Parasitic worms of Acipenser stellatus, A. gueldenstaedtii, A. nudiventris and Huso huso (Chondrostei: Acipenseridae) from the southwest shores of the Caspian Sea

Sturgeons are the most important fish in the Caspian Sea, but there are only a few reports on their parasite communities in the southern part of this sea. In this study, a total of 93 individuals of four sturgeon species, namely Acipenser stellatus (n= 60), A.gueldenstaedtii (n = 12), A. nudiventris (n = 9) and Huso huso (n = 12), were caught in 2 geographical regions from the southwest of the Caspian Sea (Guilan Province, Iran) from March 2010 thtough May 2011. After recording biometric characteristics, standard necropsy and parasitological methods were used to identify parasites. Standard statistical computation (mean intensity, standard deviation, range, prevalence, abundance and dominance) were carried out for the overall samples and for samples grouped by season, geographical location, sex, length and weight. The differences between groups were determined by Kruskal Wallis test and Man Whitney U test (p< 0.05). Five worm species including 2 nematodes [Cucullanus sphaerocephalus and Eustrongylides excisus (L.)], 1 cestode (Bothrimonus fallax), 1 acanthocephalans (Leptorhynchoides plagicephalus) and 1 digenean trematode (Skrjabinopsolus semiarmatus) were found in A.stellatus, A. gueldenstaedtii, A. nudiventris and H. huso.