Leech infection in grouper (Epinephelus coioides) in the Philippines

Abstract

The effect of infection with the leech Zeylanicobdella arugamensis on the hematological parameters in orange-spotted grouper (Epinephelus coioides) was determined. The hematocrit, hemoglobin and total plasma protein of leech-infected grouper were significantly lower than uninfected fish indicating anemia. The blood, kidney and spleen smears of grouper infected with the leech and smears of the leech’s proboscis, however, did not show any associated blood protozoan. The possible explanations on the absence of blood-parasitic protozoans are discussed.