Investigation of helminthic parasites in North Caucasian bleak (Alburnus hohenackeri), Transcaucasian white bream (Blicca bjoerkna) and Sharpbelly (Hemiculter leucisculus) in the eastern basin of Anzali wetland

In this study, helmintic parasites in Alburnus hohenackeri, Blicca bjoerkna and Hemiculter leucisculus of Anzali wetland were examined. Seasonal sampling (spring to winter 2019), was performed using beach net and Fyke net of micro-springs (8-12 mm) from 3 stations of Shijan, Pirbazar and Pasikhan located in the eastern basin of Anzali wetland. After transferring the fish samples to the laboratory, biometry, sex identification and age determination were performed and examined for parasitic infection. Valid diagnostic keys were used to identify the observed parasites. ،he Highest mean weight and length belonged to H. leucisculus (7.39 ± 7.37189 g and 9.27 ± 3.109437 cm) and the lowest belonged to A. hohenackeri (5.86 ± 2.901398 g and 8.05 ± 1.092695 cm). As a result of this study, 6 species of parasities include: Gyrodactylus sp., Dactylogyrus sphyrna, Dactylogyrus sp., Diplostomum spathaceum, Rhabdochona denudata and Ligula intestinalis were identify and isolated. B. bjoerkna were infected with 4 species and other fish were infected with 3 species of observed parasites. Contamination of B. bjoerkna to Gyrodactylus sp., A. hohenackeri to L. intestinalis and also Contamination of this species and B. bjoerkna to R. denudata is reported for the first time from Anzali Wetland. Accorrding to the chi-square test between various infections and parameters of sex, age, weight, length, seasons and the various stations, there was no statistically significant difference (p>0.05). Similar to recent research, despite the diversity of identified parasites, the average intensity and frequency of most parasites in the studied fish in Anzali wetland was very low and negligible. Among the identified parasites, D. spathaceum eye parasite was the most common infection and Monogenes with 2 genera and 3 species had the highest species abundance. B. bjoerkna was the most infected fish in Anzali wetland compared to other species studied. According to the research background, a report of contamination of B. bjoerkna with Gyrodactylus sp. And R. denudata as well as contamination of A. hohenackeri with L. intestinalis and R. denudata were not recorded in Anzali wetland before this study. If the fish of Anzali wetland enter the fish ponds around it, there is a possibility of transferring parasites to farmed fish and a negative impact on production efficiency. Installation of suitable filters in the ponds water inlet as a preventive method should be seriously considered by fish breeders.