contribution à l'identification et à la détermination des caractères morphométriques de deux individus du genre lagocephalus , pêchés dans la région de Mostaganem ( Sidi Lakhdar )

Abstract

The goal of this work is the identification of two individuals of blowfish captured in the region of Sidi Lakhdar (Wilaya of Mostaganem) and determine the morphometric characteristics of the latter, by comparing them with other kinds of pufferslagocephalus existing in the Mediterranean region and in the Algerian coastal waters. The results showed that both specimens caught, match the native species of the Mediterranean L. lagocephalus lagocephalus. The identification and determination of morphometric characters showed that the two individuals of L. lagocephalus have respective overall lengths of 53,5cm for the individual captured in March and 49 cm for the individual captured in April. These two individuals are mature females with values of RGS and RHS respective 7.7; 6.37 for the individual caught in March and 74.5; 10.99 for the second individual caught in April. However, the individual captured in March appears older than caught in April because of existing dark spots on the underside, which is normally found only in juveniles and young adults. Also, the comparison results showed that for the same total length 53,5cm L. lagocephalus example has a higher weight 1,450 kg in Algerian coastal waters compared to that captured in Tunisian waters and is 1.436 Kg. This weight difference could beings due to trophic conditions that are more favorable to L. lagocephalus lagocephalus in Algerian coastal waters. After this work, and because of forecasts of population increases Lagocephalus gender, and other exotic species in the Mediterranean, linked to climate change, it must install an observatory where a regular inventory will be done with control the functioning of coastal ecosystems, to detect any changes or disruption.