Report of ectoparasitic protozoans from gill of imported common catfish, Hypostomus plecostomus in Iran

Objective: Common catfish; Hypostomus plecostomus is one of the most popular freshwater aquarium fish, which can be found in about 90% aquaria, mainly for their cheap price, role in aquaria (scavenging), resistant to water temperature changes (20-30ºc) and especially their adaptation with other fishes. This resulted in the large-scale importation to Iran. It is important to have parasite-free aquarium fishes. Some parasites have a direct life-cycle and can transmit without any intermediate host, that it causes economical loss and noticeable mortality among the fishes. In this study some ectoparasitic protozoan are reported from common catfish. Method & Materials: One hundred imported catfish (common pleco) from southeast Asia, that were held in 100 litres aquarium at 24ºc, that were studied in fish lab of Veterinary Medicine Faculty. Stereo microscope and wet mount observations were done on gills. First the parasites were found by wet mount and fixed by giemsa stain, then photo/film was taken by light microscopy from the parasites to confirm the genus through size and morphologic characteristics. In stereo microscopy, we used gill filaments and archs, then after finding any genus of parasites we counted their average quantity in each arch. Results & Conclusion: A total of 100 plecos’ gill archs was examined under microscope, representing two ciliated protozoa parasites: Ichthyophthirius (ich) and Trichodina. On these fish, forty-three trichodinid parasites and thirty-four Ichthyophthirius were observed. In twenty-four plecos, both parasites were found. Literature review showed no article about these two parasites in Hypostomus plecostomus. Ectoparasitic protozoa are among the most important parasites of fish especially in aquaria. Their life cycles range from simple binary fission to the production of freeswimming, ciliated infective stages. Ich is one of the most common diseases of freshwater fish. Virtually all freshwater fish are susceptile to infection. Under aquarium conditions, it is particularly virulent. Predominant signs include small white spots over the body and gills. Parasite has a complex life cycle that includes stages on the host and in the environment. The development of the parasite is very temperature dependant; 3-4 days at 22ºc, up to 11 days at 15ºc, 30 days at 10ºc.Trichodinids are the most common ectoparasite of both freshwater and marine fishes and frequent in fish that are stressed (poor nutrition, overcrowding in aquaria,…).

کلیدواژه ها:

Ich ، Trichodina ، Common catfish ، Protozoa ، Parasite ، Iran