Vitreotubus digeronimoi Zibrowius, 1979

Vitreotubus digeronimoi Zibrowius, 1979 View in CoL

Figs. 14A–C View Figure 14 , 15A–E View Figure 15

Vitreotubus digeronimoi Zibrowius, 1979: 184 View in CoL , figs 1–2.

Vitreotubus digeronimoi View in CoL – ten Hove 1994:113 ( Seychelles,

empty tubes only); Vinn, 2005: 262–262, fig. 5 (tube ultrastructure); ten Hove & Kupriyanova, 2009: 103–104, fig. 50 (SEM of chaetae).

Material examined: W.54402, Cocos (Keeling) Islands Territory , Muirfield Seamount (13°10'28"S, 96°14'14"E), depth 528 m, 21/10/2022 (1 tube); W.54409 (LK295) GoogleMaps , Cocos (Keeling) Islands Territory , Muirfield Seamount (13°10'28"S, 96°14'14"E), depth 528 m, 21/10/2022 (1 spec); W.55301 (LK317), same locality (1 spec. prepared for SEM) GoogleMaps .

Species diagnosis. Tube entirely vitreous ( Fig. 14A, C View Figure 14 ), more or less quadrangular in cross-section, by its two large undulating ( Fig. 14C View Figure 14 ) or distinctly denticulate lateral keels ( Fig. 14C View Figure 14 ), and with a median keel made of a row of short teeth. Operculum inverse conical with chitinous diabolo-like endplate ( Fig. 14B View Figure 14 , 15A View Figure 15 ). Seven thoracic chaetigerous segments. Collar trilobed. ( Fig. 14B View Figure 14 , 15A View Figure 15 ). Apomatus chaetae absent ( Fig. 15B View Figure 15 ). Thoracic uncini saw-shaped with 6–7 teeth above pointed fang ( Fig. 15C View Figure 15 ). Abdominal chaetae true trumpet-shaped, with two rows of pointed teeth bordering hollow groove and extended into a long lateral spine ( Fig. 15D View Figure 15 ). Abdominal uncini saw-shaped with about 6 teeth anteriorly ( Fig. 15E View Figure 15 ).

Remarks. The species has a very characteristically shaped transparent tube. Not surprisingly, the irregular spherulitic prismatic tube ultrastructure of Vitreotubus closely resembles that of Placostegus tridentatus , a species with similarly transparent tube ( Vinn, 2005).

Zibrowius (1979) designated the station 229/ 9.11.1971 of RV “ Jean Charcot ” Campagne Biaçores collected NW of Santa Maria , Azores (37°01.5'N, 25°14'W, 600 m) as the type locality of V. digeronimoi , but his additional material came from Northern (off Kuria Muria Islands off Oman coast) and Southern ( Mayotte) Indian Ocean localities. The depth range reported for the species is 500–1415 m. Here we provide a new record from Southern Indian Ocean (Muirfield Seamount) of this poorly known, but apparently widely distributed bathyal species and, more importantly, we provide the first DNA sequence data for this species GoogleMaps .

Distribution. Central Atlantic and Indian Ocean; bathyal (500–1415 m).