Occurrence and intensity of some nematodes in the bonyfish species of the Caspian Sea and its basin

The fisheries of bonyfishes are of commercial importance in the southern part of the Caspian Sea, but there are few reports about their pathogens in this area. In the present study, a total of 983 samples of fifteen fish species, including Esox lucius (n=167) , Carassius carassius (n=42), Abramis brama orientalis (n=50) , Perca fluviatilis (n=155), Chalcalburnus chalcoides (n=51), Tinca tinca (no=70), Scardinius erythrophthalmus (n=119), Barbus capito (n=5) , Aspius aspius (n=5), Silurus glanis (n=69), Neogobius fluviatilis (n=43), N. kessleri (n=14), N. caspius (n=33), N. melanostomus (n=10), N. bathybius (n=24) and Salmo trutta m. fario (n=126) were taken from some water resources in the south- west of the Caspian Sea (Guilan province, Iran) from September 2001 to October 2003. After recording biometric characteristics of the fishes, standard necropsy and parasitology methods were used for finding the parasites. The nematodes were fixed in 70% ethyl alcohol, cleared in lactophenol and then identified by parasite identification keys. Standard statistical computations (mean, standard deviation, range and prevalence) were carried out by Microsoft Excel (Office 2000). In the present study, seven nematode species were found in the fifteen fish species: Raphidascaris acus was found in E. lucius, P. fluviatilis and S. glanis; R. acus larvae were found in C. carassius, T. tinca, A. brama orientalis and S. erythrophthalmus; Eustrongylides excisus (L) was found in E. lucius, P. fluviatilis, S. glanis, N. fluviatilis, N. kessleri, N. caspius, B. capito and A. aspius; Anisakis sp. (L) was found in C. chalcoides, N. bathybius and B. capito; Camallanus lacustris was found in P. fluviatilis, E. lucius and T. tinca; Dichelyne minutus was found in N. fluviatilis, N. kessleri, N. caspius, N. melanostomus and N. bathybius; Raphidascaroides sp. (L) was found in S. glanis; Cystidicoloides ephemeridarum was found in Salmo trutta m. fario.

nematodes, bony fish, Caspian sea