Hyptiasmus tumidus, Kossack, 1911

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 : 64-65

H. tumidus Kossack, 1911

Syns. H. chengduensis Zhang, 1985 ; H. sichuanensis Zhang, 1985 Type host. Greylag goose, Anser anser (Linnaeus) ( Anseriformes : Anatidae ).

Type locality. Germany; specific type location unknown.

Additional hosts. Unidentified Anatidae (“Duck, geese.”)— Zhang et al. (1985).

Additional localities. Chengdu, Guang’gan Prefecture, Sichuan Province, People’s Republic of China— Zhang et al. (1985).

Remarks. Considered to be a synonym of H. laevigatus Kossack, 1911 by Bashkirova (1950); and of H. arcuatus ( Brandes, 1892 of Stossich, 1902) by Joyeux & Baer (1927). Specimens used in the original description of this species were from the Berlin Museum. Hyptiasmus chengduensis ( Fig. 2 of Zhang et al. 1985) was originally described along with H. sichuanensis ( Fig. 1 ) from unidentified anatids (duck and geese) from the same general locality in China. The illustrations of these two species appear to indicate that the specimens had become somewhat distorted and contracted during fixation, causing some abnormal folding and outpocketing of the ceca. Although H. chengduensis and H. sichuanensis were described as being quite similar in size (17,000–24,000 and 15,040– 23,500, respectively) the illustrations in the original description show them as being dissimilar in size. Further, calculations of their lengths using the 5mm scale on the plate of Zhang et al. (1985) yields much smaller sizes than given in the descriptions (2,398 and 1,670, respectively). The only apparent differences between these two species appears to be that H. chengduensis has less folding of the ceca and the intertesticular ovary is not in line with the two testes. It should be noted in Fig. 2 of H. chengduensis that in addition to the ovary being placed to the left of the posterior testis, the anterior testes is contiguous with the left cecum and the left cecum is situated closer to the body wall than the right cecum. This suggests that the posterior extremity was rolled during fixation, which might account for the differences seen in the placement of the ovary in this species as compared to H. sichuanensis . In our opinion, these are the same species and as noted by the authors they are very similar to H. tumidus . These two species cannot be distinguished from H. tumidus and H. tumidus also was described from a goose. We consider both H. chengduensis and H. sichuanensis to be synonyms of H. tumidus . No oral or ventral sucker described— Kossack (1911) and Zhang et al. (1985).

Figures

FIGURES 1 – 4. Diagrammatic representations of species representing the genera assigned to Cyclocoelinae Stossich, 1902. 1. Cyclocoelum Brandes, 1892 represented by Cyclocoelum mutabile (Zeder, 1800), adapted from Kossack (1911); 2. Selfcoelum Dronen, Gardner, & Jiménez, 2006 represented by Selfcoelum limnodromi Dronen, Gardner, & Jiménez, 2006, adapted from Dronen et al. (2006 a); 3. Psophiatrema Dronen & Kinsella, 2009 represented by Psophiatrema greineri Dronen & Kinsella, 2009, adapted from Dronen & Kinsella (2009); 4. Circumvitellatrema Dronen, Greiner, Ialeggio & Nolan, 2009 represented by Circumvitellatrema momota Dronen, Greiner, Ialeggio & Nolan, 2009, adapted from Dronen et al. (2009). Abbreviations: C, cecum; G, genital pore; O, ovary; P, pharynx; S, rudimentary oral sucker; T, testis; U, uterus; V, vitelline field.