Neophasis oculata (Chubrik, 1966)

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 : 165-166

3.3.3. Sexual adults of Neophasis oculata ( Fig. 5G )

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

Host: Shorthorn sculpin Myoxocephalus scorpius .

Other reported hosts: 40 fish species (summarized in Bray and Gibson, 1991).

Sites: Pyloric ceca, intestine.

Prevalence: 44% (27 of 61).

Intensity (range of values, mean and standard error of the mean): 1–183 (12.9 ± 8.70).

Vouchers: Hologenophore VG 5.2 (isolate 2) and paragenophores (NO002, NO003) corresponding to isolates No 2 and 3 deposited in the collection of the Department of Invertebrate Zoology of Saint Petersburg University .

Description: Measurements in Table 3.

Remarks: We found sexual adults of N. oculata in M. scorpius in the White Sea throughout the observation period. Ovigerous specimens were detected mostly in July. The most common infection site was

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IB-VS. Distance from intestinal bifurcation to anterior margin of ventral sucker. Vit-VS. Distance from anterior-most extent of vitelline fields to anterior margin of ventral sucker

VS-Ovary.Distance from posterior margin of ventral sucker to anterior margin of ovary.

PTR. Length of post-testicular region.

C-PE. Distance from posterior-most extent of the intestinal caeca to posterior extremity of worm.

pyloric ceca. In heavily infected fish, the worms were also found in the other regions of the digestive tract such as the stomach, the midgut and the hindgut.

Figures

Fig. 5. Neophasis oculata metacercariae (A–F) and sexual adult (G). (A) General view of metacercaria (acetic carmine, DIC). (B–C) Histological sections, Mallory’s trichrome stain, encysted metacercaria (B) and some of its inner structures (C). (D–F) SEM, ventral view (D) and magnified spines in the anterior (E) and posterior (F) regions. (G) Sexual adult (acetic carmine, DIC). Scale bars – 100 μm on A, B, D, G; 50 μm on C; 10 μm on E, F.Abbreviations: c – ceca; ci – cirrus; eg – eggs; ev – excretory vesicle; icy – inner cyst layer; ocy – outer cyst layer; os – oral sucker; ot – ootype; ov – ovary; pe – pigmented eyespots; ph – pharynx; sv – seminal vesicle; te – testes; ut – uterus; vi – vitelline follicles; vs – ventral sucker.