Catapaguroides karubar McLaughlin, 1997

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 : 167-171

Catapaguroides karubar McLaughlin, 1997

( Figs. 15–17 )

Catapaguroides karubar McLaughlin, 1997: 458 , fig. 7a–h; McLaughlin et al., 2010: 28 (list)

Material examined. –– One male (sl 1.0 mm), PANGLAO 2004, stn T39 , W of Pamilacan Island , 09°30.1'N, 123°50.4'E, 100–138 m, muddy sand, 6 Jul.2004, ZRC 2012.1094 .

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

Shield ( Fig. 15A ) approximately as long as wide; anterior margins between rostral lobe and lateral projections concave; anterolateral margins sloping, posterior margin roundly truncate; dorsal surface with tufts of short setae laterally. Rostrum roundly triangular. Lateral projections triangular, produced to level of rostrum, each with submarginal spinule.

Ocular peduncle ( Fig. 15A ) subequal in length to shield, slender, not widened distally or proximally; dorsal surface mesially with 3 tufts of moderately long setae in distal 0.7; cornea normally developed, rounded, not dilated, slightly longer than wide, corneal width about 0.2 of peduncular length. Ocular acicles small, triangular, sharply pointed, each with minute submarginal spinule concealed by terminal point in dorsal view, separated to each other basally by basal width of 2 acicles. Interocular lobe with slightly convex anterior surface.

Antennular peduncle ( Fig. 15A ), when fully extended, overreaching distal corneal margin by nearly full length of ultimate segment. Basal segment elongate, with small spine proximolaterally. Ultimate segment 0.7 length of shield, slightly widened distally in lateral view, with 2 long plumose setae at dorsolateral distal portion. Dorsal flagellum (left broken distally) slightly longer than ultimate segment, distal portion about twice length of proximal aesthetasc-bearing portion.

Antennal peduncle ( Fig. 15A ) slightly falling short of distal corneal margin. Fifth and fourth segments with few short setae. Third segment with 1 prominent spine at ventromesial distal angle. Second segment with dorsolateral distal angle strongly produced in simple or bifid spine slightly overreaching midlength of fourth segment; dorsomesial distal angle with small spine. First segment unarmed. Antennal acicle slender, faintly sinuous, slightly falling short of distal corneal margin, terminating in slender spine, with row of short to long stiff setae along entire length. Antennal flagellum exceeding 4.0 times of shield length; articles each with several short to long setae on distal margin (long setae present every 4 or 5 articles).

Third maxilliped moderately stout; crista dentata on ischium consisting of 2 sharp teeth ( Fig. 15B ). Carpus without dorsodistal spine.

Chelipeds ( Fig. 16 ) appreciably unequal and dissimilar. Male right cheliped ( Fig. 16A–D ) large, not particularly elongate; propodal-carpal articulation rotated clockwise about 30° from perpendicular. Chela operculiform, about 1.7 times longer than wide, widest at base of dactylus. Dactylus broad, articulating obliquely with palm, about 0.8 length of palm, slightly curved ventrally; dorsal surface slightly elevated in midline, unarmed, with tufts of short setae along midline and mesial margin; mesial margin distinctly carinate, but not lamellar; ventral surface slightly concave mesially, with few short setae; cutting edge with 2 roundly triangular calcareous teeth, terminating in minute corneous claw. Palm about 1.2 length of carpus, widened distally; dorsal surface convex, with 2 widely spaced mesial spines on proximal two-thirds and 2 proximal submedian tubercles, scattered short setae present submarginally; dorsolateral margin distinctly carinate, slightly upturned, but not lamellar; dorsomesial margin not delimited; ventral surface slightly convex, almost glabrous. Fixed finger very broad, with 2 blunt calcareous teeth on cutting edge, terminating in small calcareous claw. Carpus 1.1 length of merus, widened distally, about 1.4 times longer than distal width; dorsal surface with 2 small spines on dorsal midline, including distal marginal spine; dorsomesial distal angle with 1 spine; lateral surface almost glabrous, ventrolateral distal angle unarmed; mesial face with sparse short to long setae; ventral surface convex. Merus with few stiff short setae on dorsal surface; dorsodistal margin with 1 strong spine mesially; lateral surface glabrous, ventrolateral margin with 2 tiny subdistal tubercles; mesial surface also almost glabrous, ventromesial margin raised, with 2 strong spines distally and numerous long setae; ventral surface convex, with few long setae. Ischium unarmed.

