Cyclocoelum robustum, Stossich, 1902

Dronen, Norman O. & Blend, Charles K., 2015, Updated keys to the genera in the subfamilies of Cyclocoelidae Stossich, 1902, including a reconsideration of species assignments, species keys and the proposal of a new genus in Szidatitreminae Dronen, 2007, Zootaxa 4053 (1), pp. 1-100 : 17

C. robustum Stossich, 1902

Type host. Tufted duck, Aythya fuligula (Linnaeus) (Syn. Fuligula cristata Linnaeus) ( Anseriformes : Anatidae ).

Type locality. Europe; specific type locality unknown.

Additional hosts. Species of Aythya Boie (Syn. Fuligula [Linnaeus]); tufted pochard, Nyroca fuligula (Linné) (Syn. A. fuligula ); graylag goose, Anser anser (Linnaeus) ( Anseriformes : Anatidae ) — Yamaguti (1971).

Additional locality. Republic of Kazakhstan; Siberia, specific localities unknown — Yamaguti (1971).

Previously proposed synonyms. Hyptiasmus magnus Johnston, 1917 (= Prohyptiasmus magnus [ Johnston, 1917])— Bashkirova (1950); Prohyptiasmus robustum ( Stossich, 1902) — Feizullaev (1980).

Remarks. This species was originally named Cyclocoelum robustum Stossich, 1902 , but only a body length and body width was provided in the original description. It was transferred to Prohyptiasmus Witenberg, 1923 by Witenberg (1923) where Prohyptiasmus robustus ( Stossich, 1902) was designated as the type species for the genus, but neither an adequate redescription nor illustrations were provided—Bashkirova (1950); Yamaguti (1971). Witenberg (1926) provided a representative diagram of a species of Prohyptiasmus in his Table 2 , which apparently was presumed to represent P. robustus (= Cyclocoelum robustum )— Yamaguti (1971, Fig. 1141). The diagram of Witenberg (1926) shows the species to have an intertesticular ovary that is in a straight line with two tandem testes (Hyptiasminae), a prepharyngeal genital pore and the vitelline fields are not confluent posteriorly, and it would be assigned to Hyptiasmus Kossack, 1911 as suggested by Kossack (1911). Witenberg (1928) placed this species in Harrahium Witenberg, 1926 , thus removing it as the type species for Prohyptiasmus and proposed a replacement genus, Stossichium Witenberg, 1928 with S. magnum ( Johnston, 1917) as the type species. However, C. robustum , as originally described by Stossich (1902), has an intertesticular ovary, forming a triangle with the testes ( Fig. 11 of Stossich 1902) (Cyclocoelinae), a prepharyngeal genital pore ( Fig. 12 ) and the vitelline fields are not confluent posteriorly ( Fig. 11 ), placing it in Cyclocoelum . No oral or ventral sucker described—Stossich (1902).

Figures

FIGURES 10 – 13. Diagrammatic representations of species representing the genera assigned to Hyptiasminae Dollfus, 1948. 10. Hyptiasmus Kossack, 1911 represented by Hyptiasmus arcuatus (Brandes, 1892 of Stossich, 1902), adapted from Kossack (1911); 11. Prohyptiasmus Witenberg, 1923 represented by Prohyptiasmus magnus (Johnston, 1917), adapted from Johnston (1917); 12. Allopyge Johnston, 1913 represented by Allopyge antigones Johnston, 1913, adapted from Johnston (1913); 13. Morishitium Witenberg, 1928 represented by Morishitium texanense Dronen, 2007, adapted from Dronen (2007 a). Abbreviations: C, cecum; G, genital pore; O, ovary; P, pharynx; S, rudimentary oral sucker; T, testis; U, uterus; V, vitelline field.