Seasonal changes and host size-dependent variation in Diplostomum sp. Infection of some cyprinid fish

Some cyprinid fish species including leuciscus cephalus,chondrostoma regium,capoeta tinca,capoeta capoeta,barbus plebejus and cyprinis carpio were monitored for diplostomum sp. infection during one year period. in general,prevalence and mean abundance of diplostomum sp. was higher in l. cephalus,c. tinca,c. capoeta and b. plebejus during autumn and c. regium and c. carpio during spring. seasonal changes in the mean abundance of diplostomum sp. was also significantly higher in autumn in l. cephalus,c. tinca,b. plebejus and in spring in c. regium. parameters of infection of diplostomum sp. in three size classes of fish were also studied. mean abundance of diplostomum sp. was significantly higher in b. plebejus and c. tinca in fish >20.1 and in c. regium in fish >30 cm. furthermore,potential infection for fish farm located in almus dam lake was also discussed. © 2012 zoological society of pakistan.