Vetulina, SCHMIDT, 1879

GENUS VETULINA SCHMIDT, 1879 View in CoL

Vetulina Schmidt, 1879: 19 View in CoL .

Vetulina View in CoL — Sollas, 1885: 486; Sollas, 1888: 354; de Laubenfels, 1955: E63; Van Soest & Stentoft, 1988: 71; Gruber, 1993: 49, pl. 14: 4–8.

Type species: Vetulina stalactites Schmidt, 1879 (by monotypy).

Emended diagnosis: Polymorphic lithistid Demospongiae: encrusting to hemispherical, lamellate or vase shaped; acrepid polyaxial desmas (sphaeroclone to astroclone) as megascleres; microscleres if present are styles, (sub)tylostyles and strongyles (modified from Pisera et al., 2017).

Remarks: Only lamellate or vase-shaped growth forms are published in the diagnosis of the genus ( Pisera & Lévi, 2002b; Pisera et al., 2017). However, in the present study we describe two new species, the first with a thick encrusting, spreading morphology, and the second forming a thick hemispherical encrustation with a spherical outline, requiring amendment to the diagnosis of the genus. In addition, (sub)tylostyles and strongyles of various sizes (75–125 µm) are discovered and considered here as microstyles, despite their size, following the same argument as Pisera et al. (2017), who considered the location/function of these styles in the skeleton as being microscleres.

VETULINA STALACTITES SCHMIDT, 1879 View in CoL

( FIGS 2A–F, 3A–F)

Vetulina stalactites Schmidt, 1879: 19 View in CoL , pl.1: 1, pl. 2: 9.

Vetulina stalactites View in CoL — Sollas, 1885: 486: pls 3, 4; Sollas, 1888: 454. von Lendenfeld, 1903: 150; de Laubenfels, 1955: E63, fig. 46: 4; Van Soest & Stentoft, 1988: 71, text-fig. P.43; Gruber, 1993: 49, pl. 14: 4–8; McInerney et al., 1999: p. 346.

Vetulina sp. ,— Redmond et al., 2013: p. 400.

Material examined: HBOM 003 View Materials :01011 ( HBOI 21 -V-00-1-004): Johnson Sea-Link II (JSL-II) dive 3226, South Central Coast , off Piscadera Bay, Curaçao, 12°6′38.77″N, 68°58′43.25″W, 212 m, May 2000 GoogleMaps . HBOI 11 -V-00-3-006: JSL-II dive 3210, South Central Coast , Seamount off Porto Mari Bay, Curaçao, 12°12′51.19″N, 69°5′50.21″W, 180 m, May 2000 GoogleMaps . HBOI 11 -V-00-3-004: JSL-II dive 3210, South Central Coast , Seamount off Porto Mari Bay, Curaçao, 12°12′51.19″N, 69°5′50.21″W, 219 m, May 2000 GoogleMaps . HBOI 31 -VIII-93-4-004: JSL-I dive 3601, North Coast , 4 Nautical miles ( NM) SE of Galina Port, Jamaica, 18.355°N, 76.833°W, 350 m, August 1993 GoogleMaps . HBOI 14 -V-00-1-007: JSL-II dive 3214, West Coast , Wecua Port, Bonaire, 12°13′20.35″N, 68°25′2.93″W, 256 m, May 2000 GoogleMaps . HBOI 13 -XI-98-3- 003: JSL-I dive 4098, Andros Island , East of Stafford Creek, Bahamas, 24°54′49.79″N, 77°52′12.61″W, 498 m, June 1998 GoogleMaps .

Ty p e l o c a l i t y: E a s t e r n C a r i b b e a n, B a r b a d o s (13°10′0″N, 59°40′0″W), 183–329 m, RV Hassler Expedition ( Fig. 1A) .

Distribution: Barbados (13°10′0″N, 59°40′0″W), 135–601 m ( Schmidt, 1879); Curaçao, 12°6′– 12°12′N, 68°58′– 69°05′W, 137–219 m (present study); Jamaica, 18°21′18.07″N, 76°49′59.41″W, 350 m (present study); Turks and Caicos, 21°31′– 21°52′N, 71°8′– 72°20′W, 520–550 m (present study); Bahamas, 23°38′– 24°54′N, 74°56′– 77°52′W, 498–569 m (present study); St Vincent Island, 13°9′38.99″N, 61°16′31.19″W, 247 m (present study); Bonaire, 12°13′20.35″N, 68°25′2.93″W, 256 m (present study); Martinique 14°30′18″N, 61°6′12″W, 220 m ( Pomponi et al., 2001).

