Demersal fisheries Age Growth Growth curves Otoliths Otolith reading
Date de publication:
1985
Editeur:
INP (Ecuador)
Citation:
Boletín Científico y Técnico, 8(4). p. 51-62
Compte rendu:
342 specimens of sparid Calamus brachysomus ”Palma”, collected during a demersal trawl survey by the R. V. Tohallí in April and May1983, were examined. The different techniques used to prepare scales and otoliths for ageing are described and analysed. The otoliths were determined to be the most reliable for ageing studies; 87% of otoliths were readable. The rings observed were assumed to be annual. The mean lengths at age were used to determine the parameters of the Von Bertalanffy growth formula, giving: Lt=50.13(1-e-0.1473(t+2.0704)). The growth curve obtained must be considered provisional due to possible biases in the interpretation of the otoliths, and also due to those arising from the selectivity of the fishing gear.
