Maturity, fecundity and reproductive potential of the European lobster ( Homarus gammarus) in Ireland

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Tully, O., Roantree, V., Robinson, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2001
• Subjects: European lobster; Homarus gammarus
• Online Access: http://dx.doi.org/10.1017/s002531540100340x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002531540100340X

Fecundity and size at maturity of the European lobster Homarus gammarus (Crustacea: Decapoda) was estimated in four coastal regions of Ireland. Egg size increased with carapace length (CL) (egg size=0·9939×ln (CL)−3·0809). The size–fecundity relationship for all coasts combined was (fecundity=0·0044×CL 3·1554 ). Physiological maturity was assessed using ovary colour, ovary factor, ova size, abdomen width/CL ratio, cement gland activity and moult status as criteria. Size at 50% maturity varied from 92·5 to 96 mm depending on region. The size–maturity relationship for all coasts combined was (Maturity= 1/(1+exp(14·595−0·15598×CL))). Over 60% of lobsters in the commercial landings were under the size at 50% maturity. Relative reproductive potential (RRP) of different size-classes was calculated from the size–fecundity and size–maturity models and the numbers by length in the landings. The modal RRP size-class was 98–100 mm. The commercial landings were dominated by the 86–92 mm size-classes.