Cosmocephalus obvelatus (Creplin, 1825) Seurat 1919

* Cosmocephalus obvelatus (Creplin, 1825) Seurat, 1919

Description (after Wong & Anderson 1982). In the apparent absence of a description of L3 from fishes the

following is based on Wong & Anderson’s (1982) account of L3 from experimentally infected amphipods. L3 are

2.05 (1.63–2.40) long, and 0.071 (0.058–0.095) wide. Head with two triangular pseudolabia and four submedian

cephalic papillae (Fig. 69 A). Amphids small. Buccal cavity long and narrow but expanded in oral region. Pair of

inconspicuous deirids immediately behind nerve ring. Excretory pore opens 0.16 (0.14–0.19) from anterior end

(Fig. 69 B). Total oesophagus [muscular plus glandular portions] 1.15 (0.99–1.40) long. Rectum tubular with thick

cuticle. Tail tip rounded. Pair of large phasmids subventrally (Fig. 69 C). Genital primordium of males a simple tube

lying free in pseudocoelom; that of females a similar tube but attached to body wall by vaginal primordium (Fig.

69D).

Site: mesenteries

Hosts: Apeltes quadracus (2); Carassius auratus (1); Cottus sp. (1); Fundulus heteroclitus (3); Gasterosteus aculeatus (1, 2); Notropis hudsonius (1); Notropis sp. (1); Oncorhynchus mykiss (1); Osmerus mordax (1); Pungitius pungitius (2, 3); Semotilus atromaculatus (1)

Distribution: Nova Scotia, Ontario

Records: 1. Wong & Anderson 1982 (EX, ON); 2. Marcogliese 1992b (NS); 3. Marcogliese 1995b (NS)