Acantholaimus Allgen 1933

Genus Acantholaimus Allgén, 1933

= Neochromadorina Kreis, 1963

Diagnosis. (Emended after Miljutin & Miljutina 2016) Spilipherinae. Head sensilla arranged in three (6+6+4) circles. Second and third circles may be close together. Anterior sensilla sometimes jointed. Body cuticle punctate, often with transverse rows of dots; lateral differentiation may be present as enlarged dots arranged irregularly, or more sparsely, or in transverse or longitudinal rows. Somatic setae may be present or absent. Fovea amphidialis large, round with interrupted posterior rim, nearly comma-shaped or spiral, wider than long. Buccal cavity armed with three or more solid teeth, teeth minute or large, often eversible. Twelve cuticular rod-shaped rugae in cheilostom. Ventral gland, secretory-excretory pore and nerve ring difficult to observe. Males with one outstretched testis and females with two antidromously reflexed ovaries. Spicules of a peculiar construction, flattened and strongly broadened proximally. Rod-shaped gubernaculum without apophysis and bifurcated at its distal end. Spermatozoa giant, pear-shaped, often structurally complex. No precloacal supplements. Tail long, filiform. Marine, mostly deep-sea. Number of species known: 51.

Type species: Acantholaimus longisetosus Allgén, 1933.

Species list. In this contribution, we adopted the list of known species of Acantholaimus provided by Miljuntin & Miljutina (2016).