Growth Per Moult of Tagged Lobsters (Homarus americanus) in Bonavista Bay, Newfoundland

The suitability of the sphyrion tag for lobster growth studies is demonstrated by comparing growth of ferromagnetic- and sphyrion-tagged lobsters. Carapace length and total weight increments in one moult of 54 males (52–92-mm carapace length) tagged with sphyrion tags averaged 11.4 mm (15.7%) and 185.9 g (60.8%). For 56 females 57–89-mm carapace length they averaged 9.8 mm (13.3%) and 136.3 g (42.5%). Differences in growth per moult between sexes increased with size. For both sexes percent carapace length increment decreased with increase in carapace length but more rapidly for females. Carapace length increment increased with increasing carapace length for males, but for females there was no significant change over the size range considered. Incidence of moulting for sphyrion-tagged lobsters was 83.1% and comparable with an observed estimate (85.2%) from field samples obtained shortly after the moulting season.