the identification and study of monogenetic parasites in the gills of wild and cultured yellow-fin seabreams (acanthopagrus latus houttuyn, 1782) in persian gulf coasts

monogenetic termatodes are exoparasites of iranian freshwater fishes with high pervalency in both wild and cultured fishes which cause economoic loss each year. the aim of the present study was to detect parasites of gills in yellow- fin seabreams of persian gulf. this study was conducted for one year (between autumn 2007 to autumn 2008) on both wild and cultured yellow-fin seabreams of persian gulf. 276 fishes were studied and two species of monogenetic trematodes, polylabris angifer and lamellodiscus acanthopagri, were identificated. infestation and intensity rates for polylabris angifer in all seabreams were 12.3% and 2.76±2.62% respectively. infestation rate and intensity rates in cultured fishes of hengam island were 12.5% and 2.43±0.78% and in imam port were 60% and 6.50±3.98% respectively. the highest and lowest rates of infestation with polylabris angifer were found in spring and autumn respectively. the highest infestation intensity was found in summer. the infestation rate and it's intensity with lamellodiscus acanthopagri in all wild and cultured seabreams were 6.5% and 6.33±5.73% and in cultured fishes in imam port were 60% and 5.50 ± 2.07% respectively. this parasite didn't find in the cultured fish of hengam island. there was a direct positive relation between weight and infestation rate. the pathological signs of polylabris angifer infestations are as increase in goblet cells, haemorrhage, dilatation of primary lamella and adhesion of secondary lamella.