Taxonomic Revision of Spirorchis MacCallum, 1919 (Digenea: Spirorchidae)

Abstract

Spirorchis MacCallum, 1919 (Schistosomatoidea: Spirorchidae) is reviewed based on examination of available type material. Eight valid species are recognized: Spirorchis innominatus Ward, 1921 (type species); Spirorchis artericola (Ward, 1921); Spirorchis elegans Stunkard, 1923; Spirorchis haematobius (Stunkard, 1922); Spirorchis kirki (Platt, 1990); Spirorchis minutus Byrd, 1939; Spirorchisparvus (Stunkard, 1923); and Spirorchis scripta Stunkard, 1923. Spirorchis innominatus is considered the valid name for the genotype and Spirorchis eustreptos MacCallum, 1921, is regarded as a junior objective synonym. Spirorchis pseudemyae Byrd, 1939, appears to be a senescent form of S. artericola and is reduced to a junior subjective synonym of that species. Spirorchis elegans from the esophageal submucosa of emydid turtles is considered a stable phenotype and therefore not a synonym of S. scripta as suggested by previous authors. No postovarian testis was found in an examination of Spirorchis blandingioides Byrd, 1939, therefore, it is regarded as a synonym of S. scripta. Spirorchis elephantis (Cort, 1918), Spirorchisparvus sensu Wall, 1941 nec Stunkard, 1923, and Spirorchis magnitestis Byrd, 1939, are considered species inquirendae. Spirorchis neurophilus Fisher, 1968, was first proposed in a thesis and does not meet the criteria for publication as established by the International Code of Zoological Nomenclature (Art. 9). A key to the species of Spirorchis is provided.