Natural Growth and Mortality of the Golden Grey Mullet Liza Aurata (Risso, 1810) In the Lagoon of Klisova-Messolonghi (W. Greece)

George N Hotos

doi:10.32861/ajls.54.23.31

Abstract

Growth and mortality of L. aurata (Risso,1810) were estimated in the lagoon of Klisova-Messolonghi (W. Greece), based on age estimation from scale readings of a total of 1048 individuals, ranging between 10 and 59 cm in total length (TL). Age determination revealed nine age classes (0+ to 8+). Maximum age was found to be 8 years for females and 6 years for males respectively. The growth pattern of L. aurata exhibited allometry (b=3.26). The species seems to achieve 34% of its growth during the first year; thereafter the annual growth rate drops. Both sexes presented similar von Bertalanffy growth curves. The von Bertalanffy growth function for the estimated total length-at-age was found Lt = 70.78 [1 - e -0.129(t+1.345)] for the combined sexes. Otolith weight, length and width were tested and they were found to be very good predictors for age. Between the present L. aurata growth parameters and those of other Mediterranean, Caspian and Atlantic Sea for the same species, there were found significant differences in its growth parameters. The total (Z) and natural (M) mortality rate was found to be 0.54 years-1 and 0.33 years-1 respectively. The estimated exploitation rate was found to be E=0.395 which suggests that the existing fishing pressure on L. aurata is rather moderate in the investigated region.

Highlights

Golden grey mullet, Liza aurata (Risso, 1810), locally named “mixinari”, is a mugilid fish of commercial value for fisheries, especially in internal waters
The aim of the present study is to provide data on the growth biology and exploitation parameters of L. aurata, and the results may serve as a guideline for the management of this and possibly the other species of Mugilidae of Messolonghi lagoon
The Kolmogorov-Smirnov statistic was used to test for significant differences between the groups of observed (MTLC) and back-calculated lengths of all ages

Summary

Introduction

Liza aurata (Risso, 1810), locally named “mixinari”, is a mugilid fish of commercial value for fisheries, especially in internal waters. The production of L. aurata accounts for almost 15% of the total annual production of mugilids in the Messolonghi lagoon complex, while the mugilid production is almost half of the total fishing production in this area [1]. For the rest of Europe Andaloro [5] presented data on age and growth of its population in the Marsala lagoon (Sicily), Arruda, et al [6] on age and growth in Ria de Aveiro (Portugal) and Kraljević and Dulčić [7] investigated its age, growth and mortality in the N. This species is of interest for aquaculture [8]

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