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Email the author (Login required) Age estimation and individual growth of dwarf hake Merluccius productus along the southernmost limit of the Baja California Peninsula
Submited: 2023-11-24 14:17:12 | Published: 2024-10-30 20:32:52
DOI: https://doi.org/10.3856/vol52-issue5-fulltext-3190
Abstract
The Pacific hake Merluccius productus is a commercially important species on the west coast of North America. A non-exploited population south of the Baja California Peninsula known as dwarf hake, from which little is known, has been described. The present study analyzed the age and growth of the dwarf hake off the west coast of Baja California Sur, Mexico. A subsample of 240 otoliths and standard length (SL) data from 932 specimens captured from May to December 2015 was used. The annual formation of increments in otoliths was verified by marginal increment ratio and edge analysis. Age was estimated from transversal sectioned otolith annuli counts, and SL growth was analyzed using a multimodel inference approach. The von Bertalanffy growth model (VBGM), generalized VBGM, Gompertz, logistic, and Johnson growth models were fitted to observed and back-calculated length-at-age data sets grouped by sex. SL records ranged from 11.5 to 27.5 cm, where females reached a larger size and older ages than males. The age structure was well represented for the first six years, with a mode at three years age class and maximum longevity registered in a female of 10 years. According to Akaike's information criterion, the generalized VBGM was most appropriate for females (L∞ = 31.36 cm, k = 0.15), while VBGM provided the best fit for males (L∞ = 25.35 cm, k = 0.28 cm yr-1). The parameter values suggest that the dwarf hake is a fast-growing, small-size fish. These results provide the first estimated growth parameters for the dwarf hake off the southernmost limit of the Baja California Peninsula.
