Lenght-weight relationship and condition factor of the axillary seabream (Pagellus acarne) in coastal waters of Lybia

Abstract

Axillary seabream Pagellus acarne is an important commercial species, fished along the eastern Atlantic coasts and the Mediterranean Sea. It is a protandric hermaphrodite (most individuals are first males, becoming females at sizes of about 17 to 29 cm, at age of two to seven years). Length-weight relationship and condition factor were analyzed on a sample of 100 specimens from a commercial catch. Fish were caught with trammel nets in September 2015, in coastal waters of western Libya offshore Sabratha. For each individual, the total body length (TL) in mm, body weight (W) in g, and sex were determined. Total body length of the sampled fish ranged from 150 mm to 215 mm, and all individuals were arranged into six 10-mm length classes. More than 80% of individuals were larger than 160 mm. The highest percentage of individuals were in the 160-169 mm length class (33%). Weight range of analyzed specimens ranged from 40 to 125 g. The length-weight regression parameters were: a = 0.00004, b = 2.76, r² = 0.80, which indicates a negative allometric growth. The mean value of the Fulton’s condition factor was similar for males (1.32) and females (1.36). However, it was observed that females of the same length have better condition than males.