Calocarcinus africanus Calman, 1909

Ahyong, Shane T., 2009, First records of Thryaplax Castro, 2007 and Calocarcinus Calman, 1909 (Crustacea: Decapoda: Brachyura) from the Kermadec Islands, New Zealand, Zootaxa 1982, pp. 66-68 : 66-68

Calocarcinus africanus Calman, 1909

( Fig. 1 D)

Calocarcinus africanus Calman, 1909: 31 , unnumbered figure [type locality: between Aden and Zanzibar, 1098 m].

Material examined. NIWA 41723, 1 juvenile female (cl 3.8 mm, cw 4.9 mm), off Curtis Island, Kermadec Islands, 30°17.59’S, 178°25.30’W, 398–412 m, stn K840, 28 Jul 1974.

Remarks. The specimen is a juvenile female, having a narrow male-like abdomen with a functioning abdominal locking mechanism, and rudimentary gonopores. Although only a juvenile, the specimen is identified with C. africanus based on its relatively short cheliped merus that does not extend markedly beyond the anterolateral margins of the carapace. Note that in the key to species of Calocarcinus given by Castro et al. (2004: 58), the couplets were inadvertently transposed, each leading to the incorrect species name. Plate 4C of Castro el al. (2004), however, correctly depicts adult Calocarcinus africanus .

As with Thyraplax truncata , the present specimen represents the first record of the genus and species from New Zealand waters. Three other species of trapeziid are known from the Kermadec Islands; all are species of Trapezia , which live amongst the branches of shallow water Scleractinia , principally species of Pocillopora ; Takeda & Webber 2006). Calocarcinus africanus , however, is a deep water species associated with antipatharian, alcyonacean, gorgonian and ahermatypic scleractinian corals ( Castro et al. 2007).

Distribution. Western Indian Ocean to the western Pacific including New Caledonia, the Norfolk Ridge, and now from the Kermadec Islands, New Zealand; 183–1098 m ( Galil & Clark 1990).

Figures

FIGURE 1. A – C, Thyraplax truncata Castro, 2007, female (cl 9.0 mm, cw 12.0 mm), NIWA. D, Calocarcinus africanus Calman, 1909, juvenile female (cl 3.8 mm, cw 4.9 mm), NIWA. A, D, dorsal view. B, right female gonopore. C, right maxilliped 3. Scale: A = 3.0 mm, B = 1.5 mm, C = 0.6 mm, D = 0.8 mm.