Leptosomatidae Filipjev, 1916, 2010

Zograf, Julia K., Semenchenko, Alexander A. & Mordukhovich, Vladimir V., 2024, New deep-sea species of Aborjinia (Nematoda, Leptosomatidae) from the North-Western Pacific: an integrative taxonomy and phylogeny, ZooKeys 1189, pp. 231-256 : 231

Family Leptosomatidae Filipjev, 1916

Diagnosis

( Smol et al. 2014; emended). Large nematodes (up to 172 mm). Six inner labial sensilla mostly papilliform, six outer labial and four cephalic sensilla papilliform or setiform. Amphids pocket-shaped. Large number of metanemes with caudal filament usually present: dorsolateral and ventrolateral or only dorso-lateral orthometanemes and loxometanemes of type I. Many species with ocelli. Buccal cavity narrow, sometimes with tooth-like thickening. Pharynx inserts into the body cuticle in the region of buccal cavity, the cephalic capsule is variable in the form. Three pharyngeal glands open in the buccal cavity. Pharynx always smooth in outline. Secretory-excretory system, if present, usually restricted to the pharyngeal region, may consists of two cells. Female reproductive system didelphic-amphidelphic with antidromously reflexed ovaries. Males with two testes opposed. Gonad positions relative to intestine variable in species, with anterior and posterior gonad position reversed. Subventral or ventral precloacal papillae (never tubules) often present. Caudal glands mostly present, extending into the precaudal region. Marine and parasites of marine invertebrates.