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).