Left cheliped ( Fig. 16E–G ) relatively stout, reaching midlength of right chela; propodal-carpal articulation rotated counter-clockwise 20° from perpendicular. Chela not arched; no hiatus between fingers. Dactylus about 1.1 length of palm, unarmed, with sparse tufts of short setae; dorsomesial margin not delimited; cutting edge with row of minute corneous teeth in distal half. Palm about 0.6 length of carpus; dorsal surface slightly convex, unarmed; surfaces with scattered short setae. Fixed finger bordered with thin corneous cutting edge, terminating in small calcareous claw. Carpus slightly widened distally; dorsal surface mesially with 1 spine at midlength; dorsodistal margin armed with 2 spines including one at dorsomesial distal angle; ventral surface gently convex; surfaces with sparse short to long setae. Merus with few short setae on dorsal margin; dorsodistal margin unarmed; ventrolateral margin with 2 closely spaced, small spines subdistally; ventromesial margin with 1 small distal spine; ventral surface slightly convex, with several long setae. Ischium unarmed.

Ambulatory legs ( Fig. 17A, C ) long and slender. Dactyli ( Fig. 17B, D ) 1.5–1.7 times longer than propodi, 10.6–11.0 times longer than wide, straight in dorsal view, slightly curved ventrally in lateral view, terminating in elongate, slender corneous claws; dorsal margins each with row of thick, bristle-like setae increasing in length distally; mesial faces each with 4–6 slender corneous spines and few short setae adjacent to ventral margin. Propodi each with single long corneous spine flanked by 2 or 3 shorter spines (second) or with only small corneous spine (third) on ventrodistal margin; dorsal and ventral margins each with 1 or 2 short setae. Carpi each with small dorsodistal spine and few short dorsal setae. Meri each with 1 small ventrolateral distal spine (second) or unarmed (third); dorsal margins each with few short setae. Ischia unarmed. Second pereopods with deep notch on ventral margin at articulation between merus and ischium.

Fourth pereopod ( Fig. 15C ) semichelate; dactylus with several minute corneous teeth on ventral margin; propodal rasp consisting of 6 corneous scales arranged in single row. Fifth pereopods semichelate.

Anterior lobe of sixth thoracic sternite ( Fig. 15D ) subsemicircular, slightly skewed to left, with sparse short setae on anterior margin. Lobe of eighth thoracic sternite bearing numerous short setae ( Fig. 15E ).

Male with short and stout sexual tube extending from coxa of right fifth pereopod ( Fig. 15E ), directed slightly posterior from right to left across ventral body surface, not reaching lateral margin of left coxa. Left coxa with papilla-like sexual tube directed anteromesially.

Telson ( Fig. 15F ) narrowed posteriorly in posterior half; no lateral indentations; posterior lobes slightly asymmetrical, separated by shallow median cleft; terminal margins strongly oblique, left with 2 spinules, right with 3 spinules, outer angles acutely pointed.

Colouration. –– In preservative: Colour substantially faded away, but iridescence on chelipeds and red blotches on chelipeds and ambulatory legs still preserved. Right cheliped with carpus bearing red blotches on dorsal and mesial surfaces located medially; merus with 2 red blotches on mesial face. Left cheliped with similar colour pattern to right cheliped, though mesial face of merus with only 1 blotch. Ambulatory legs with propodi each bearing 1 large red spot on lateral surface located distal to midlength; carpi each with 1 red spot on lateral surface distal to midlength; meri each with 2 large red spots.

Distribution. –– Previously known from Kai Islands, Indonesia, at depths of 205– 212 m. The present specimen

represents the first record of this species from the Philippines, and slightly extends the bathymetric range to 83 m.

