Fecundity of the Norway lobster Nephrops norvegicus in Galicla (NW Spain) and a review of geographical patterns

The fecundity of the Norway lobster Nephrops norvegicus in Galician waters (NW Spain) was estimated based on the number of eggs attached to the pleopo ds of ovigerous females in the initial, middle and final stages of the incu bation period. The number of eggs per brood was related allometrically to t he carapace length (CL), with an allometry coefficient ranging between 3.0 and 4.1 in the different incubation stages (P > 0.05). Incubation lasts 6-7 months (from August-September to January-February) and the average egg los s is estimated to be 44% during this period. The mean fecundity (correspond ing to a mean CL of 38.6 mm) was 2636 eggs in the initial stage and 1475 in the middle and final stages of incubation. The literature points to a high variability in the fecundity of the Norway lobster throughout its geograph ical range of distribution. Fecundity decreases with latitude in the NE Atl antic from Western Ireland to the South of Portugal, with the Mediterranean populations showing lower values than those in the Atlantic. However, cons idering the periodicity of spawning, which tends to be biennial towards the northern distribution area, the annual production of eggs per female may b e similar in the different zones and may even increase towards the south. E gg loss during the incubation period has been estimated at between 32 and 6 8% for the different geographical areas.