Camatopsis thula, Ng, Peter K. L. & Castro, Peter, 2016

Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), Zootaxa 4209 (1), pp. 1-182 : 44-45

Camatopsis thula n. sp.

( Figs. 7 C‒F; 23G; 30D; 39E, F; 51D; 58D; 67M‒O; 86D; 90D; 100H)

Camatopsis rubida — Yokoya 1933: 202 [ Japan].— Sakai 1936: 193, pl. 55, fig. 4; 1939: 576, pl. 68, fig. 4; 1965: 173, pl. 85, fig. 4; 1976: 552, pl. 195, fig. 4 [ Japan].— Takeda 1973a: 13; 1973b: 55; 1997: 247 [ Japan].— Fang 1991: 352, 355, fig. 4 [map] [ Taiwan].— Muraoka 1998: 47 [ Japan].—Ng et al. 2001: 34 [in list] [ Taiwan].— Hsueh & Huang 2002: 113, fig. 2A [ Taiwan].— Jiang 2008: 770 [in list] [ Taiwan].— Komai et al. 2012: 149, fig. 6. Not Camatopsis rubida Alcock & Anderson, 1899 .

Type material. Holotype male (8.9 × 9.3 mm) ( ZRC 1999.0662 ), Taiwan, Ilan County, Tashi Fishing Port.

Paratypes: 1 male (9.0 × 10.5 mm) ( ZRC 2009.0347 ), Taiwan, Ilan County, Tahsi Fishing Port, 26.08.2000 ; 1 female (7.3 × 8.2 mm) ( ZRC 2009.0348 ), Ilan County, Tahsi Fishing Port, 01.12.1999 ; 2 females (ZRC 1999.0749), S.H. Wu coll., 02.10.1990; 1 ovigerous female (10.1 × 10.7 mm) (ZRC 1999.752), P.K.L. Ng et al. coll., 15.05.1995; 1 female (ZRC 1998.420), Ilan County, Tashi Fishing Port, S.H. Wu coll., 05.1997; 1 female (8.7 × 9.7 mm) ( ZRC 2015.185 ), Ilan County, Tashi Fishing Port, P. - H. Ho coll., 09.01.1999 ; 1 male (9.9 × 10.8 mm), 1 female (10.2 × 11.1 mm) (ZRC 1999.0751), Ilan County, Tashi Fishing Port, P.K.L. Ng & K. Lim coll., 05.1999; 1 male (10.2 × 11.1 mm) ( ZRC 2001.2215 ), TAIWAN 2001, stn CP77, 24°54.18’N, 122°02.46’E, 360 m.

Other material examined. Japan. 1 male, 1 female ( SMF) [dried], unknown location, T. Sakai collection. — 1 male, 2 females (NSMT-Cr 12101), Suruga Bay , South Senoumi Bank, stn DG96-6, 157– 159 m, 14.11.1996.

Taiwan. 1 male, J.W. Lim coll., 0 5.01.1999 ( ZRC 1999.0750 ).

Diagnosis. Carapace ( Figs. 7 C–F; 100H) subtrapezoidal, 1.0‒1.2 wider than long; front bilobed, with shallow or deep median cleft; anterolateral margins arcuate, carapace minutely granular with granules higher along lateral margins, without distinct lobes or teeth. Eye peduncle ( Fig. 23 G) filling orbit, short, slightly mobile; cornea reduced, with reduced pigmentation. Epistome ( Fig. 23 G), semicircular median lobe with deep median fissure, semicircular lateral margins. Third maxilliped ( Fig. 30 D) merus quadrate, outer margin convex, ischium subquadrate, about same length as merus. Proportionally short ambulatory legs ( Fig. 7 E, F); P5 merus 0.6 cl. Chelipeds ( Figs. 7 E–F; 39E, F; 100H) subequal in length, slightly dissimilar in females, heteromorphic in males. Major chela of males ( Fig. 39 E) with thick propodus, cutting margins with few sharp teeth (arched, proximal, toothless gap in large males). Minor chela of both sexes ( Fig. 39 F) with cutting margin of pollex having 2 long, sharp teeth that overlap dactylus when closed. Inner margin of cheliped carpus smooth. Fused thoracic sternites 1, 2 ( Fig. 51 D) triangular, proportionally narrow, short. Male pleon ( Figs. 51 D; 58D) with proportionally short telson G1 ( Fig. 67 M, N) stout, distal segment slightly curved, distal segment curved inwards towards sternum at approximately right angles, slightly twisted, with short to long spinules. G2 ( Fig. 67 O) about 3/4 G1 length, straight, slender, short distal segment. Female pleon ( Fig. 86 D) with lateral margins of somites strongly convex; telson proportionally short. Sterno-pleonal cavity of female ( Fig. 90 D) moderately deep, vulvae far apart from each other.

