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Age and growth determination in a marine catfish using an otolith check technique
Author(s) -
WarBurton K.
Publication year - 1978
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1978.tb03451.x
Subject(s) - otolith , catfish , biology , fish <actinopterygii> , fishery , fish measurement , population , growth curve (statistics) , zoology , mathematics , statistics , demography , sociology
A direct and accurate method of age determination using the relative positions of otolith growth checks is described. In the catfish Guleichthys cuerulescens , otolith length and depth were both linearly related to fish length. Checks appeared to be formed twice per year, at the beginning and at the end of the rainy season (late June to late September). Growth was more rapid in the wet season, when water temperatures were at their height. Calculated mean fork lengths of spring‐spawned fish after the first four years of life were respectively 11.5, 19.3, 26.3 and 33.1 cm. Few individuals grew beyond 40 cm, the survival of most of the population being five years or less, but a maximum recorded length of 51.5 cm suggested that catfish may occasionally persist into their seventh or eighth year. The shape of the growth curve indicated that, since a permanent seaward migration of older fish is unlikely, then natural mortality among lagoon‐resident G. cuerulescens occurs before a growth asymptote is reached.