Description: The gross morphology is irregularly lamellate to undulating and foliose, occasionally with tubular outgrowth ( Fig. 2A–E) or cup to vase shaped ( Fig. 2F); the base is attached to hard substratum. Dimensions of the cups are ~ 5–20 cm in diameter and ~ 7–26 cm high, with walls of 0.6–1 cm thickness and round, flattened margins. Outer surfaces contain well-developed, regularly concentric growth lines ( Fig. 2A–F) and irregularly distributed pores of ~ 0.1 mm in diameter ( Fig. 3A, B), while the inner surface is rather smooth and finely porous ( Fig. 2E). Texture stony. Colour in life is pale yellow, yellowish brown to tan in ethanol.

The skeleton is composed of a dense and regular network of sphaeroclone desmas ( Fig. 3D–F) stacked upon one another ( Fig. 3D).

Megascleres are sphaeroclone desmas, 100–350 µm in diameter, with an irregularly globular centrum, 0.03–0.06 mm in diameter, with spinose root-like outgrowths emanating from the top of each desma ( Fig. 3E). Immature desmas have a hollow centre (hole: ~20–25 µm in diameter; Fig. 3E, F). Three to eight sparsely spinose rays branch from the lower part of the centre ( Fig. 3E). Zygomes of the branching rays attach the upper centre part of adjacent desmas to build up the skeleton. The globose centre aligns to the surface, with rays branching and extending towards the choanosome ( Fig. 3A–C).

Microscleres are microstyles ~50–150 µm long and 4 µm thick, with mucronate pointed tips ( Fig. 3C). Microstyles exclusively protrude from the ectosome surface and are sparsely distributed around some ostia ( Fig. 3C).

DNA barcodes: In the present study, we sequenced partial cox1 (‘Folmer’ fragment) of specimens: HBOI 19-XI-94-1-012, 2-VII-89-2-012, 21-V-00- 1-004, 31-VIII-4-004, 12-XI-94-3-005, 14-V-00-1- 007, 14-XI-02-3-001, 13-XI-98-3-003, 11-V-003-004, 11-V-00-3-008, 11-V-00-3-006, 31-III-89-1-003 and 14-V-00-1-009. All 13 sequences are identical in all specimens; partial 28S fragment C1–D2 for HBOI 31-VIII-93-4-004, 13-XI-98-3-003, 11-V-00-3-006, 21-V-00-1-004 and 14-V-00-1-007, all of which are identical; ITS for HBOI 11-V-00-3-006, 21-V-00-1- 004, 31-VIII-93-4-004, 13-XI-98-3-003 and 11-V-00- 3-004, all of which are identical; and partial 18S for HBOI 14-XI-02-3-006, 13-X-03-3-003 and 13-XI-98-3-003, all of which show identical sequences. Additionally, GenBank accession no. KC901963 View Materials ( Redmond et al., 2013) and AJ224648 View Materials ( McInerney, Adams & Kelly, 1999) (18S) are added, whereupon sequence AJ224648 View Materials has ambiguous characters towards the 3′ end.

Remarks: Before this study, V. stalactites was reported only from the type locality of Barbados, between 153 and 601 m ( Schmidt, 1879; Van Soest & Stentoft, 1988) and Martinique (229 m; Pomponi et al. 2001). Here, we expand the distribution of this species in the Tropical Western Atlantic to the Bahamas, Turks and Caicos Islands, Jamaica, Curaçao, St Vincent and Bonaire, all collected between depths of 137 and 569 m (see Fig. 1). Our re-examination of V. stalactites , in particular the detailed observation of the ectosomal membrane, clearly produces evidence of the presence of microscleres (styles) throughout the species ( Fig. 3C), which were already noticed by Sollas (1888), but considered by Pisera & Lévi (2002b) to be contamination. Finally, spinose microxeas, as observed from the inner surface of the syntype MCZ 6640 by Pisera & Lévi (2002b), could not be detected in any of our examined specimens.