Latrunculia velera, Lehnert, Helmut, Stone, Robert & Heimler, Wolfgang, 2006

Lehnert, Helmut, Stone, Robert & Heimler, Wolfgang, 2006, New species of deep­sea demosponges (Porifera) from the Aleutian Islands (Alaska, USA), Zootaxa 1250, pp. 1-35 : 27-28

Latrunculia velera sp. nov.

(Fig. 15 a–f, Fig. 16 a–d) Description

Dark brown, subglobose sponge (Fig. 15 a) with a smooth, uneven surface. The surface is leathery, only slightly elastic, easily broken. There are small circular, slightly elevated oscules scattered over the surface. Areolate pore­fields are not present. The interior is markedly fibrous, somewhat similar to L. oparinae Samaai & Krasokhin, 2002 , but differing slightly in shape and clearly in the absence of areolate pore­fields and the form of the anisodiscorhabds. The holotype was attached near its base to a cobble.

Skeleton: The ectosome is a unispicular layer of discorhabds, all arranged with their longitudinal axis perpendicular to the surface. The choanosome is a reticulation of polyspicular tracts of styles with some anisodiscorhabds in between.

Spicules: Megascleres are styles (Fig. 15 b) with slightly acanthose heads (Fig. 15 c), 500–540 x 9–11 µm. Microscleres are relatively smooth anisodiscorhabds (Fig. 15 e), 37–43 µm. The manubrium is cylindrical, acanthose and followed immediately by the median whorl which consists of cylindrical, spined processes, arranged vertical to the spicule axis (Fig. 15 e, upper right). The subsidiary whorl widens conically on one side and is flat on the other side (Fig. 15 e, center). It is only slightly notched with finely dented margins (Fig. 15 f, view from above). The apical whorl also widens conically towards the apex but forms a flat disc at the base of the apex (Figs. 15 e, f). Its margins are finely dented. The apex (Figs. 15 f, 16 a) narrows to a pointed tip with five prominent dented lines running from the base to the tip.

Discussion

There is only one known species of Latrunculia which shares the styles with acanthose bases: Latrunculia oparinae . Samaai & Krasokhin (2002) who described L. oparinae from the Kuril Islands at depths between 127– 202m. L. velera n.sp was found only at depths below 1000 m and seems to occupy different habitats. Both species have styles and anisodiscorhabds of comparable sizes but, the anisodoscorhabds of L. velera are much smoother and of different geometry.

Distribution

Known only from the type­locality.

Etymology

Named after the RV Velero IV.

Figures

FIGURE 16. Latrunculia velera sp. nov. a, Side view of apex of anisodiscorhabd. b, Early developmental stage of anisodiscorhabd on pointed end of style. Acanthose pointed ends, as shown here are rare. c, Developmental stage of anisodiscorhabd between two fully developped. d, More smooth variation of anisodiscorhabd.