Spiraserpula Regenhardt, 1961

Kupriyanova, Elena K., Sun, Yanan, Ten Hove, Harry A., Wong, Eunice & Rouse, Greg W., 2015, Serpulidae (Annelida) of Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 275-353 : 324

Genus Spiraserpula Regenhardt, 1961

Type-species. Spiraserpula spiraserpula Regenhardt, 1961

Diagnosis. (from ten Hove & Kupriyanova 2009). Tube variable in colour, from white to orange and mustard, or with pink lateral longitudinal stripes; opaque; circular to trapezoidal in cross-section, rarely with small peristomes. Rounded longitudinal keels may be present; hyaline granular overlay present. Tube with internal longitudinal keels or other structures and/or rows of teeth. Operculum soft, funnel shaped, formed of fused radii, endplate absent. Operculum absent in some species. Peduncle smooth, cylindrical, without wings; it is formed from the second dorsal radiole on one side. Pseudoperculum present. Radioles arranged in semi-circles, up to 8 per lobe. Interradiolar membrane present. Branchial eyes may be present. Stylodes absent. Mouth palps absent. Five to ten thoracic chaetigerous segments. Collar trilobed, tonguelets absent. Thoracic membranes ending in mid-thorax. Collar chaetae bayonet-shaped and limbate. Apomatus chaetae absent. Thoracic uncini saw-shaped, with up to 7 teeth above anterior pointed fang. Thoracic triangular depression present. Abdominal chaetae flat trumpet-shaped with denticulate edge. Abdominal uncini similar to thoracic ones, smaller, anteriorly saw-shaped but becoming rasp-shaped towards the pygidium, with up to 8 teeth in profile, up to 7 teeth in a row. Achaetous anterior abdominal zone absent. Posterior capillary chaetae present. Posterior glandular pad absent.

Remarks. The genus was previously known only from fossils. It was revised by Pillai & ten Hove (1994) to include 18 Serpula- like species that lack an apron, but most characteristically possess sharp ridges and spines (“internal tube structures”, ITS) sticking out into the lumen of their tubes. During the first contacts between Pillai, ten Hove, and Zibrowius in the startup of what ended with the revision by Pillai & ten Hove (1994), the three specially searched existing collections for the presence of what possibly might be representatives of what they thought to be a special group of Serpula . This action indeed revealed a fair number of candidates. It is only after that process of increasing awareness that ten Hove, diving in the Caribbean (1987–1992) found new material in almost every dive. Nevertheless, it is a rather cryptic genus, as evidenced too by the fact that after its revision in 1994 hardly any new material has been recorded.