Colour. The carapace and pereiopods are light brown in life ( Fig. 100 H).

Etymology. The name is derived from Thoule, Greek for “farthest north”, in reference to the species showing the northernmost extension of all of the species of Camatopsis .

Remarks. Camatopsis thula n. sp. is characterised by possessing the shortest and stoutest ambulatory meri in the genus, and by having a G 1 in which the distal part is sharply bent inwards ( Fig. 67 M, N).

Fang (1991) found C. thula (as C. rubida ) to be the dominant species of brachyuran crab in soft sediments in the Taiwan Strait. Biomass of C. thula and other crab species was higher in finer sediments.

Distribution. Japan and Taiwan. Depth: 65‒660 m ( Sakai 1976).

Figures

FIGURE 7. Overall dorsal view of species of Camatopsis. A, C. africana, Madagascar: holotype male 5.7 × 6.9 mm (MNHN- IU- 2010 - 1574); B, C. africana n. sp., Mozambique Channel: paratype female 9.4 × 11.0 mm (MNHN-IU- 2008 - 10288); C, C. thula n. sp., Taiwan: holotype male 8.9 × 9.3 mm (ZRC 1999.0662); D, C. thula n. sp., Taiwan: paratype female 7.1 × 7.6 mm (ZRC 2009.0348), E, C. thula n. sp., Taiwan: male 9.0 × 10.5 mm (ZRC 2009.347); F, C. thula n. sp., Taiwan: female 7.3 × 8.2 mm (ZRC 2009.348); G, C. valida n. sp., Fiji: holotype male 3.6 × 4.9 mm (MNHN-IU- 2013 - 9067); H, C. valida n. sp., Fiji: paratype female 3.5 × 4.3 mm (MNHN-IU- 2013 - 9467).

FIGURE 23. Frontal view of cephalothorax of species of Camatopsis and Chasmocarcinops. A, Camatopsis rubida, Andaman Sea: male 4.2 × 4.5 mm (ZMUC CRU 20539); B, Camatopsis rubida, Australia: male 8.3 × 8.5 mm (NMV J 54591); C, Camatopsis africana n. sp., Madagascar: holotype male 5.7 × 6.9 mm (MNHN-IU- 2010 - 1574); D, Camatopsis leptomerus n. sp., Philippines: holotype male 10.5 × 11.3 mm (NMCR); E, Camatopsis leptomerus n. sp., Philippines: paratype female 3.4 × 4.0 mm (ZRC 2015.159); F, Camatopsis minor n. sp., Indonesia: holotype male 3.6 × 4.3 mm (NNM-ZMA); G, Camatopsis thula n. sp., Taiwan: holotype male 8.9 × 9.3 mm (ZRC 1999.0662); H, Camatopsis valida n. sp., Fiji: holotype male 3.6 × 4.9 mm (MNHN-IU- 2013 - 9067); I, Chasmocarcinops gelasimoides, Andaman Sea: male 8.8 × 9.5 mm (PMBC 16849); J, Chasmocarcinops gelasimoides, Singapore: male 9.5 × 10.3 mm (ZRC 2000.1341).

FIGURE 30. Third maxilliped of species of Camatopsis and Chasmocarcinops. A, Camatopsis rubida, Australia: male 8.3 × 8.5 mm (NMV J 54591); B, Camatopsis africana n. sp., Madagascar: holotype male 5.7 × 6.9 mm (MNHN-IU- 2010 - 1574); C, Camatopsis leptomerus n. sp., Philippines: holotype male 10.5 × 11.3 mm (NMCR); D, Camatopsis thula n. sp., Taiwan: holotype male 8.9 × 9.3 mm (ZRC 1999.0662); E, Chasmocarcinops gelasimoides, Andaman Sea: male 8.8 × 9.5 mm (PMBC 16849); F, Chasmocarcinops gelasimoides, Singapore: male 9.5 × 10.3 mm (ZRC 2000.1341).

FIGURE 39. Chelae of species of Camatopsis. A, B, C. leptomerus n. sp., Philippines: holotype male 10.5 × 11.3 mm (NMCR); C, D, C. leptomerus n. sp., Philippines: paratype female 3.4 × 4.0 mm (ZRC 2015.159); E, F, C. thula n. sp., Taiwan: holotype male 8.9 × 9.3 mm (ZRC 1999.0662); G, H, C. minor n. sp., Indonesia: holotype male 3.6 × 4.3 mm (NNM-ZMA); I, J, C. valida n. sp., Fiji: holotype male 3.6 × 4.9 mm (MNHN-IU- 2013 - 9067).

