Some studies on plerocercoid of Schistocephalus sp. affecting Kawakawa (Euthynnus affinis) fish

Abstract

A total of 212 Kawakawa (Euthynnusaffinis) fish is a descriptive name and it's called with Balamyta in the Egyptian markets. From which,108 fish (group a.) were frozen as 65 fishes under the weight (wt.) of 3kg/fish, 43 over such weight. The rest 104 fish (group b.) collected freshly dead as 62 fishes under the wt. of 3kg/fish, 42 fish over such weight . Fish were collected from Dakahlia and Damietta markets during the period from Nov. 2014 up to April 2015 and also, through the period from May 2015 up to October 2015 for the frozen and freshly dead fish respectively. The study elucidate the presence of an intermediate host (plerocercoid larvae) of a genus, Schistocephalus as a cestode (tape worm) within the family Diphyllobothridae affecting Kawakawa (Kaw.) fish. Plerocercoid larvae were isolated from the abdominal cavity of the affected fish. Case of the affected frozen fish under the wt. 3kg/ fish revealed 3.07% and over the wt. 3kg/ fish showed 9.30%. While under the wt. 3kg/ fish was 4.83% and over the wt. of 3kg/ fish showed 11.90% in the freshly dead fish. Musculature, internal organs and tissues in the abdominal cavity of the affected freshly dead fish were showed fried and dark brown colour. Histopathological findings revealed multiple deposits of haemosiderin as spots within the liver of the affected freshly dead fish and vacuolation of the muscle fibers. Besides,scanning electron Microscopy (SEM) exhibited the larval morphological outline which clarify the plerocercoid Schistocephalus sp. of the family Diphyllobothridae.