Résumé:
Auxis rochei, teleost is part of the family Scombridae has an economic interest seen its
popular commercial value especially in western Algeria.
Frigate tuna (Auxis rochei Risso 1810) is an oceanic species found in equatorial areas of the
major oceans, it is a highly migratory species with a strong tendency to form schools.
The biological study aims to address the biological characteristics of the species targeted by
tuna fishing. The choice is based on the criterion of the quantitative and qualitative
importance of the landings.
The study is based on a set of 110 individuals, 65 were females and 45 males; sampled Bay
Mostaganem for 4 months, between October 2015 and January 2016.
The sex ratio shows the dominance of females (59.09%). Spinal average is 38.41.
The calculated relationships highlight an upper bound allometry between total length and fork
length and between height and weight at Auxis rochei captured in the Bay of Mostaganem.
This expresses that the total length is growing faster than the fork length and total weight (Wt)
is growing faster than the total length (Lt).
Von Bertalanffy growth parameters were determined by studying the size and using the
structures FISAT II software (version 1.2.0) software recommended by FAO. Asymptotic
length (L ∞) of Auxis rochei is 47.78 cm; the growth coefficient (K), which determines the
speed of the fish to approach the asymptotic length, is high, it is 0.48.
