Cryptopilumnus taiwanensis, Hsueh & Huang & Ng, 2009

Hsueh, Pan-Wen, Huang, Jung-Fu & Ng, Peter K. L., 2009, On a new genus and new species of pilumnid crab from Taiwan, and the generic placements of Heteropanope changensis (Rathbun, 1909) and Pilumnopeus pereiodontus Davie and Ghani, 1993 (Crustacea: Decapoda: Brachyura), Journal of Natural History 43 (5 - 6), pp. 323-334 : 326-333

publication ID	https://doi.org/ 10.1080/00222930802585802
persistent identifier	https://treatment.plazi.org/id/8D7D8783-FA76-FF89-E1BE-2D10915530E2
treatment provided by	Carolina
scientific name	Cryptopilumnus taiwanensis
status	sp. nov.

Treatment

Cryptopilumnus taiwanensis View in CoL sp. nov.

( Figures 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 A–D)

Material examined

Holotype male (4.5 by 3.0 mm) ( NMNS5771-001 View Materials ), Sunsheintai (23 ° 06.899 9 N, 121 ° 24.012 9 E), Taitung County, coll. P.-W. Hsueh, 6 May 2005 . Paratypes: 1 female (3.5 by 1.9 mm) ( NMNS5771-002 View Materials ), same data as holotype ; 1 male (3.8 by 2.7 mm) ( NMNS5771-002 View Materials ), Shihmen (25 ° 17.84 9 N, 121 ° 34.23 9 E), Taipei County , coll. P.-W. Hsueh, 1 November 2003 ; 3 males (4.4 by 3.2 mm, 4.4 by 2.7 mm, 3.8 by 2.2 mm), 3 females (3.4–5.0 by 2.2–3.3 mm) ( ZRC 2008.0496 View Materials ), Sunsheintai (23 ° 06.899 9 N, 121 ° 24.012 9 E), Taitung County, coll. P.-W. Hsueh, 20 May 2005 ; 2 males (3.8 by 2.7 mm, 3.4 by 2.4 mm) ( NMNS5771-003 View Materials ) , 3 females (2 ovigerous; 4.0–4.6 by 3.0– 3.4 mm) ( NMNS5771-004 View Materials ), Shihmen (25 ° 17.84 9 N, 121 ° 34.23 9 E), Taipei County , coll. P.- W. Hsueh, 1 November 2003 ; 5 males, 4 females, 1 juvenile, Sunsheintai (23 ° 06.899 9 N, 121 ° 24.012 9 E) ( ZRC 2008.0497 View Materials ), Taitung County, coll. P.-W. Hsueh, 14 October 2007 ; 2 males, 2 females, Wunlitung (21 ° 59.44 9 N, 121 ° 42.16 9 E) ( QM W28477), Pingtung County, southern Taiwan, lower intertidal coral reefs, coll. P.-W. Hsueh, 15 December 2007 . All localities are in Taiwan .

Diagnosis

Carapace with regions almost smooth; suborbital margin lined with small rounded granules; with three low granular lobes, separated from low external orbital tooth by a depression; outer surface of chelae covered with numerous granules and setae; ischium of P4, P5 with five to nine short comb-like tubercles ventrally; ventral margins of P4, P5 with prominent tubercles proximally, that of P5 with 10–12 small and large tubercles on outer margin; G1 slender, S-shaped.

Description

Carapace ovoid, about 1.5 times as broad as long ( Figures 3A View Figure 3 , 4A View Figure 4 ); regions poorly defined, surface without distinct granules, areas around lateral margins minutely granular; setae scattered on poorly defined frontal, epigastric, protogastric, hepatic and branchial regions; front broadly bilobed, median lobes separated by median cleft, margins gently convex to almost straight; lateral lobule low but visibly demarcated from median lobes by small notch, margins uneven but unarmed, about half carapace width ( Figures 3A View Figure 3 , 4A View Figure 4 ); eye moveable, suborbital margin lined with small rounded granules, without tooth, spine or fissure; orbital hiatus distinct, basal antennal segment mobile, antennae lodged inside orbit; supraorbital margin lined with scattered very small granules, without fissure; anterolateral margin arcuate, convex, with three very low lobes (excluding low external orbital tooth), which may be almost indiscernible, first lobe barely separated from external orbital tooth by depression, third lobe lowest and smallest, margins lined with small granules but not spinules; posterolateral margins distinctly converging towards gently sinuous posterior carapace margin, lined with minute granules ( Figure 3A View Figure 3 ). Pterygostomial, subhepatic, suborbital regions covered with minute granules and dense short setae. Endostomial ridges distinct. Third maxilliped quadrate; merus about 1.6 times broader than long, distinctly smaller than ischium; ischium rectangular, without median sulcus, inner margin gently denticulate, about 1.2 times longer than broad; palp (dactylus, propodus and carpus) short, articulates at inner corner of merus; exopod stout, with distinct flagellum ( Figure 4C View Figure 4 ).

