Metadynomene tanensis ( Yokoya, 1933 )

Published, First, 2009, New records of crabs (Decapoda: Brachyura) from the New Zealand region, including a new species of Rochinia A. Milne-Edwards, 1875 (Majidae), and a revision of the genus Dromia Weber, 1795 (Dromiidae), Zootaxa 2111, pp. 1-66 : 11-12

Metadynomene tanensis ( Yokoya, 1933)

( Fig. 2a, b)

Dynomene tanensis Yokoya, 1933: 96 , fig. 38.

Dynomene praedator — Sakai 1976: 30, fig. 17. – Naga & Tsuchida 1995: 108, pl. 1, fig. 2. Not Dynomene praedator A. Milne-Edwards, 1879 .

Metadynomene tanensis — McLay 1999: 521, figs 4d, 6c, 7f, 9d, e, 11, 13c, e, f, 14e, 25b, 27, 28. — McLay et al. 2001: 964. — Ng et al. 2001: 6. — Guinot & Quenette 2005: 284, fig. 4A, B. — McLay & Ng 2005: 24.

Material Examined. East Cape: 1 ovigerous female, 19.2 mm x 18.0 mm, 37°30’S, 179°00E, 307–340 m, Taranui, F 867, TAM, 2 Oct. 1968. ( NIWA 48580 )

Remarks. The discovery of M. tanensis is the first record of the Dynomenidae in New Zealand. Dynomene pilumnoides is also being reported from New Zealand for the first time (see below). The systematics of this family has been reviewed by McLay (1999). The specimen was discovered in the NIWA collection, where it had been in storage for more than 30 years. The type species of Metadynomene McLay, 1999 is Dynomene tanensis Yokoya, 1933 , collected off the eastern coast of Japan. The geographical distribution of this species includes Taiwan, Indonesia, New Caledonia, Loyalty Is, Chesterfield Is and Vanuatu, to which we can now add New Zealand. A large male specimen reported as “ M. tanensis ” by McLay (1999: 522) from the Tuamotu Archipelago, French Polynesia, probably belongs to an undescribed species. There are two other species: M. crosnieri McLay, 1999 , from the Glorieuse Is, Indian Ocean and M. devaneyi ( Takeda, 1977) from the Hawaiian Is and the Marquesas Is, French Polynesia. Species of this genus inhabit for the most part water between 200 and 500 m and some are associated with precious corals ( Corallium sp. ). They seem to live on rocky bottoms. Coarse sand, broken shell, rocks, Glycymeris , Venericardia , Pecten (Bivalvia) , Munida (Anomura) , pagurids, electric ray, octopus and ophiuroids were also collected along with the New Zealand specimen of M. tanensis .

There is a superficial resemblance between this species and Metadromia wilsoni nov. comb. because both species have a dense, short, uneven tomentum covering the carapace, but they are easily distinguished because M. tanensis only has the last pair of legs (P5) reduced, whereas M. wilsoni has the last two pairs (P4 and P5) reduced, although not as much as for M. tanensis P5.

Distribution Metadynomene tanensis is known from Taiwan, Indonesia, New Caledonia, Loyalty Is, Chesterfield Is and Vanuatu, and now from East Cape, New Zealand. Depth range is 205– 520m.