Some Biometric Observations on Nephrops norvegicus (L.)

Abstract

Current size legislation on Norway lobsters is based on overall length, while for scientific purposes the more accurate carapace length is used. The relationships between these measurements, derived from samples of males and females taken in the Moray Firth and the Minch, are obtained. No sex difference is detected, but the overall length (L) at a given carapace length (C) is found to be slightly higher in the Minch than in the Moray Firth. The best fitting relationships for the two areas are found to be Moray Firth: L = 3·004C + 9·2 Minch: L = 3·004C + 10·1 These relationships are compared with ones available for English, Irish, Portuguese and Faeroese stocks and, with the exception of the latter, they are found to be very similar everywhere.

Other relationships obtained from the Scottish data are derived. These include the relationship between carapace length and tail width, body weight and tail weight and total weight and carapace length. Sex and area differences in these relationships are studied.