Main: NECTOCARCINUS ANTARCTICUS AND . . .

New Zealand Journal of Marine and Freshwater Research abstracts

NECTOCARCINUS ANTARCTICUS AND N. BENNETT1 (BRACHYURA: PORTUNIDAE) IN THE NEW ZEALAND REGION

W. de L. Main

New Zealand Oceanographic Institute, Department of Scientific and Industrial Research, Wellington, New Zealand

Abstract The distributions of two swimming crabs endemic to the New Zealand region are described, mostly from material obtained at 118 of 2544 New Zealand Oceanographic Institute benthic stations sampled. Nectocarcinus antarcticus (Jacquinot) was found within the geographic limits 34°S-51°S and 166° E-176° W, with concentrations around Cook Strait, the Chatham Rise, Foveaux Strait, and the Auckland Is. N. bennetti (Takeda & Miyake) occurred between 44° S and 53° S, and 165° E and 180°, most frequently in the south and west, on the 'highs' of the Campbell Plateau. Although the distributions overlap between 44° S and 51° S, and this overlap zone produced most of the available material, only one joint occurrence of the two species was noted. This apparent separation was not satisfactorily explained by any of the ecological factors recorded. The depth ranges of both species were broadly similar (0-550 m for TV. antarcticus, 20-474 m for JV. bennetti) ; both were most frequently obtained at depths less than 200 m. Both occurred primarily on the coarser sediment grades, though N. antarcticus occupied a broader range of grades than N, bennetti. The size ranges of the two species were similar; carapace lengths were 8.0-62.0 mm for N. antarcticus and 5.8-68.0 mm for N. bennetti. The larger specimens of both species were found towards the southern limits of distribution. Larger specimens of N. antarcticus were absent from depths greater than 120 m; smaller N. antarcticus and all N. bennetti occurred throughout their respective depth ranges. Ovigerous N. antarcticus (smallest, 8.8 mm carapace length) were obtained at depths of 17-263 m from May to October; ovigerous N. bennetti (smallest 36.1 mm) were from depths of 150-183 m in May only.

N.Z. Journal of Marine and Freshwater Research 8 (1): 15-38
(Received for publication 10 March 1972; final revision received 23 August 1973)

PDF file of entire paper: medium quality (2180K); (scanned from paper original: notes about this process)

This year's abstracts | Journal home page | All abstracts | Publishing home page