Premium
Age, growth and reproduction of the white seabream D iplodus sargus sargus ( L inneaus, 1758) off the eastern coast of A lgeria
Author(s) -
Benchalel W.,
Kara M. H.
Publication year - 2013
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.2012.02057.x
Subject(s) - diplodus , biology , sparidae , hermaphrodite , population , reproduction , sex ratio , zoology , quadrat , fishery , ecology , mediterranean climate , fish <actinopterygii> , demography , shrub , sociology
Summary The objective of this study was to determine the basic population‐specific parameters necessary for fish stock assessment in the area and to compare these with data from other M editerranean regions. White seabream D iplodus sargus sargus (n = 449) were caught along the A lgerian coast between D ecember 2005 and D ecember 2006. Total length ranged from 12.2 to 34.6 cm, representing age classes between 0 and 10 years. Validity of the otolith readings for estimating age and growth was supported using the back‐calculation method. The von B ertalanffy growth parameters for all fish were calculated as: TL = 36.3 cm, k = 0.154 year −1 , t 0 = −0.488 year. The growth performance index (φ) showed a relatively slow growth of the local population. The length‐weight relationship showed an isometric growth ( b = 2.98; r = 0.98). Subspecies D iplodus sargus sargus was characterized as being a proterandric hermaphrodite. Overall ratio of males to females was 1 : 1.4, with males predominant in the smaller size intervals and females in the larger ones. The reproductive season extended from J anuary to M ay, with a M arch– A pril peak in spawning activity. Fifty per cent maturity of the tested cohort was reached at a total length of 20.2 cm for males and 20.0 cm for females.