Henneguya doori Guilford, 1963 (Myxosporida) of Perca flavescens in New Brunswick

Abstract

Of the Perca flavescens collected during winter from Little Magaguadavic Lake, New Brunswick, 34% were infected with Henneguya doori Guilford, 1963. Cysts were on the primary gill lamellae and formed white nodules (0.5 to 0.9 mm in size) that contained dense masses of mature spores. Most cysts were in septal tissue near the afferent artery (inflowing blood) and a few were in secondary lamellae. Cysts were absent from septal tissue that surrounded the efferent artery (outflowing blood). This distribution suggests that infective trophozoites enter the primary gill lamellae via the afferent artery and then migrate through the endothelium and develop in the septal tissue. Some infective trophozoites appear to enter secondary lamellae but possibly because of the small diameter of the capillaries do not reach the efferent artery and thus develop in the capillary bed.Mature spores found in the present study are morphologically similar to spores of H. doori described from Lake Michigan. Henneguya doori occupies the same tissue in the same host species as Henneguya percae Fantham, Porter, and Richardson, 1939, and spores of the two species have some morphological similarities. It is concluded that H. doori may be a synonym of H. percae.