Metazoan parasites of the common carp (Cyprinus carpio L., 1758) from Tahtali Dam Lake (Izmir).

OBJECTIVE: The aim of this study was identification of the parasites of the common carp from Tahtali Dam Lake. METHODS: The fish were transported live to the laboratory. They were investigated for ectoparasites and endoparasites. The parasite specimens were fixed and identified. RESULTS: During the study, 47 common carp were caught monthly and 3 species of metazoan parasites were found: Dactylogyrus extensus (Monogenea), Contracaecum sp. larvae (Nematoda) and Lernaea cyprinacea (Crustacea). CONCLUSION: The parasite species were new records for Tahtali Dam Lake. Contracaecum sp. larvae were recorded for the first time from Cyprinus carpio in Turkey.

Effects of 2,4-dichlorophenoxyacetic acid formulation on medulla spinalis of Poecilia reticulata: a histopathological study.

This study investigated the possible effects of a commonly used foliar herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) formulation on medulla spinalis of lebistes. Fish were exposed to 2,4-D (15, 30, 45 mg L(-1)), behavioral changes were monitored. Fish were fixed, histopathological examination was carried out on sections taken from the upper parts of the fish body. Histopathology showed increase in neuronal loss, swelling indicating formation of intracellular edema, vacuolization noticed as the formation of vacuoles within or adjacent to cells, deformation in the Nissl granules, pyknosis and gliosis in medulla spinalis. Behavioral changes were decreased general activity, grouping, shortness in breath, sudden rotations and jumping, loss of equilibrium and colour. In conclusion, this commercial formulation of 2,4-D is considerably neurotoxic to lebistes. Fish constitute the last link in the chain of the feeding cycle in aquatic eco-system, number of studies investigating acute and chronic neurotoxicity of various herbicides in fish should be increased.