Remarks. –– Catapaguroides karubar was originally described on the basis of a single female holotype from Kai Islands, Indonesia ( McLaughlin, 1997). There have been no subsequent records of this species since the original description. The present male specimen agrees with C. karubar in the following diagnostic characters: ocular peduncle not widened distally or proximally with cornea normally developed, rounded; antennular peduncle overreaching distal corneal margin by slightly less than length of ultimate segment; antennal peduncle falling short of distal corneal margin; right chela operculiform, with distinct carinae on mesial margin of dactylus and lateral margin of palm; dorsal surface of right palm armed with a few mesial and proximal spines or tubercles; carpus of right cheliped with 2 spines on dorsal midline; and palm of left cheliped spineless. Nevertheless, it differs from the holotype female in the following points: the right palm is more lengthened in the present specimen than in the holotype, with the lateral margin not lamellar (lamellar in the holotype); the dorsal surface of the right palm is armed with two mesial spines and two proximal tubercles in the present specimen, rather than having one mesial spine at the midlength and two sharp proximal spines in the holotype; the crista dentata of the third maxilliped consists of only two sharp teeth in the present specimen, rather than five or six teeth in the holotype; and the posterior lobes of the telson are less produced and less acuminate in the present specimen than in the holotype. Most of these differences could be attributed to intraspecific variation. In particular, the difference in the shape of the right chela might be sex-related, as seen in the close relative C. cristimanus . The difference in the shape and armature of the telson is substantial, but it is difficult to assess this difference is of specific significance. Consequently, the present male specimen is provisionally referred to C. karubar .

As McLaughlin (1997) noted, C. karubar appears closest to C. cristimanus in the operculiform right chela with sharply carinate mesial margin of the dactylus and lateral margin of the palm. Differentiating characters of the two species are reassessed on the basis of the original descriptions and examination of the present specimens. Catapaguroides karubar can be distinguished from C. cristimanus primarily by the different armature of chelipeds: the right palm is armed with one or two dorsomesial and two proximal spines or tubercles in C. karubar , whereas it is armed only with three or more dorsomesial spines in C. cristimanus ; the carpus of the right cheliped bears only two spines on the dorsal midline in C. karubar , rather than a distinct row of five or six spines in C. cristimanus ; the carpus of the left cheliped is devoid of dorsolateral spines (except for a spine on the dorsodistal margin) in C. karubar , whereas there are two or more dorsolateral spines in C. cristimanus . Furthermore, the cornea of the ocular peduncle is not inflated in C. karubar unlike in C. cristimanus ; the mesial faces of the dactyli of the second pereopods are each armed with an additional row of thick bristle-like setae adjacent to the ventral corneous spines in C. cristimanus , but such bristle-like setae are absent in C. karubar . In addition, the lateral margin of the male right chela is lamellar in C. cristimanus , rather than non-lamellar (though still carinate) in C. karubar . Finally, in C. cristimanus , the right sexual tube is directed anterolaterally from the right to the left across the ventral body surface and overreaches the lateral margin of the left coxa by more than half length of the tube, whereas it is short, directed mesially, but not reaching the lateral margin of the left coxa in C. karubar .

Figures

Fig. 15. Catapaguroides karubar McLaughlin, 1997, male (sl 1.0 mm), PANGLAO 2004, stn T39, ZRC 2012.1094. A, shield and cephalic appendages, dorsal view; B, ischium-basis of left third maxilliped, ventral view; C, distal three segments of left fourth pereopod, lateral view; D, sixth thoracic sternite, ventral view; E, coxae of fifth pereopods and eighth thoracic sternite, ventral view; F, telson, dorsal view. Scale bars = 0.5 mm (A); 0.25 mm (B–F).

Fig. 16. Catapaguroides karubar McLaughlin, 1997, male (sl 1.0 mm), PANGLAO 2004, stn T39, ZRC 2012.1094. A, right cheliped, mesial view; B, same, lateral view; C, same, chela, dorsal view; D, same, carpus, dorsal view; E, left cheliped, mesial view; F, same, lateral view (setae omitted); G, same, chela and carpus, dorsal view. Scale bar = 0.5 mm.

Fig. 17. Catapaguroides karubar McLaughlin, 1997, male (sl 1.0 mm), PANGLAO 2004, stn T39, ZRC 2012.1094. A, right second pereopod, lateral view; B, same, dactylus, mesial view; C, left third pereopod, lateral view; D, same, dactylus, mesial view (dorsal setae partially omitted). Scale bars = 0.5 mm.