Ecology and taxonomy of ectoparasites infecting sympatric Fundulus heteroclitus, F. diaphanus and their asexual hybrid in two Nova Scotian lakes

Abstract

The ectoparasites infecting Fundulus heteroclitus (L.), F. diaphanus (LeSueur), and their asexual hybrid from the brackish waters of Porters Lake and Lawrencetown Lake were studied. Research focused on parasite distribution across host species, parasite distribution with respect to salinity, and the taxonomy of viviparous monogeneans. Eight species of parasite were found: the branchiurid Argulus funduli , the leech Myzobdella lugubris, the copepod Ergasilus manicatus, the egg-laying monogenean Salsuginus sp. and the viviparous monogeneans Gyrodactylus stephanus, Fundulotrema prolongis, F. foxi and F. porterensis. All species of parasites infected all fundulid hosts with overall infections (I[subscript pi] ) being highest on F. heteroclitus, lowest on F. diaphanus, and hybrids consistently exhibiting intermediate infections. With respect to salinity no clear overall trends were observed. Taxonomic study of the gyrodactylids revealed a previously undescribed species (F. porterensis , and clarified the taxonomy of the additional gyrodactylids using traditional morphology, scanning electron microscopy and rDNA sequence data.