Carcinoplax ischurodous ( Stebbing, 1923 )

Castro, Peter, 2007, A reappraisal of the family Goneplacidae MacLeay, 1838 (Crustacea, Decapoda, Brachyura) and revision of the subfamily Goneplacinae, with the description of 10 new genera and 18 new species, Zoosystema 29 (4), pp. 609-774 : 635

Carcinoplax ischurodous ( Stebbing, 1923)

Geryon ischurodous Stebbing, 1923: 2 , pl. 11 [ South Africa]. — Barnard 1950: 292, fig. 54 k [ South Africa]. — Manning & Holthuis 1987: 59 [in list].

Carcinoplax eurysternum Guinot & Richer de Forges, 1981a: 1113 , pl. 6, figs 5, 5a, 5b (nomen nudum); 1981b: 249, figs 9E, 10A-D, pl. 6, fig. 5, 5a, 5b [ Vanuatu]. — Guinot 1989: 314 [in list], fig. 44, pl. 13, fig. F [ Vanuatu].

Carcinoplax ischurodous – Manning & Holthuis 1988: 78, fig. 1 [discussion] [ South Africa].

TYPE MATERIAL. — Geryon ischurodous Stebbing, 1923 : ♂ holotype cl 16 mm, cw 26 mm ( BMNH 1928.12. I.104).

Carcinoplax eurysternum Guinot & Richer de Forges, 1981 : ♂ holotype, cl 31.7 mm, cw 47.0 mm ( MNHN-B 6835).

TYPE LOCALITY. — Geryon ischurodous : South Africa, Durban, 29°51’S, 31°01’E, “from a coral on the beach” ( Stebbing 1923: 2).

Carcinoplax eurysternum : Vanuatu, Loh Toga I., Torres Is, 600 m., A. Intès coll.

MATERIAL EXAMINED. — Seychelles. CEPROS, stn 1.3, 04°08’S, 56°11.3’E, trap, 580- 550 m, 20.X.1987, 1 ♂ ( MNHN-B 19109). — Transect 2, trap, 800 m, A. Intès coll., 21-22.X.1987, 1 ♂ ( MNHN-B 19101). — Stn 4.21, 04°45.6’S, 56°38.9’E, trap, 590-620 m, 23.X.1987, 1 ♂, 1 ♀ ( MNHN-B 19111).

Solomon Islands. SALOMON 2, stn CP 2184, 08°16.9’S, 159°59.7’E, 464-523 m, 23.X.2004, 1 ♀ ( MNHN-B 30067). — Stn CP 2213, 07°38.7’S, 157°42.9’E, 495- 650 m, 26.X.2004, 1 ♂ ( MNHN-B 30099). — Stn CP 2248, 07°42.5’S, 156°24.8’E, 650-673 m, 1.XI.2004, 1 ♀ ( MNHN-B 30098).

Vanuatu. Loh Toga I., Torres Is, 600 m., A. Intès coll., ♂ holotype of C. eurysternum ( MNHN-B 6835).

BOA 1, stn CP 2462, 16°37.5’S, 167°57.4’E, 618-641 m, 13.IX.2005, 1 ♂ ( MNHN-B 30090). — Stn CP 2471, 16°22.8’S, 167°50.4’E, 591-627 m, 14.IX.2005, 1 preadult ♀ ( MNHN-B 30131).

New Caledonia. BIOCAL, stn DW 106, 21°35.82’S, 166°29.26’E, 650 m, 8.IX.1985, 1 ♂ ( MNHN-B 16571).

BIOGOECAL, stn CP 232, 21°33.81’S, 166°27.07’E, 760-790 m, 12.IV.1987, 1 ♀ ( MNHN-B 20619).

BATHUS 1, stn CP 663, 20°58.7’S, 165°38.3’E, 730- 780 m, 13.III.1993, 1 ♂ ( MNHN-B 29357). — Stn CP 709, 21°41.78’S, 166°37.88’E, 650-800 m, 19.III.1993, 1 ♀ ( MNHN-B 29306).

BATHUS 3, stn CC 848, 23°02’S, 166°53’E, 680-700 m, 1.XII.1993, 1 ♀ ( MNHN-B 29305).

Tonga. BORDAU 2, stn CP 1528, 21°14’S, 174°59’W, 587- 592 m, 3.VI.2000, 2 ovig. ♀♀ ( MNHN-B 29370). — Stn CP 1640, 21°09’S, 175°24’W, 564-569 m, 21.VI.2000, 1 ♂, 1 ♀, 1 pre-adult ♀ ( MNHN-B 29553).

DISTRIBUTION. — Across the Indo-West Pacific region from South Africa ( Barnard 1950) to the southwestern Pacific Ocean ( Guinot & Richer de Forges 1981a). Recorded here for the first time from the Seychelles, Solomon Is, New Caledonia, and Tonga. Depth: 464- 800 m.

REMARKS

Carcinoplax ischurodous is unique among the species of Carcinoplax sensu stricto in having only one anterolateral tooth on each side of the rounded carapace. The outer orbital angle, however, is in the form of an acute, anteriorly-oriented tooth. A round carapace with small or no anterolateral teeth at all is restricted to large specimens of C. indica , C. longimana , C. monodi , and C. purpurea . Nevertheless, a relatively narrow male abdomen, slender and thin G1, greatly expanded vulva, and absence of a vulvar cover clearly establish the inclusion of C. ischurodous in Carcinoplax (see Manning & Holthuis 1988). Guinot (1989: 314) included the species (as C. eurysternum ) in a list of eight “non-revised” species of Carcinoplax in which only C. ischurodous proved not to belong to other genera.