engleski

Biological parameters of the saddlead bream, Oblada melanura in the eastern Adriatic

Age, grovth, sex ratio, and mortality were analysed for saddlead bream collected in the eastern Adriatic from June to August in 1993 and 1994. The slope (b values) of the total length-weight regression, which differ significantly between sexes, indicate positive allometric growth for females (b = 3.123) and isometric growth for males (b =3.017) (N = 5341). Fish aged 1-11 years were present in the samples (N =1729). Growth in length for both sexes was expressed using the Bertalanffy equation, Lt = 34.13 (1-exp(-0.208(t+0.750))). Females grow slower (K = 0.201) than males (K = 0.233). The overall ratio was 1:1.20 in favour of females. Males were dominant in length classes 11.0-20.0 cm, females in length classes 21.0-33.0 cm. All individuals larger than 29.3 cm were female. Total and natural mortality were Z =1.08 years-1 and M = 0.47 years-1. The exploitation rate, E = 0.56, revealed high fishing pressure on the stock in the studied area

Oblada melanura; age; growth; sex ratio; mortality; Eastern Adriatic

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