Resumen
Wild rabbit fish(Siganus rivulatus)Forsskål (Teleostei, Siganidae), a herbivorous fish were caught from Suakin near Sudanese Red Sea during February 2010 - January 2011, which were examined for histo-pathological alterations in small intestine infected by a helminthes parasite (Sclerocollum sp.). Sclerocollum sp. was reported for the first time from Suakin near Sudanese Red Sea. Effect of a parasite included: abundance of lymphocytes cell, eosinphils, red blood cells and goblet cells in parasitized intestine; which were significantly more than intestine devoid of infection. The histopathologicaly study indebted that the worms damaged the architecture of intestinal tissues besides hemorrhage, hyperplasia in mucosa and submucosa, melanomacrophage aggregation and necrosis of mucosa and sub-mucosal layer. The 237 fishes (Siganus rivulatus) caught for investigation the helminthes parasite. The condition factor of healthy fishes was 2.94±0.03, which was highly significantly different value (p< 0.02) compared to helminthes fish (2.81±0.04). The prevalence of infection was observed in 38% of fishes. A direct damage by Sclerocollum sp in the form of destruction of villi, hemorrhage, fibrotic capsule round proboscis, erosion of submucosa along parasites capsule, and separation of submucosa from mucosa, was observed. DOI: http://dx.doi.org/10.3126/ije.v3i2.10531 International Journal of the Environment Vol.3(2) 2014: 216-228