Bathyditrupa Kupriyanova, 1993b

Ten Hove, Harry A. & Kupriyanova, Elena K., 2009, Taxonomy of Serpulidae (Annelida, Polychaeta): The state of affairs, Zootaxa 2036, pp. 1-126 : 29

2. Bathyditrupa Kupriyanova, 1993b

( Fig. 9)

Type-species: Bathyditrupa hovei Kupriyanova, 1993b

Number of species: 1

Tube free, curved but not coiled, white, opaque, rectangular in cross-section; collar-like rings absent. Granular overlay absent. Operculum inverse conical, with brown chitinous endplate, flat or slightly concave. Opercular ampulla gradually merges (constriction absent) into thick, rather triangular peduncle with pinnules, but without wings. Peduncle inserted as the second dorsal radiole on one side. Pseudoperculum absent. Arrangement of radioles semi-circular, up to 6 per lobe. Branchial eyes not observed. Inter-radiolar membrane and stylodes absent. Mouth palps not observed. 5 thoracic chaetigerous segments. Collar non-lobed, short, with entire edge. Tonguelets absent. Thoracic membranes short, ending at second thoracic segment. Collar chaetae limbate ( Fig. 9A). Apomatus chaetae absent ( Fig. 9B). Thoracic uncini saw-to-rasp-shaped, with up to 4 (?6) teeth in a row above peg, with about 15 curved teeth in a row in profile ( Fig. 9D). Anterior peg bifurcate in high-power microscopy, but clearly gouged when studied by SEM ( Fig. 9E). Thoracic triangular depression absent. Abdominal chaetae all capillary ( Fig. 9C), posterior ones slightly longer; abdominal uncini raspshaped ( Fig. 9F). Achaetous anterior abdominal zone short, just one or two segments. Posterior glandular pad absent.

Remarks. This abyssal species had only been reported from the Kurile-Kamchatka trench ( Kupriyanova 1993b). We studied 2 additional specimens from the North Pacific Ocean, collected by the R/V Vityaz, Sta. 3151, near the Emperor Seamounts, 44°28'3'' N 170°07'0''E, grab, 5237 m, ZMA V.Pol. 5326; Sta. 4370, NE off Hawaii, 26°04'2'' N, 153°49'3'' W, grab, 6050 m, ZMA V.Pol. 5325. The characteristic feature of the genus is a free, unattached tube similar to that of Ditrupa , but rectangular in cross-section and without an outer hyaline layer (see The tube, p. 7). It is probably synonymous with Nogrobs fide Jäger (2004: 140) , see remarks below (p. 69).

Bathyditrupa hovei Kupriyanova, 1993b , Kurile-Kamchatka trench and North Pacific Ocean; abyssal.