Apomatus Philippi, 1844

Kupriyanova, Elena K. & Flaxman, Beth, 2024, Serpulidae (Annelida) of the Australian Indian Ocean Territories, Records of the Australian Museum (Rec. Aust. Mus.) 76 (4), pp. 211-242 : 216

Genus Apomatus Philippi, 1844

Types species. Apomatus ampulliferus Philippi, 1844

Generic diagnosis (after Kupriyanova & Nishi, 2010). Tube white, opaque, circular in cross-section, keels and collar-like rings absent. Granular overlay may be present. Operculum a soft membranous vesicle without endplate borne on unmodified pinnulated radiole. Opercular constriction may be present. Pseudoperculum may be present on unmodified radiole. Radioles may be exceptionally flat ribbon-like. Arrangement of radioles in semi-circles (may be up to ¾ of a circle), maximum number up to 40 per lobe in larger species. Inter-radiolar membrane present. Radiolar eyes present. Stylodes absent. Mouth palps present. Seven thoracic chaetigerous segments. Collar trilobed or unlobed with smooth edge. Thoracic membrane long, forming ventral apron across anterior abdominal segments. Tonguelets between ventral and lateral collar lobes absent. Collar chaetae limbate, of two sizes (thus, in the classical terminology capillary and limbate), may exceptionally be supplemented by Apomatus chaetae. Apomatus chaetae usually present from chaetiger 3 onward. Thoracic uncini saw-to-rasp-shaped with approximately 30 teeth in profile, up to 3 (exceptionally 4) teeth in a row above and continuing onto peg; anterior peg very long, blunt, almost rectangular. Ventral thoracic triangular depression absent. Abdominal chaetae sickle-shaped with finely denticulate blades; uncini rasp-shaped with approximately 30 teeth in profile. Short achaetous anterior abdominal zone present. Posterior capillary chaetae present. Posterior glandular pad present.