Trichopeltarion janetae Ahyong, 2008

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 : 34-36

Trichopeltarion janetae Ahyong, 2008

Fig. 15

Trichopeltarion janetae Ahyong, 2008: 17 , figs 7–11, 28 D) Material Examined. Chatham Rise (Graveyard Complex): 2 females, 13.9 mm x 12.3 mm, 16.1 mm x 14.9 mm, 42°43.03’S, 179°57.55’W, 1051– 964 m, Tangaroa , stn TAN0104/82, 17 Apr. 2001 ( NIWA 48583 ); 5 females, 12.5 mm x 11.3 mm, 14.1 mm x 12.7 mm, 18.9 mm x 16.9 mm, 20.2 mm x 17.0 mm, 23.7 mm x 21.0 mm, 1 ovigerous female, 20.5 mm x 18.2 mm, 1 male, 15.9 mm x 13.8 mm, 42°43.10’ S, 180°5.43’E, 1075– 1008 m, Tangaroa , stn TAN0104/333, 20 Apr. 2001 ( NIWA 48582 ).

Colville Ridge: 1 female, 11.6 mm x 11.0 mm, 32°36.88’S, 179°38.17’W, 888– 741 m, Tangaroa , stn TAN0205/34, 17 Apr. 2002 ( NIWA 48728 ) .

Remarks. This species was described using a large sample of the new species from eastern New Zealand, from Bay of Plenty south to the Chatham Rise and Bollons Seamount at depths of 830–1506 m. The species has also been reported from seamounts off Tasmania ( Ahyong, 2008) so the female from the Colville Ridge bridges the gap between NZ and Australia. An ovigerous T. janetae female, 20.5 mm x 18.2 mm, carried around 1600 eggs of diameter 0.95 mm. The smallest ovigerous female reported by Ahyong (2008) was 16.7 mm x 17.3 mm. This species has a relatively small abdomen that is totally inadequate for protecting the brood of eggs (cf. the high level of protection provided by the brood chamber in Pyromaia tuberculata , Pseudopalicus undulatus and Tanaoa pustulosus see herein). Thompson & McLay (2005) suggested that in Trichopeltarion , and some other atelecyclid genera, brood protection of the relatively small number of large eggs may be provided by living in a burrow.

T. janetae is readily distinguished from the only other species in New Zealand waters, T. fantasticum Richardson & Dell, 1964 because it is much smaller, the carapace is densely setose rather than sparsely setose and the last anterolateral tooth is small compared to the large tooth in T. fantasticum . Males differ in that T. janetae do not have the enormously developed right cheliped; sexual dimorphism is much more modest. Ahyong (2008) provides excellent photos of the two NZ species of Trichopeltarion .

Distribution The distribution of Trichopeltarion janetae includes Tasmania, Colville Ridge and New Zealand. Depth range is 830–1700 m.