Weight-length relationships of seven fish species (Teleostei: Sparidae, Mullidae, Carangidae) of Western Mediterranean Sea (Oran Bay, Algeria)

No information currently exists on the weight-length relationships of Sparidae: Axillary seabream Pagellus acarne (Risso, 1827), bogue Boops boops (Linnaeus, 1758); Mullidae: Red mullet Mullus barbatus (Linnaeus, 1758), surmulet Mullus surmuletus (Linnaeus, 1758) and Carangidae: Atlantic horse mackerel Trachurus trachurus (Linnaeus,1758), Mediterranean horse mackerel Trachurus mediterraneus (Steindachner 1863), Blue jack mackerel Trachurus picturatus (Bowdich 1825), seven commercial fish species of Oran Bay in Western Mediterranean Sea. Data are presented for the first time for that region of the Mediterranean Sea to contribute and help comparative growth studies. Samples were collected from commercial catches at Oran Bay fisheries in Algeria. The values of the slope b in the lengthweight relationship, W=aLb ranged from 2.841 to 3.296. The coefficients of correlation r2 were comprised between 0.85 and 0.97. “a” and “b” parameters were compared with other fishing sites for the same fish species with Froese plot [Log a=ƒ(b)]

Reproductive biology of Pagellus acarne (Risso, 1927) (Teleostei: Sparidae) off western Algerian waters (Western Mediterranean)

The reproduction of Pagellus acarne caught in Oran Bay was studied. The samples used were sorted monthly from commercial catches of coastal trawlers operating in this area from April 2008 to July 2009. The overall sex ratio was in favor of females 1:1.27 and length frequency distribution according to sex revealed that the females were highly representative beyond 20.5 cm of total length presuming a sexual inversion already described for this sparidae. The estimated lengths at maturity (Lm) were 12.8 cm for females and 16.0 cm for males. Two spawning periods were made out by the follow-up of the gonado and hepato somatic indexes: a spring period from April to June with a peak in May and an autumnal period, between November and January with a peak in December. The closed season in Oran Bay extends from 1st May to 31th August, which is to our opinion insufficient to safeguard the renewal of the resource and its spawning stock

Study of reproductive aspects of <em>Trachurus trachurus</em> (Linnaeus, 1758) from western coast of Algeria

2469-2476In the present work, the reproductive study of the fish species Trachurus trachurus (Linnaeus, 1758) in Algeria, was investigated which is important for fishery resources and conservation management. 1495 samples were collected from Oran Bay (Western coast of Algeria) between July 2010 and June 2011. This paper provides values of sizes at first sexual maturity (L50) that were estimated for males at 18.42 cm and females 18.28 cm, respectively. The spawning period for the population extends from January to May and the spawning peak occurs from January to March. However, the factor of condition (K) increased in summer during the sexual resting phase. This factor is weak in winter during the period of reproduction. Regarding the sex ratio, there was no significant difference in the number of males and females