Both male and female chelipeds asymmetrical ( Figure 3A,B View Figure 3 ); ischium short, inner margin granular; merus with granular inner margin, without obvious distal tooth; outer surface of carpus granular, with low, rounded inner-distal tooth; chela prominent teeth present at base of fingers, prominent teeth of mobile and immobile fingers interlocking when closed; palms swollen medially, outer surface of palm with numerous small and large granules, dense setae present on outer surface of palms and carpus ( Figures 3B,C View Figure 3 , 4E View Figure 4 ).

P2–P5 slender; P3 longest; dorsal surface of merus and propodus of the P2–P5 with scattered setae, carpus and dactylus covered with dense setae all around ( Figure 3A,B View Figure 3 ); dorsodistal angle of merus of P2–P5 rounded, not prominently produced; dorsodistal margin of merus of P2–P4 with low granules; ventral margin of ischium of P4 with seven to nine comb-like tubercles, three or four anterior spines larger, posterior ones smaller, proximal part of ventral margin of merus denticulate; P5 less setose, ischium with five to seven small comb-like tubercles distally on ventral margin, ventral margin of merus with three or four larger tubercles proximally, followed by seven to nine smaller tubercles on both left and right margins, becoming gradually reduced in size toward the distal end, tubercles on outer margin stronger than those along inner margin; carpus short, unarmed; dactylo-propodal lock present; dactylus gently curving inwards, tip corneous ( Figure 3D View Figure 3 ).

Thoracic sternites smooth; sternites 1 to 3 completely fused without trace of sutures, sternites 3 and 4 separated by incomplete sutures, with only lateral parts visible; male sterno-abdominal cavity extending to about half the length of sternite 4 ( Figures 3B View Figure 3 , 4B View Figure 4 ). Male abdomen with all somites (including telson) freely articulating; somite 3 laterally expanded, completely covering sternite 8 when closed; telson triangular, longer than broad, tip rounded ( Figures 3B View Figure 3 , 4F View Figure 4 ). G1 slender, S-shaped; distally pointed, curving outwards ( Figure 5 View Figure 5 A–C); G2 very short, sigmoid ( Figure 5D View Figure 5 ).

Etymology

The species is named after the island where it was found.

Type locality

It is known only from northwestern, southern and eastern coasts of Taiwan.

Habitat

The species has only been found in cracks within sediment rocks in the lower part of the intertidal zone.

Colour of fresh specimen

In life, the dorsal surfaces are dark greenish-black. The meri of the ambulatory legs are generally paler. The ventral surfaces are dirty-white. The setae on the carapace and legs are brown.

Remarks

Cryptopilumnus taiwanensis View in CoL can easily be separated from C. pereiodontus View in CoL by its smoother carapace ( Figures 3A View Figure 3 , 4A View Figure 4 ) (versus distinctly granular, cf. Davie and Ghani 1993, figure 1A), less well-defined and lower anterolateral teeth ( Figures 3A View Figure 3 , 4A View Figure 4 ) (versus relatively more prominent, cf. Davie and Ghani 1993, figure 1A,B); granules on the outer surface of the chela being relatively larger ( Figures 3C View Figure 3 , 4E View Figure 4 ) (versus larger, cf. Davie and Ghani 1993, figure 2C); more strongly armed P4 and P5 which have more tubercles ( Figures 3A View Figure 3 , 4D View Figure 4 ) (versus with only two or three tubercles on P5 while P4 is apparently unarmed, cf. Davie and Ghani 1993, figure 1D); and distal part of the G1 gently curving upwards and more tapering ( Figure 5 View Figure 5 A–C) (versus relatively shorter and not bent, cf. Davie and Ghani 1993, figure 2E). Cryptopilumnus taiwanensis View in CoL can be separated from C. changensis View in CoL by its relatively more setose carapace ( Figure 3A View Figure 3 versus Figure 2A View Figure 2 ), indistinct lobes on the anterolateral margin ( Figures 3A View Figure 3 , 4A View Figure 4 ) (versus low teeth, Figure 1A View Figure 1 , 2A View Figure 2 ), slightly narrower frontal median lobes ( Figures 3A View Figure 3 , 4A View Figure 4 versus Figures 1A View Figure 1 , 2A View Figure 2 ), denser setae on the outer surface of the chela ( Figures 3C View Figure 3 , 4E View Figure 4 versus Figures 1B,C View Figure 1 , 2C View Figure 2 ), relatively shorter ambulatory legs ( Figures 3A View Figure 3 , 4D View Figure 4 versus Figures 1A View Figure 1 , 2A View Figure 2 , 5F View Figure 5 ), ischium of P5 has comb-like tubercles on the ventral margin ( Figure 4D View Figure 4 ) (versus simple tubercles, Figure 5F View Figure 5 ), weaker armature on the ischium and merus of the P4 and P5 with fewer tubercles ( Figure 4D View Figure 4 versus Figure 5F View Figure 5 ), and distal part of the G1 gently curving upwards ( Figure 5 View Figure 5 A–C) (versus gently hooked downwards, Figure 5E View Figure 5 ). The colour of the two species in life are also different; with the dorsal surfaces of C. taiwanensis View in CoL a uniform dark greenish-black compared with brownish-green with clear patches of light green between the regions and ambulatory legs in C. changensis View in CoL .