A revision of species of the genus Haematoloechus Looss, 1899 (Trematoda: Haematoloechidae) from Canada and the United States

Abstract

KENNEDY, M. J. 1981. A revision of species of the genus Haematoloechus Looss, 1899 (Trematoda: Haematoloechidae) from Canada and the United States. Can. J. Zool. 59: 1836-1846. Previous experimental and field studies have shown that variations within the genus Haematoloechus may result from differences in age and degree of maturity, extent of crowding, species of host, and other factors. Based on these observations, only 6 of the 15 previously known species from Canada and the United States are considered valid. The valid species and their synonyms are as follows: Haematoloechus longiplexus Stafford, 1902; H. breviplexus Stafford, 1902;H. varioplexus Stafford, 1902 (= H. pamiplexus, = H. buttensis, = H. similiplexus, = H.jloedae, and H. uniplexus); H. kernensis Ingles, 1932 (= H. tumidus); H. medioplexus Stafford, 1902; and H. complexus (Seely, 1906) (= H. coloradensis, = H. confusus, = H. oxyorchis). The existence of three species groups is hypothesized. Haematoloechus longiplexus and H. breviplexus constitute one group, characterized by little geographical variation and a narrow host range. They are typically parasites of Rana catesbeiana and R. clamitans. Haematoloechus varioplexus and H. kernensis constitute the second group. These species have a wider host range and greater variation in characters purported to be specific differences. The third group includes those lung flukes which do not contain extracaecal loops (H. medioplexus and H. complexus). Of these, only H. medioplexus had little geographical variation and was found to occur in a single frog host. KENNEDY, M. J. 1981. A revision of species of the genus Haematoloechus Looss, 1899 (Trematoda: Haematoloechidae) from Canada and the United States. Can. J. Zool. 59: 1836-1846. Des Ctudes prkalables en laboratoire et en nature ont dCmontrC que les variations obsew6es chez le genre Haematoloechus peuvent rCsulter de differences d'ige, de degrC de maturitk, de densitk, du statut sp6cifique de l'hdte et d'autres facteurs. D'aprks ces observations, seulement six des quinze es@ces connues du Canadaet des Etats-Unis sont valides. Voici la liste des es@ces valides et de leurs synonymes:

Behavioral Basis of Second Intermediate Host Specificity among Four Species of Haematoloechus (Digenea: Haematoloechidae)

“…Adult flukes were dissected from wild-caught frogs and identified according to Kennedy (1981 Asellus intermedius were reared in the laboratory. All other arthropods used in the host specificity experiments were obtained from natural populations.…”

New species of Haematoloechus (Digenea: Plagiorchidae) in the lung of the foothill yellow-legged frog Rana boylii (Anura), from Humboldt County, California, USA

“…Kennedy (1980a) concluded that the degree to which the gonads are lobed was affected, in some instances, by ontogeny and deemed an 'unreliable' character; while sucker ratios, the extent of the uterine extracecal longitudinal loop, and position of the testes were 'most reliable' for species determination. Kennedy (1981) on the basis of this study and geographic variability in the widespread species H. longiplexus and H. breviplexus (Kennedy, 1980b), revised the genus, zealously lumping North American taxa into just 6 species. Haematoloechus buttensis, H. floedae, H. parviplexus, H. similiplexus, and H. breviplexus were all considered as junior synonyms of H. varioplexus.…”

Evidence of new species ofHaematoloechus(Platyhelminthes: Digenea) using partialcox1sequences

“…Morphological variability within species of this genus has caused controversy regarding species validity (Odening 1960;Prokopic and Krivanek 1974;Kennedy 1981). Kennedy (1981), e.g.…”