Resumen del producto

In Costa Rica, the main catches and landing of dolphinfish are made in the Costa Rican Pacific Ocean by sportfishing and commercial fishing fleets. Commercial fishing fleets can be small, medium or large scale depending on their autonomy. The fishing gear is longline, which is modified in terms of size and type of hook during the dolphinfish fishing season. Although dolphinfish is caught throughout the year, the highest catches are recorded from October to January. Despite the social and economic importance of this resource, little is known about its basic biology. Therefore, this study shows preliminary results of age and individual growth from a sampling of 363 organisms (215 females and 148 males) caught by medium and large-scale commercial fleet during January 2017 and January 2018. The fork length range for males and females was 72-134 cm and 77-122 cm, respectively. Saggittal otoliths were placed in a mold with crystal resin. The crystal block was then carefully positioned in a low speed diamond wafering saw and aligned to obtain a section containing both the primordium and the post-rostral tip. Sections were mounted on slides using a thermoplastic and polished to a thickness of approximately 5-15 µ. Daily increments were counted on those otolith sections by two independent readers and without previous knowledge of length and weight of the analyzed organisms. The von Bertalanffy model for mixed sexes obtained L8 = 131.12, k = 1.66 y t0 = -0.01. Further studies should imply processing all otoliths and applying multi-model inference for individual growth parameter estimation. This study contributes to future stock assessments of the dolphinfish population of the Eastern Pacific Ocean.

Palabras clave: age; Growth; Dolphinfish; von Bertalanffy model

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