Calappa africana, Lai, Joelle C. Y. & Ng, Peter K. L., 2006

Lai, Joelle C. Y. & Ng, Peter K. L., 2006, A new species of Calappa Weber, 1795 (Crustacea: Decapoda: Calappidae) from East and South Africa, Zootaxa 1358, pp. 39-48 : 40-47

Calappa africana , new species

Figs. 1A –D, 2A, B, 3A, 4

Calappa japonica — Barnard, 1947: 372; 1950: 352, figs. 66 n–p; Kensley, 1981: 38 (list); Galil, 1997: 301 (part) (not Calappa japonica Ortmann, 1892 ).

Material examined: Holotype: male (81.2 by 109.7 mm) ( USNM 268804), station 442, Somalia, off northeast coast. 9º33’N 50º59’E, trawled at 70–80m depth, coll. R/V Anton Bruun cruise no 9, 16 December 1964. Paratypes: 1 female (80.5 by 105.8 mm) ( ZRC 2006.0109), South Africa, Eastern Cape, Port Elizabeth, Bay World, off Kenton, coll. S. Warren, June 2004; 1 male (84.2 by 126.3 mm) ( RMNH 30335), Kenya, Mombasa, coll. A. J. Bruce, 1974.

Comparative material: Calappa japonica Ortmann 1892 : TAIWAN: 1 male (97.8 by 138.8 mm) ( ZRC 1999.726) South Taiwan: Kaohsiung County, Tungkang Fish Port coll. P. K. L. Ng May 1999; 2 males (93.7 by 130.6 mm, 98.8 by 140.7mm), 1 female (104.6 by 145.2 mm) ( ZRC 2001.0002) S. Taiwan: Kaohsiung County, Tungkang Fish Port coll. P.K.L. Ng 7 Nov 2000; 1 male (102.4 by 145.3 mm) ( ZRC 1998.204) North-East Taiwan, I-Lan County, Tai-Chi Fish Port, commercial inshore trawlers about 100– 400m. coll. P. K. L. 0 3–0 4 Aug 1996. PHILIPPINES: 1 juvenile male (25.9 by 31.2mm) ( ZRC 2006.0112), Bohol, Panglao, Balicasag Is., from tangle nets, coll. local fishermen, June 2004; 1 male (52.3 by 68.3 mm), 1 female (37.0 by 46.2 mm), 2 juveniles (larger 18.2 by 21.5 mm) ( ZRC 2002.0464), 1 male (carapace length 36.7 mm, sides damaged) ( ZRC 2002.465), Bohol, Panglao, Balicasag Is., from tangle nets, coll. local fishermen, Jul 2002; 1 female (74.6 by 100.1 mm) ( ZRC 2006.0113), Bohol, Panglao, Balicasag Is., from tangle nets, coll. local fishermen 29 May 2004. PAKISTAN: 1 male (39.5 by 52.6 mm) ( ZMUC Cru 1846), 24°50’N, 61°52’E, Mekran, 135–148m, coll. P. Hansen, 25 Nov 1963. INDIA: Bay of Bengal, 1 male (lectotype of Calappa exanthematosa Alcock & Anderson, 1894 ) (58.4 by 80.5 mm) (NHM 1896.9.8.8), 1 male (paralectotype of Calappa exanthematosa Alcock & Anderson, 1894 ) (35.3 by 46.4 mm) ( ZMUC) (Indian Museum label 9/1899), West Coast of Indian Subcontinent, 17°27’N, 71°41’E, 56–58 fathoms

Diagnosis. Carapace dorsal surface with anterior half granulate to tuberculate, covered with round sub-mammillate knob- or pustule-like tubercles; posterior half smooth, small granules along posterior margin. Anterolateral margin with 12 protuberances, last 6 more distinct than first 6. Posterolateral margin of clypeiform expansion with 7 teeth, first 4 pointing laterally outwards with the first tooth being the smallest; last 3 teeth of posterolateral margin directed posteriorly, lacinate, sharp with median longitudinal ridge. Posterior margin bound by 2 triangular teeth, flanking abdomen, coarsely granulated, faintly convex. Basal antennal segment with distal margin notched. Endostomial septum appears truncated at distal end, not visible when viewed from the anterior with third maxillipeds closed. Outer surface of manus granulated, larger rounded submammillate tubercles on surface of dorsal third. G1 thick, stout, slightly sinuous; tip truncate, distal surface lined with numerous minute spinules. G2 subequal in length to G1, slender, curved, distal tip rounded.

