Review of identity and biology of species of the family Macrouridae, from the CCAMLR fishery in the Ross Sea, Antarctica

Samples of macrourid rattail bycatch from the toothfish fishery in sub-areas 88.1 & 88.2 in 2002 were identified by observers and returned to New Zealand for subsequent confirmation of their identity by NIWA researchers. Two species were found, Macrourus whitsoni and M. holotrachys. A previously aged sample from 1999 was confirmed as being M. whitsoni based on otolith comparisons and the geographic source of the aged sample. This confirms the preliminary age estimates from the ageing study. Regression equations relating total length to snout-vent length, total length to weight, and snout-vent length to weight were generated. For all regressions there were significant differences between the sexes and between the data origins (NIWA and observer). Observer data were derived from fresh specimens and NIWA data were derived from frozen-and-thawed specimens. The age and length at maturity for M. whitsoni males is 12 years and 46 cm TL, for females it was 14 years and 50 cm TL.