Neophasis anarrhichae (Nicoll, 1909) Bray, 1987

Kremnev, Georgii, Gonchar, Anna, Krapivin, Vladimir, Uryadova, Alexandra, Miroliubov, Aleksei & Krupenko, Darya, 2021, Life cycle truncation in Digenea, a case study of Neophasis spp. (Acanthocolpidae), International Journal for Parasitology: Parasites and Wildlife 15, pp. 158-172 : 167

3.3.5. Sexual adults of Neophasis anarrhichae ( Fig. 7J )

Locality: White Sea; Keret Archipelago (Kandalaksha Bay).

Host: Atlantic wolffish Anarhichas lupus .

Other reported hosts: A. denticulatus , A. minor (summarized in Bray and Gibson, 1991).

Site: Intestine.

Prevalence: 77% (17 of 22).

Vouchers: Paragenophores (NA001-NA003) corresponding to isolates No 20 and 21 deposited in the collection of the Department of Invertebrate Zoology of Saint Petersburg University .

Description: Measurements in Table 3.

Remarks: The number of parasites per fish ranged from less than ten to more than 5000 individuals. We found ovigerous sexual adults of N. anarrhichae in A. lupus throughout the observation period. The most common infection site was the upper midgut. The number of parasites diminished towards the end of the midgut. In heavily infected fish sexual adults were also found in the hindgut, though in lesser numbers than in the midgut. A few immature specimens were sometimes seen in the stomach.

Figures

Fig. 7. Neophasis anarrhichae successive life cycle stages. (A, B) whole mounts (toluidine blue, DIC) of the anterior end of daughter redia (A) and cercaria embryo (B). (C) Cercaria later embryo, CLSM, TRITC-phalloidin and phospho Y antibody staining. (D, E) whole mounts (toluidine blue, DIC) of cercaria (D) and metacercaria (E). (F) Anterior end of metacercaria with gland ducts, CLSM, acetylated α-tubulin and phospho Y antibody staining. (G) Sagittal section of metacercaria, Heidenhain’s iron hematoxylin staining. (H) Sagittal section of metacercaria, Mallory’s trichrome stain. (I) progenetic metacercaria (toluidine blue, DIC). (J) sexual adult (acetic carmine, DIC). Scale bars – 50 μm.Abbreviations: aс – anterior collecting duct; bp – birth pore canal; c – ceca; cd – caudal excretory duct; ci – cirrus; eg – eggs; ev – excretory vesicle; os – oral sucker; ot – ootype; ov – ovary; ovd – oviduct; pс – posterior collecting duct; pe – pigmented eyespots; pd – penetration gland ducts; ph – pharynx; sv – seminal vesicle; t – tail; te – testes; vi – vitelline follicles; vs – ventral sucker. Arrow indicate on site of main collecting duct division.. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)