Selectivity of diamond and square mesh beam trawl cod ends for Parapenaeus longirostris (Lucas, 1846) (Decapoda, Penaeidae) in the Sea of Marmara

摘要: [In this study, the effects of an increase in diamond mesh size from 24 to 28 and 32 mm, changing shape square on selectivity for deep-water rose shrimp, Parapenaeus longirostris were investigated. Fishing trials carried out commercial beam trawlers various fishing areas Sea Marmara two periods, between August 8 September 2001, 29 April 9 May 2002. Data collected by twin trawl analysed means a logistic equation with Maximum Likelihood Method SELECT model. The 50% retention length (L 50) P. increased consistently sizes mm gave higher L 50 value than at same size. showed relatively better = 104.1 mm) other cod ends, agreeing Length First Maturity (LFM) 97 total length. use ends should be avoided order avoid catch consisting mainly small individuals. Such nets would contribute reducing amount undersized fishery. Dans cette etude, les effets d'une augmentation de la taille maille losange et le changement forme maille, carree, sur selectivite par rapport crevette ont ete recherches. Des essais peche realises des chaluts perche commerciaux dans diverses zones mer deux periodes, entre aout septembre avril mai donnees collectees l'aide jumeaux analysees au moyen logique avec methode du maximum vraisemblance modele SELECT. La augmente facon consistante vides mailles carrees donne une valeur plus elevee que pour meme maille. montre relativement meilleure 104,1 autres culs filet, en accord longueur totale premiere maturite mm. L'usage filet devrait etre evite eviter prise comportant principalement petits individus. Une telle filets contribuerait reduire quantite individus dessous exigee ce type peche., In (L50) L50 (L50 peche.]