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Comparing three methods to estimate the average size at first maturity: A case study on a Curimatid exhibiting polyphasic growth
Author(s) -
Hashiguti Danielly Torres,
Soares Bruno Eleres,
Wilson Kyle Logan,
OliveiraRaiol Roberta Dannyelle,
Montag Luciano Fogaça de Assis
Publication year - 2019
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/eff.12451
Subject(s) - range (aeronautics) , logistic regression , maturity (psychological) , statistics , fish <actinopterygii> , biology , ecology , mathematics , fishery , psychology , developmental psychology , materials science , composite material
The average size at first |maturity (L 50 ) is among the most important parameters for fisheries management and conservation. This paper aims to compare three different methods for its estimation. Considering a classical approach, a logistic model was used (a) by determining the gonadal stage macroscopically; and (b) by using the GSI as proxy of sexual maturity; and finally; (c) by using the length–weight relationship ( LWR ) in a theoretical approach. The proposed methods were applied using data of a detritivorous fish, Cyphocharax abramoides , monthly sampled using gill nets. Captured individuals were measured, weighed, sexed and the gonadal stage was classified macroscopically and weighed. Estimated L 50 values using the macroscopic identification, GSI approach and LWR were not different from each other considering confidence intervals. Between the three different techniques, we concluded that the analysis of the LWR in fishes with polyphasic growth presented promising results as it only requires length and weight data to be performed and estimate a L 50 within the range of both classical logistic models analysed.