Stylet increment analysis in Eledone cirrhosa from the Northwestern Iberian population

No abstracts are to be cited without prior reference to the author.

Specimens of Eledone cirrhosa (Lamarck, 1798) were obtained from trawling fishing undertaken from March 2009 to March 2010 in north-‐‑western Iberian coasts. Stylet Increment Analysis (SIA) was applied to 122 specimens ranging 67-‐‑950 g, representing the size classes detected by modal progression analysis performed to the catches collected throughout the year. Despite the significant correlation between size and age, modal progression analysis does not seem to provide an adequate vision of age-‐‑structure in this area. Assuming a daily deposition rate of growth increments in the stylet, the age of the specimens was estimated and compared with morphometric data of the animals and the stylets to determine the best morphometric predictor of age. Results showed differential longevity between sexes, with females reaching a life span of up to two years. Based on estimated age, hatching date was back-‐‑calculated, showing a spawning peak during winter. The recruitment of E. cirrhosa in Galicia waters would occur when animals reach 3-‐‑4 months old. Based on size at first maturity estimated for this species in this area and DML-‐‑Age relationships, females would achieve maturity at around one year old, while males would do it at approximately at 8-‐‑9 months old. The results obtained were discussed according to the scarce information available from the Iberian population.