Weight-length relationships are presented for 60 fish species captured from Izmir Bay, Central Aegean Sea. Samples were collected using bottom trawls (mesh sizes 24 mm at stretched cod-end). The b values W ¼ aL b showed a mean value of 3.027 (SE ¼ ±0.03) and more than 50% of the values ranged between 2.912 and 3.189. One species, Cepola macrophthalma, showed strong negative allometric growth.

SummaryThis work focuses on reproductive biology aspects of Uranoscopus scaber from the coast of the Aegean Sea. In total, 175 U. scaber specimens were collected in Izmir Bay using trawl nets from January to December 2005. The reproduction period according to gonadosomatic index (GSI) values extents from March to September, with a peak in May (6.32 ± 1.2). Oocyte diameters taken from 59 mature gonads ranged from 62 to 1860 lm. Maximum batch fecundity (BF) was 58091 (mean: 11556 ± 1445) in large oocytes in May, and 8408 (mean: 2821 ± 945) in hydrated oocytes in September. The BF increased with total length and body weight, excluding the ovaries. Total length (TL)-BF relationships and fish weight-BF relationships were BF = 0.0034TL 4.6248 (r = 0.47) and BF = 59.166W)3101 (r = 0.49), respectively, according to the oocyte size frequency method. There was a linear relationship between BF and fish size.

In this study, cod end mesh selectivity of braided polyethylene for the deep-water rose shrimp, Parapenaeus longirostris was investigated in the Aegean Sea. Fishing trials were carried out on the commercial trawler, "Hapuloglu" between 9 and 12 December 2006. Data were collected by a diamond mesh cod end of the 1200 mesh trawl net commercially used. The mean mesh size of the cod end meshes (nominal 46 mm) was measured near to 50 mm by using a calliper rule. Selectivity data were collected by the covered cod end method and analysed by means of a logistic equation with the Maximum Likelihood method. The mean selectivity curves were estimated from the individual hauls that were fitted taking into account the variation between hauls. The 50% retention length and the selection range of combined (male + female) P. longirostris were estimated as 19.6 mm (carapace length) and 6.2 mm, respectively, and there was no significant difference between the L 50 values of the male and female sexes (p < 0.05). Consequently, the cod end showed relatively better selectivity considering the size at 50% sexual maturity of the species, and the effect of increased mesh size and of the material used are of great importance in enhancing the size selectivity and reducing the amount of undersized P. longirostris caught in this fishery. RÉSUMÉDans cette étude, la sélectivité de la maille d'un cul de chalut tressé en polyéthylène pour la crevette rose de profondeur, Parapenaeus longirostris, a été étudiée en mer Egée. Les essais de pêche ont été menés par le chalutier commercial "Hapuloglu" entre le 9 et le 12 décembre 2006. Les données ont été collectées avec un cul de chalut tressé en lozenges, sur le chalut de maille 1200 utilisé commercialement. La taille moyenne des mailles du cul de chalut (mailles normalement de 46 mm) a été mesurée à près de 50 mm à l'aide d'un compas numérique. Les données de sélectivité ont été collectées par la méthode du double cul et analysées au moyen d'une équation logistique avec la méthode du Maximum de Vraisemblance. Les courbes de sélectivité moyenne ont été estimées à partir de traits uniques et ajustées en prenant en compte la variation entre les traits. La longueur de rétention à 50% et l'interval de sélection des P. longirostris (mâle + femelle) ont été estimées à 19,6 mm (longueur de la carapace) et 6,2 mm, respectivement, et il n'y avait pas de différence significative entre les valeurs de L 50 des mâles et des femelles (p < 0,05). Par conséquent, le cul

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