FIGURE 51. Anterior thoracic sternum and male pleon of species of Camatopsis and Chasmocarcinops. A, Camatopsis rubida, Australia: male 8.3 × 8.5 mm (NMV J 54591); B, Camatopsis africana n. sp., Madagascar: holotype male 5.7 × 6.9 mm (MNHN-IU- 2010 - 1574); C, Camatopsis leptomerus n. sp., Philippines: holotype male 10.5 × 11.3 mm (NMCR); D, Camatopsis thula n. sp., Taiwan: holotype male 8.9 × 9.3 mm (ZRC 1999.0662); E, Camatopsis valida n. sp., Fiji: holotype male 3.6 × 4.9 mm (MNHN-IU- 2013 - 9067); F, Chasmocarcinops gelasimoides, Singapore: male 9.5 × 10.3 mm (ZRC 2000.1341).

FIGURE 67. Gonopods of species of Camatopsis. A ‒ C, C. rubida, Andaman Sea: male 4.2 × 4.5 mm (ZMUC CRU 20539); D ‒ F, C. rubida, Australia: male 8.3 × 8.5 mm (NMV J 54591); G ‒ I, C. africana n. sp., Mozambique Channel: holotype male 6.8 × 7.7 mm (MNHN-IU- 2010 - 1500); J ‒ L, C. leptomerus n. sp., Philippines: holotype male 10.5 × 11.3 mm (NMCR); M ‒ O, C. thula n. sp., Taiwan: holotype male 8.9 × 9.3 mm (ZRC 1999.0662). A, B, D, E, G, H, J, K, M, N, ventral view of left G 1; F, dorsal view of left G 1; C, I, L, O, left G 2. Scales: A, C, D, G, I, J, L, M, O = 0.5 mm; B, E, F, H, K, N = 0.1 mm.

FIGURE 86. Female thoracic sternum and pleon of species of Camatopsis and Chasmocarcinops. A, Camatopsis rubida, Australia: female 6.0 × 7.0 mm (NMV J 61082); B, Camatopsis africana n. sp., Mozambique Channel: paratype female 9.4 × 11.0 mm (MNHN-IU- 2008 - 10288); C, Camatopsis leptomerus n. sp., Philippines: paratype female 12.7 × 13.2 mm (ZRC 2015.170); D, Camatopsis thula n. sp., Taiwan: paratype female 7.1 × 7.6 mm (ZRC 2009.0348); E, Camatopsis minor n. sp., Indonesia: paratype female 4.0 × 4.9 mm (NNM-ZMA); F, Chasmocarcinops gelasimoides, Singapore: female 9.3 × 10.6 mm (ZRC 2013.1411).

FIGURE 90. Vulvae of species of Camatopsis and Chasmocarcinops. A, Camatopsis rubida, Australia: female 6.0 × 7.0 mm (NMV J 61082); B, Camatopsis africana n. sp., Mozambique Channel: paratype female 9.4 × 11.0 mm (MNHN-IU- 2008 - 10288); C, Camatopsis leptomerus n. sp., Philippines: paratype female 12.7 × 13.2 mm (ZRC 2015.170); D, Camatopsis thula n. sp., Taiwan: paratype female 7.1 × 7.6 mm (ZRC 2009.0348); E, Camatopsis valida n. sp., Fiji: paratype female 3.5 × 4.3 mm (MNHN-IU- 2013 - 9467); F, Chasmocarcinops gelasimoides, Singapore: female 9.3 × 10.6 mm (ZRC 2013.1411).

FIGURE 100. Chasmocarcinus and Camatopsis. A, B, Chasmocarcinus longipes, Taboga, Panama: male (not examined) [A. Anker]; C, Camatopsis africana n. sp., Madagascar: paratype female 8.3 × 9.8 mm (MNHN-IU- 2008 - 10286) [T. - Y. Chan]; D, Camatopsis africana n. sp., Madagascar: paratype female 5.6 × 6.2 mm (MNHN-IU- 2008 - 10287) [T. - Y. Chan]; E, Camatopsis leptomerus n. sp., Philippines: male 5.2 × 4.5 mm (ZRC 2015.129) [P. K. L. Ng]; F, Camatopsis leptomerus n. sp., Vanuatu: female 7.2 × 7.9 mm (ZRC 2015.173) [J. C. Mendoza]; G, Camatopsis leptomerus n. sp., Vanuatu: female 9.5 × 10.1 mm (ZRC 2015.168) [T. - Y. Chan]; H, Camatopsis thula n. sp., Taiwan: paratype male 10.2 × 11.1 mm (ZRC 2001.2215) [T. - Y. Chan].