IJRRAS 19 (3) ● June 2014 www.arpapress.com/Volumes/Vol19Issue3/IJRRAS_19_3_03.pdf 199 SOME ASPECTS ON THE REPRODUCTIVE BIOLOGY OF GREATER FORKBEARD PHYCIS BLENNOIDES (BRÜNNICH, 1768) IN WESTERN ALGERIAN COASTS (OSTEICHTHYES, GADIDAE) Sofiane Med el Amine Benghali 1,2, *, Salim Mouffok 2 , Ali Kherraz 1,2 & Zitouni Boutiba 2 1 Department of Marine Science and Aquaculture, FSNV-UMAB-Mostaganem, Algeria 2 Environmental Surveillance Laboratory, Department of Biology, Faculty of natural sciences and life, University Oran, Algeria BP 1524 El Menaouar. *Corresponding author, email: sbenghali@yahoo.com ABSTRACT The aim of this work was to study the annual reproductive cycle of Great forkbeard (Phycis blennoides, Brünnich, 1768) through analysis and description of some physiological index. A sample of 225 females was captured between January 2012 and December 2012 from the Western coast of Algeria, from Mostaganem. Fish length and weight varied between 17.60-37.80 cm and 38.33-403.03 g, respectively. Condition factors (K), gonadosomatic index (G.S.I.) and hepatosomatic index (H.S.I.) were calculated monthly. Sex ratio of males to females was 1:0.91. The estimated length where 50% of analyzed individuals were sexually mature was 24.73 cm for females. The peak value of gonad somatic index was recorded in September and continued throughout the October, indicating the highest spawning activity when the Kn values are low. Keywords: Gonadosomatic Index, Hepatosomatic Index, First Maturity, Spawning Period. 1. INTRODUCTION The greater forkbeard, Phycis blennoides (Brünnich, 1768) is a common gadoid occurring in the Mediterranean and in the North-eastern Atlantic, from Iceland to Morocco (Tortonese, 1975; Fisher et al., 1987; Davis & Edwards, 1988; Whitehead et al., 1989). It is usually found on muddy or sand bottoms in depths of 100-650 m, the total length at first sexual maturity for males and females are 18-20 cm and 22-23 cm respectively (Gallardo-Cabello & Gual-Frau, 1984). In the Mediterranean, P. blennoides spawns from June to August (Gallardo-Cabello & Gual-Frau, 1984). Taking into account that length at maturity, fecundity and sex-ratio are some of the most important parameters in studying reproductive dynamics of gadoids population, this study was carried out by examination of annual changes of the gonado-somatic index (GSI), hepato-somatic index (HSI) and condition factor (Kn) in order to evaluate the level of the exploitation in the Algerian coasts. In fact, on southern Mediterranean coast, the knowledge on P. blennoides is still fragmentary, being limited to some remarks about Algerian waters. Therefore, the aim of the present paper was to study the reproduction and condition of this species. This is the first paper with a complete analysis of the biology of P. blennoides in south-western Mediterranean. 2. MATERIAL AND METHODS Reproduction study A series of biological samples was conducted on specimens of P. Blennoides caught by the commercial trawlers in the sampling area of Mostaganem (Fig.1). Specimens’ total length was measured and both sex and maturity were reported for females which represent the focus of our study, four different stages were defined (Table 1) according to (ICES, 2007).