Blood Values of Some Helminth-Infected Aquacultured Fishes

Abstract

Erythrocytes, thrombocytes, lymphocytes and neutrophils were the principal blood cell types found in the blood of Clarias batrachus, Ophicephalus striatus, Oreochromis mossambicus and Oreochromis niloticus. Eosinophils and basophils were observed in Ophicephalus striatus but were absent in Clarias batrachus. Eosinophils but no basophils were seen in Oreochromis mossambicus and Oreochromis niloticus. Along with mature erythrocytes, immature, dividing, senile, and disintegrated erythrocytes were also observed from the circulating blood of the four fish species.

From Clarias batrachus, eight species of helminths were recovered, namely, Cichlidogyrus sclerosus, Actinocleidus sp., Phyllodistomum sp., Opegaster minima, Gauhatiana batrachii, Bovienia serialis, Procamallanus darius, and Philometra sp. The parasites recovered from Ophicephalus striatus were Diplostomulum sp., Camallanus ophicephali, Arqulus indicus, and Lernaea cyprinacea. Cichlidogyrus sclerosus and Transversotrema laruei were collected from Oreochromis mossambicus and Oreochromis niloticus; from the latter, Gyrodactylus medius was also recovered. The average parasite burden was generally low.

Parasitized and unparasitized fishes were active and appeared healthy. Blood values of parasitized fishes showed few significant differences from those of unparasitized fish groups. No parasitized fish group showed significant reduction in mean hematocrit and RBC count or significant increase in mean WBC count and mean % neutrophils in comparison with unparasitized group of the same fish species.