Atractidae, Railliet, 1917

Moravec, František & Jirků, Miloslav, 2017, Some nematodes from freshwater fishes in central Africa, Folia Parasitologica (033) 64, pp. 1-39 : 3-5

Atractidae gen. sp. fourth-stage larva Fig. 3

Description (1 female larva). Small whitish nematode 2.2 mm long, 111 wide, with smooth cuticle; very narrow lateral alae extend along body. Cephalic end rounded, 24 wide, bearing 4 small cephalic papillae. Oesophagus 468 long; its anterior portion long, narrow, 15–18 wide; short posterior portion somewhat broader, longitudinally oval, 75 long and 33 wide, provided inside with small sclerotised apparatus ( Fig. 3A ). Intestine narrow, straight. Nerve ring and excretory pore 186 and 291, respectively, from anterior extremity. Developing vulva postequatorial, 1.5 mm from anterior end of body (at 70% of body length). Tail conical, 202 long ( Fig. 3B ).

Host: North African catfish Clarias gariepinus (Burchell) (Siluriformes: Clariidae ).

Site of infection: Intestine (distal part).

Locality : Lower Congo River, Democratic Republic of the Congo – unspecified locality in Bas Congo ( Congo basin, collected 10 July 2008) .

Prevalence and intensity: 1 fish infected/2 fish examined; 1 nematode.

Deposition of voucher specimen: IPCAS N-1137.

Remarks. The general morphology of this female larva, especially the presence of a distinct sclerotised apparatus inside the bulbous posterior portion of the oesophagus, indicates that it belongs to the Atractidae . Recently Moravec and Van As (2015a) reported a nongravid female designated as Atractidae gen. sp. from the intestine of the catfish Schilbe intermedius Rüppel (Schilbeidae) in Botswana, which, however, differs from the present specimen in a larger body, a distinct pharyngeal portion of the oesophagus and isthmus and in the location of the vulva in the anterior part of the body.

Figures

Fig. 3. A, B – Atractidae gen. sp. larva from Clarias gariepinus (Burchell) (anterior and posterior body ends, lateral views).