Homolomannia sibogae Ihle, 1912

Forges, Bertrand Richer De & Ng, Peter K. L., 2008, New western Pacific records of Homolidae De Haan, 1839, with descriptions of new species of Homolochunia Doflein, 1904, and Latreillopsis Henderson, 1888 (Crustacea: Decapoda: Brachyura), Zootaxa 1967, pp. 1-35 : 11-14

Homolomannia sibogae Ihle, 1912

( Figs. 9A–C, 10A–C)

Homolomannia sibogae Ihle, 1912: 208 ; 1913: 69, pl. 3, fig. 16–18. — Serène & Vadon 1981: 121. — Guinot & Richer de Forges 1981: 555. — Guinot & Richer de Forges 1995: 460, fig. 63b. — Tan et al. 2000: 183. — Ng et al. 2001: 6. — Richer de Forges & Ng 2007: 41, fig. 8C, D. — Takeda & Manuel-Santos 2007: 88, fig. 9C. — Ng et al. 2008: 40.

Material examined. Solomon Islands: SALOMONBOA cruise, stn. CP 2828, 10°27.40’S 161°58.76’E, 173–379 m, 20 September 2007: 1 female (16.6 x 12.8 mm) ( MNHN-B31284 ).— Stn. CP 2830, 10°46.31’S 162°19.99’E, 264–314 m, 21 September 2007: 1 male (15.0 x 11.4 mm) ( ZRC 2008.0981 ).— Stn. DW 2804 ,

9°14.81’ S 161°20.96’ E, 150–175 m, 17 September 2007: 1 female (11.4 x 8.3 mm) ( MNHN-B31285 ). Philippines: PANGLAO 2004, stn. P2, 20 June 2004: 1 male (25.8 x 19.7 mm) (NMCR). – AURORA 2007, stn. CP 2656 , 16°02.8’ N 121°52.8’ E, 262–278 m, 20 May 2007: 1 male (14.1 x 11.3 mm), 1 female (18.6 x 13.7 mm) (NMCR). – Stn. CP 2667 , 15°55.64’N 121°46.6’E, 292–307 m, 21 May 2007: 1 female 11.6 x 8.3 mm ( ZRC 2008.0982 ).— Stn. CP 2708 , 15°07.1’N 121°37.9’E, 307–309 m, 28 May 2007: 1 male (15.6 x 11.3 mm) (NMCR).— Stn. CC 2743 , 16°01.3’N 121°51.1’E, 302–309 m, 2 June 2007: 1 female (25.8 x 19.5 mm) ( MNHN-B31286 ). Vanuatu: Espiritu Santo I., SANTO 2006, stn. AT 8 , 15°40.5’S 167°01.4’E, 366–389 m, 17 September 2006: 1 female (8.6 x 6.3 mm) ( MNHN-B31287 ).— Stn. AT 11 , 15°39.5’S 167°01.5’E, 272–286 m, 17 September 2006: 1 female (17.0 x 13.1 mm) ( ZRC 2008.0983 ). – Stn. AT 18 , 15°41.3’S 167°02.6’E, 321–336 m, 21 September 2006: 1 male (14.3 x 10.6 mm), 1 female (17.2 x 12.9 mm) (MNHN- B31288).— Stn. AT 19 , 15°33.94’S 167°00.5’E, 503–600 m, 21 September 2006: 1 badly damaged female ( MNHN-B31289 ).— Stn. AT 28 , 15°23.6’S 167°16.1’E, 342–350 m, 23 September 2006: 1 male (16.9 x 12.7 mm, photographed) ( ZRC 2008.0984 ). Taiwan: Kaohsiung County, Tongkuang fishing port: 1 ovigerous female (35.3 x 26.2 mm) ( ZRC 2000.2622 ). – Tungkang fishing port, 22 January 1996, 50 m: 1 ovigerous female (32.2 x

22.5 mm) (ZRC 2008.0698). – Tungkang fishing port, 5 January 1999: 3 males (17.3 x 12.3 mm, 20.4 x 15.3 mm, 27.6 x 19.5 mm), 1 ovigerous female (34.4 x 25.6 mm) (ZRC 1999.0714).

Remarks. Homolomannia sibogae was described from Indonesia ( Ihle 1912) and later reported from Japan ( Sakai 1935), Taiwan ( Tan et al. 2000) and the Philippines ( Guinot & Richer de Forges 1995; Takeda & Manuel 2007; Richer de Forges & Ng 2007). Some small specimens examined by Guinot and Richer de Forges (1995) from New Caledonia were tentatively referred to Homolomannia aff. sibogae . As discussed by Guinot and Richer de Forges (1995) with regards to specimens from New Caledonia, specimens from Vanuatu also differ from typical H. sibogae from the Philippines and Taiwan in the following aspects: all are relatively small (ca. 17.0 mm carapace length) but adults ( H. sibogae is a larger-size species, with specimens 40.7 mm in carapace length still immature); the carapace is more quadrangular with the branchial area relatively less inflated laterally; and the strong hepatic spine is directed anteriorly (directed more obliquely in H. sibogae ). While these differences suggest two separate species, we prefer to have a larger series of specimens from New Caledonia and Vanuatu to better understand the extent of the variation before a decision is made.

Interestingly, the bathymetric range of Homolomannia aff. sibogae from Vanuatu is from relatively shallower depths (173 to 600 m) than those known thus far for H. sibogae from elsewhere. Material from the Philippines has been recorded from depths of between 204–1258 m) ( Guinot & Richer de Forges 1995; Richer de Forges & Ng 2007). The single record of 50 m from southern Taiwan (ZRC 2008.0698) is an error as the collections from there were all from depths exceeding 200 m depth.