Description. Carapace oval (1.35 times as wide as long). Dorsal surface distinctly convex, anterior two-thirds covered with large, round submammillate tubercles, resembling pustules; posterior third smooth, minutely granular along posterior margin. Gastric region swollen, with median part highest point of carapace. Frontal margin with 2 rounded knobs, separated by wide sulcus. Supraorbital margin unevenly granular, with 2 narrow longitudinal fissures. Eyes folded obliquely, external orbital tooth rounded. Anterolateral margin arcuate, carinate, tuberculate, with 12 blunt, rounded unevenly sized tubercles; last 6 tubercles better defined than first 6. Posterolateral margin of clypeiform expansion well developed, with 7 triangular teeth, each tooth with denticulate margins and longitudinal median ridge; first anterior tooth smallest; second, third subequal; fifth, sixth, seventh pointing posteriorly; fifth subequal to fourth; sixth, seventh teeth subequal. Posterior margin of carapace with 2 teeth, each with gently serrated margins; flanking the abdomen. Posterior margin gently convex, coarsely granulated. Basal antennal segment subtriangular, smooth with median ridge; distal margin notched. Longitudinal epistomial septum appears truncated at anterior end, not visible when third maxillipeds closed.

Minor left chela (without cutting tooth) with distinct, prominent dorsal crest; 6 lamelliform teeth, first blunt, low, subsequent 5 acutely triangular, sharp; outer surface of manus uniformly granulated throughout, density highest near base of crest and lower onethird near ventral margin; upper half of manus with several large mammilliform tubercles; ventral margin of manus lined with rows of laterally directed granules, with distinctive triangular tooth on proximal edge of ventral margin; dactylus slender, curved, proximal half granulated, distal half pigmented smooth, fringed with setae. Major right chela (with distinct cutting tooth) similar in shape to minor chela, except dactylus pigmented on inner edge. Pollex with 3 squamose molariform teeth, first tooth largest, subsequent teeth gradually smaller.

Ambulatory legs slender, smooth, laterally flattened. Dactylus styliform, gently curved. Abdomen narrow; first segment narrow with slightly convex granulated outer margin; second segment with distinct granules on outer and median parts; third to fifth segment fused but lateral clefts separating them still discernable; third segment subrectangular, outer margin granulated, scalloped; fourth segment trapezoidal, lateral margins slightly concave; fifth segment rectangular, lateral margins slightly concave; sixth segment squarish, lateral margins sinuous; telson acutely triangular, lateral margins straight, converging to sharp apex distally.

G1 stout, slightly sinuous; tip truncated, distal surface lined with numerous minute spinules. G2 subequal in length to G1, slender, curved, distal tip rounded.

Remarks. Barnard’s (1947, 1950) reports of Calappa japonica were the first from South Africa. His record was followed by that of Kensley (1981) in a list of the South African decapod crustaceans. Galil (1997), in her revision of the genus, followed Barnard (1950) and Kensley (1981), and listed the species from South Africa. The South African specimens examined here are certainly similar to C. japonica ( Ortmann, 1892) , but can be differentiated by several diagnostic differences, most notably life colouration, carapace physiognomy, spinal structure in the distal margin of the merus, features associated with the cheliped, manus and G1 morphologies.

The live and/or freshly preserved colours of C. japonica and C. africana , new species, are markedly different. The dorsal carapace surface of C. japonica is uniformly orange or dark yellow, with the anterior two-thirds covered with numerous large and smooth tubercles, each of which has a red ring at the base and is coloured bright yellow medially and at the apex ( Fig. 1 E). The posterior third of the carapace is smooth, unarmed, and marked with numerous red spots (but without the yellow marks) in the branchial region (see also Sakai, 1976: pl. 40 fig. 2; Miyake, 1983: pl. 7 fig. 5). Thus, while only the anterior two-thirds of the carapace of C. japonica is actually tuberculate, the presence of the distinctly coloured spots on the posterior one-third of the carapace gives individuals the illusion of being far more granular than they really are ( Figs. 1 E, 2C, D). In the freshly preserved paratype of C. africana (ZRC), the dorsal surface of the carapace is beige to light brown in colour, speckled with salmon pink to light red mottles. Large, smooth tubercles are also present on the anterior half of the carapace, but they do not possess the characteristic colouration of those on C. japonica ( Fig. 1A , C, 2A, B). Overall, C. africana , has fewer and lower granules, especially on the median and anterolateral surfaces ( Fig. 1A , C).

Barnard’s (1950: 352) colour description of C. japonica is diagnostic: “ As preserved, pale with salmon pink mottling around the pustules and on hinder half of the carapace.” This colour exactly matches our observations on C. africana , new species. Barnard’s description and figure of the carapace also match the new species. Thus, we consider his record to represent C. africana .

