Ectoparasites of the Blunt-Nosed Minnow (Hyborhynchus notatus)

Abstract

Previous to 1934 the taxonomy of American fresh-water Gyrodactyloidea received little attention. Investigations were directed more toward control measures with a minimum amount of effort devoted to specific diagnosis. In the above mentioned year Justus F. Mueller gave comprehensive consideration to the group and later wrote several papers with additional descriptions and records of new forms. The present writer (1936) published an abstract of a doctor's thesis in which he briefly described twelve new species of Tetraonchinae from the gills of Illinois fishes. To date fifty-four species of monogenetic trematodes of the subfamilies Gyrodactylinae, Dactylogyrinae and Tetraonchinae have been reported from the gills of North American fresh-water fishes. Eight of these belong to the genus Gyrodactylus, two to the genus Dactylogyrus, and forty-four to the subfamily Tetraonchinae. Including the three forms described in this paper the species of Dactylogyrus known to North America now total five. Of the above trematodes all are indigenous to North America except Tetraonchus monenteron (Wegener, 1857); Gyrodactylus elegans Nordman, 1832; and Dactylogyrus anchoratus (Dujardin, 1845). These three species were first described from Europe.