Revision of Haliotrema species (Monogenea: Ancyrocephalidae) from Atlantic boxfishes (Tetraodontiformes: Ostraciinae): morphology, morphometrics, and distribution

Six species of Haliotrema, H. lactophrys, H. guadeloupensis, H. glandulosum, H. torridum, H. minutum, and H. kritskyi, found on the gills of seven species of Atlantic boxfishes (Ostraciinae) of the genera Acanthostracion and Lactophrys are redescribed. These species are found to be more similar to Haliotrema species on perciform hosts (i.e., Chaetodontidae, Labridae, and Mullidae) from the Caribbean than to congeners on other tetraodontiform hosts. In addition to clear morphological distinction, the results of a canonical discriminant analysis on 30 morphometric variables indicated that these variables also contribute, as a correlated group, to species distinction (p = 0.0001). The synergistic relation among the variables was identified as a shape component associated most strongly with the dorsal and ventral hamuli. The distributions of these parasite species indicated that none is specific to any one host species; specificity was more pronounced at the host genus level. Patterns of parasite distribution on host populations indicated a complicated distribution history.