The physiognomies of the two species are quite different. The branchial regions of C. japonica ( Fig. 2 C, D) being relatively more swollen than those of C. africana ( Fig. 2 A, B). This is especially obvious when viewed frontally with specimens of similar size and belonging to the same sex. Together with the more prominent and extensive tubercles on the carapace surface, the overall appearance of C. japonica is more convex and rounded ( Fig. 1A , C, 2A, B) than in the new species ( Fig. 1 E, 2C, D). It is known that the carapaces of female Calappa specimens are generally more rounded and swollen compared to males (see Ng et al., 2002; Ng, 1993; Lai et al., 2006), but the differences in carapace physiognomy between C. japonica and C. africana are so marked that they are even apparent between sexes for the two species.

The external surface of the manus of the cheliped is also different in the two species.

In C. africana , there are numerous small granules uniformly distributed throughout the entire manus between the larger tubercles ( Fig. 1B , D) while in C. japonica , the fine granules are gently scattered between the large round tubercles which are similarly coloured to those on the carapace, with the ventral third of surface of the manus smooth ( Fig. 1 F). The spines of the external margin of the merus also differ significantly between the two species. In C. africana , the margin consists of four lacinate teeth (fig. 3A) while in C. japonica , the distal margin of the merus consists of four lobes, each with a small tooth protruding from the centre of the lobe ( Fig. 3 B). The G1 structure of C. africana differs from that of C. japonica in the shape of its basal portion, being straighter and slightly more sinuous ( Fig. 4 A).

The holotype specimen of C. africana (USNM 268804) was examined by the late Austin B. Williams. While he identified it as C. japonica , he commented (in a note preserved with the specimen) that it did not resemble C. japonica collected from the Gulf of Aden. The bottle with this specimen was kept in a separate section of the USNM, and only discovered when the second author and the present curator, Rafael Lemaitre, were looking for some other calappid specimens. One paratype specimen (RMNH 30335) was collected from Kenya, and was briefly examined by the second author at RMNH in 2005. Charles H.J.M. Fransen was kind enough to subsequently take a good series of photographs for us to confirm that it is not C. japonica as it was originally identified but C. africana instead. This RMNH specimen was included in Galil’s (1997: 301) revision as C. japonica .

The large series of specimens of C. japonica s. str. from the Indian and Pacific oceans that was examined shows that the differences between this species and C. africana are not due to geographical variation or are related to size or sex. We also examined two syntype specimens of Calappa exanthematosa Alcock & Anderson, 1894 , which has long been regarded as a junior subjective synonym of C. japonica (see Galil, 1997: 300). We concur with this synonymy. Both syntype specimens (NHM 1896.9.8.8; ZMUC) have all the characters we here associate with C. japonica s. str. The availability of small specimens of C. japonica from the Philippines (ZRC 2002.0464, ZRC 2002.465) confirms this. For stability, we here designate the better male specimen (NHM 1896.9.8.8) as the lectotype of C. exanthematosa Alcock & Anderson, 1894 . The ZMUC specimen therefore becomes a paralectotype.

Calappa africana , new species, is the third western Indian Ocean species of Calappa described in recent years that has a close relative ( C. japonica ) with a more easterly distribution, which includes the western Pacific. Calappa guerini Brito-Capello, 1871 , from the western Indian Ocean is closely allied to C. lophos ( Herbst, 1782) , which occurs throughout the western Pacific, Southeast Asia to the eastern Indian Ocean, but with a doubtful record from East Africa ( Lai et al., 2006). Calappa acutispina Lai, Chan & Ng, 2006 , from Madagascar is allied to C. quadrimaculata Takeda & Shikatani, 1990 , from E ast Asia and the Philippines ( Lai et al., 2006; Ng et al., 1999).

Etymology. The species is named after the continent it is known from.

Distribution. Known only off the eastern and southeastern coast of Africa.

Figures

FIGURE 2. Frontal views. Calappa africana, new species: A, male holotype (81.2 by 109.7 mm) (USNM 268804); B, female paratype (80.5 by 105.8 mm) (ZRC 2006.0109); Calappa japonica: C, male (94.24 by 131.3 mm) (ZRC 2001.002); D, female (74.6 by 100.1 mm) (ZRC 2006.0113).

FIGURE 3. External margin of merus of left cheliped. A, Calappa africana, new species, male holotype (81.2 by 109.7 mm) (USNM 268804); B, Calappa japonica, female (74.6 by 100.1 mm) (ZRC 2006.0113).

FIGURE 4. Calappa africana, new species, male holotype (81.2 by 109.7 mm) (USNM 268804). A, left G 1; B, distal part of left G 1; C, left G 2; D, abdomen; E, first article of antenna. Scale: 1 mm

FIGURE 1. A, B, Calappa africana, new species, male holotype (81.2 by 109.7 mm) (USNM 268804); C, D, Calappa africana female paratype (80.5 by 105.8 mm) (ZRC 2006.0109); E, F, Calappa japonica, female (74.6 by 100.1 mm) (ZRC 2006.0113). A, C, E, dorsal view of carapace; B, D, F, left cheliped, external surface.