Taxonomy of Serpulidae (Annelida, Polychaeta): The state of affairs Author Ten Hove, Harry A. Author Kupriyanova, Elena K. text Zootaxa 2009 2009-03-16 2036 1 126 journal article 1175­5334 15888B41-A000-4611-BEC8-F9359D1149CD 20. Marifugia Absolon & Hrab ĕ, 1930 ( Fig. 27 ) Type-species : Marifugia cavatica Absolon & Hrabĕ, 1930 Number of species: 1 Tube white, opaque, circular in cross-section; irregular longitudinal keel and collar like rings may be present. Thin hyaline granular overlay of the tube present. Operculum fig-shaped to inverse conical, with (or without) chitinous endplate. Peduncle flattened cylindrical, smooth, without distal wings, gradually merging into opercular ampulla; inserted just below and between first and second dorsal radiole on left side (in large specimen almost covering base of branchial lobe). Pseudoperculum absent. Radioles arranged in semi-circles, up to 6 per lobe. Inter-radiolar membrane, branchial eyes and stylodes absent. Mouth palps not found. 6 thoracic chaetigerous segments. Collar non-lobed but with low medio-ventral projection. Thoracic membranes narrow but forming apron. Tonguelets absent. Collar chaetae absent. Thoracic chaetae limbate, Apomatus chaetae absent ( Fig. 27A ). Thoracic uncini saw-to-rasp-shaped, with about 8 teeth in profile, up to 4 in a row above blunt almost square shallowly gouged anterior peg (dental formula P:4:3:2:1:1:1:1:1, Fig. 27B ). Triangular depression absent. Abdominal chaetae trumpet-shaped, long, smoothly bent, with hollow tip bordered with pointed teeth ( Fig. 27D ). Posterior abdominal capillaries not observed. Uncini saw-to-rasp- shaped; anterior peg simple rounded ( Fig. 27C ). Achaetous anterior abdominal zone, long posterior capillary chaetae and glandular pad absent. FIGURE 26. SEM micrographs of chaetae in Laminatubus alvini . Galapagos rift, “ Alvin ” dive 884, Garden of Eden, hydrothermal vent areas, 0°47.69' N, 80°07.74' W, 2482 m, ZMA V.Pol. 3480. A—details of Spirobranchus collar chaeta, B—uncini of 4 th thoracic chaetiger, C—anterior abdominal uncini, D—anterior abdominal chaetae, details of hollow tip. Remarks. Marifugia cavatica is unique in being the world's only fresh-water serpulid, of presumably marine origin ( Sket 1983 ), inhabiting subterranean waters of the Dinaric karst of the former Yugoslavia . The most recent study (Kupriyanova et al. , in prep.) summarises data on ecology, distribution, and reproduction of the species and shows its close relationship with Ficopomatus . Marifugia cavatica Absolon & Hrabĕ, 1930 , Bosnia and Herzegovina , Croatia , Slovenia to extreme N.E. Italy ; fresh-water subterranean caves.