods semichelate.

Anterior lobe of sixth thoracic sternite ( Fig. 6D ) subsemicircular, slightly skewed to left, with long setae on anterior margin.

Telson ( Fig. 6E ) longer than wide, narrowed posteriorly in posterior half; no lateral indentations; posterior lobes strongly asymmetrical, separated by deep median cleft; left terminal margin with 2 strong spines and laterally directed, spinose outer angle, right terminal margin strongly oblique, with 1 small spine and spinose outer angle.

Male unknown.

Colouration. –– Not known.

Distribution. –– Known only from the type locality, 101– 110 m.

Remarks. –– Catapaguroides crassimanus , new species, appears close to C. fragilis ( Melin, 1939) and C. setosus ( Edmondson, 1951) in the following characters: cornea normally developed; antennal peduncle not overreaching distal corneal margin; right chela with subrectangular palm in dorsal view; and palm and carpus of left cheliped armed with spines on dorsal surface. The structure and armature of the right cheliped is considerably different among the three species. In C. crassimanus , the dorsomesial margin of the dactylus is not delimited; the palm is slightly widened distally, 1.1 times longer than wide, and bears scattered tiny tubercles on the mesial half of the dorsal surface and one relatively prominent tubercle proximally on the dorsal midline; the dorsolateral margin of the palm is not delimited; and the carpus bears tiny tubercles on the dorsal surface, but without mesial spines arranged in a longitudinal row. In C. fragilis , the dorsomesial margin of the dactylus is not delimited; the palm is not particularly widened distally, 1.4 times longer than wide, and bears a mesial row of small spines and one prominent proximal spine on the dorsal surface; the dorsolateral margin of the palm is not delimited; and the carpus bears a row of spines on the dorsolateral margin (de Saint Laurent, 1968; this study). In C. setosus , the dorsomesial margin of the dactylus is provided with a prominent, thin ridge; the palm is distinctly widened distally and armed with a dorsomesial row of four small spines; the dorsolateral margin of the palm is delimited by a slightly elevated ridge; the carpus is devoid of conspicuous spines (McLaughlin & Pittman, 2002). Furthermore, the antennular peduncle overreaches the distal corneal margin by the full length of the ultimate segment in the new species, but it overreaches the latter only by 0.3–0.5 length of the ultimate segment in C. fragilis and C. setosus (McLaughlin & Pittman, 2002; this study). The armature of the telson is also different among the three species. The terminal margins of the posterior lobes bear prominent spines (those on the left lobe are particularly strong) in C. crassimanus , but they are unarmed in C. setosus . de Saint Laurent (1968) described the armature of the terminal margins of the telson of C. fragilis as “trois epines fines et courtes sur le bord interne”. In the specimen of C. fragilis examined in this study, the left terminal margin is unarmed, while the right terminal margin bears one tiny spine.

Etymology. –– From the combination of the Latin, “ crassus ” [= thick] and “ manus ” [= hand], in reference to the relatively

thick female right cheliped in this new species. Used as a noun in apposition.

Figures

Fig. 6. Catapaguroides crassimanus, new species, holotype, female (sl 1.1 mm), PANGLAO 2004, stn T14, NMCR 39063. A, shield and cephalic appendages, dorsal view; B, ischium-basis of right third maxilliped, ventral view; C, left fourth pereopod, lateral view; D, sixth thoracic sternite, ventral view: E, telson, dorsal view. Scale bars = 0.5 mm.

Fig. 7. Catapaguroides crassimanus, new species, holotype, female (sl 1.1 mm), PANGLAO 2004, stn T14, NMCR 39063.A, right cheliped, mesial view; B, same, lateral view (setae omitted); C, same, chela, dorsal view; D, same, carpus, dorsal view. Scale bar = 0.5 mm.

Fig. 8. Catapaguroides crassimanus, new species, holotype, female (sl 1.1 mm), PANGLAO 2004, stn T14, NMCR 39063.A, left cheliped, mesial view; B, same, lateral view (setae omitted); C, same, chela, dorsal view; D, same, carpus, dorsal view; E, left second pereopod, lateral view; F, same, dactylus, mesial view; G, left third pereopod, lateral view; H, same, dactylus, mesial view. Scale bar = 0.5 mm.