Rochinia ahyongi McLay, 2009

Lee, Bee Yan, Forges, Bertrand Richer De & Ng, Peter K. L., 2019, Deep-sea spider crabs of the family Epialtidae MacLeay, 1838, from Papua New Guinea, with a redefinition of Tunepugettia Ng, Komai & Sato, 2017, and descriptions of two new genera (Crustacea: Decapoda: Brachyura: Majoidea), Zootaxa 4619 (1), pp. 1-44 : 13

Rochinia ahyongi McLay, 2009

( Fig. 6A )

? Sphenocarcinus— Clark & O’Shea 2001: 15.

Rochinia ahyongi McLay, 2009: 30 , 33, figs. 12, 13 (type locality: Rumble V Seamounts, Kermadec Ridge, New Zealand). Rochinia ahyongi— Richer de Forges & Ng 2013: 468 (list).

Material examined. Papua New Guinea: 1 male (11.0 × 7.8 mm), 1 ovigerous female (11.0 × 7.9 mm) , 1 female (7.7 × 5.3 mm) ( ZRC 2018.1480 , ex. MNHN-IU-2014-9855), stn DW4300, Solomon Sea , Siga Island, 10°45’S 151°06’E, 470–526 m, coll. MADEEP Expedition, 2 May 2014 .—2 ovigerous female (11.6 × 8.4 mm, 11.0 × 7.8 mm), 1 female (10.8 × 7.7 mm) (MNHN-IU-2014-18328), stn CP4306, Solomon Sea , Siga Island, 10°46’ S 151°10’ E, 666–680 m, coll. MADEEP Expedition, 2 May 2014 .— 1 ovigerous female (12.3 × 9.0 mm) ( ZRC 2018.1481 , ex. MNHN-IU- 2015-83) [photographed], stn DW4300, Solomon Sea, Siga Island , 10°45’S 151°06’E, coll. MADEEP Expedition, 2 May 2014 .— 1 male with bopyrid (9.9 × 7.2 mm) (MNHN-IU-2015-376), stn CP4306, Solomon Sea , Siga Island, 10°46’S 151°10’E, 666–680 m, coll. MADEEP Expedition, 2 May 2014 .— 1 ovigerous female (13.3 × 9.2 mm) (MNHN-IU- 2015-82) [photographed], stn DW4305, 10°45’S 151°10’E, 666–680 m, coll. MADEEP Expedition , 2 May 2014 .

Remarks. Rochinia ahyongi McLay, 2009 , was described from New Zealand from a depth of 772– 951 m. The specimens from Papua New Guinea, however, were collected in shallower water, from 470– 680 m. The PNG specimens are generally larger than the type specimen, and differ from the type in having three granules on the gastric region, and the two granules on each epibranchial region ( Fig. 6A ) (versus the lack of distinct granules on the type material; cf. McLay 2009: figs. 12a, 13a). From the figures by McLay (2009: fig, 12), the type specimen is probably a juvenile male and as such, the differences observed here are probably associated with size. The specimens on hand agree with the type in all other aspects. The PNG material has a typical “ Rochinia type ” of G1 that is slightly flattened at the tip to form only one point. McLay (2009) mentioned that the specimen has a bilobed G1 tip, which is seen in Rochinia brevirostris ( Doflein, 1904) (cf. Griffin & Tranter 1986: fig. 62c, d). Based on his figure ( McLay 2009: fig. 13d), however, the bilobed tip is not at all obvious, as is the case for the present material. For these reasons, we believe our material is conspecific with R. ahyongi .

The species is recorded for the first time from PNG.

Figures

FIGURE 6. Color in life. A, Rochinia ahyongi McLay, 2009, ovigerous female (12.3 × 9.0 mm) (MNHN-IU-2015-83), Papua New Guinea; B, R. boucheti Richer de Forges & Ng, 2013, male (19.5 × 14.1 mm) (MNHN-IU-2014-8130), Papua New Guinea; C, R. fultoni (Grant, 1905), ovigerous female (18.6 × 11.8 mm) (MNHN-IU-2013-2343), Papua New Guinea; D, R. despereaux n. sp., ovigerous female (16.0 × 10.4 mm) (MNHN-IU-2013-2277); E, R. despereaux n. sp., holotype, male (15.2 × 10.1 mm) (MNHN-IU-2011-3878), Papua New Guinea.