Latrunculia (Uniannulata) velera Lehnert, Stone & Heimler 2006, subgen. nov.

Latrunculia (Uniannulata) velera Lehnert, Stone & Heimler, 2006 subgen. nov., comb. nov.

(Fig. 2 B, 9, 16AH; Tables 8, 9)

Latrunculia velera Lehnert, Stone & Heimler, 2006: 27 –30; Fig. 15 A–F, 16A–D. Latrunculia velera, Abbas et al. 2011: 2429 ‒2430; Fig. 8 D; Stone et al. 2011: 114, Fig. 1–3; 141; 145; 185, Fig. A, B; 186, Fig. C–F; 187, Fig. G–J.

Material Examined. None.

Distribution. Central Aleutian Islands.

Description. Club-shaped to sub-globose sponge with a flattened, circular to kidney-shaped apex (Fig. 9 A, C), about 12 cm diameter, restricted base about 1–2 cm diameter. Slightly elevated cylindrical oscules regularly dispersed across a flat apex, areolate pore fields not visible, possibly positioned laterally. Surface smooth between the oscules, interior cavernous, markedly fibrous, wrinkled in the preserved condition (Fig. B), Overall texture leathery, slightly elastic, and easily torn. Colour in life dull brown, choanosome slightly darker.

Skeleton. Ectosomal skeleton, a detachable, paratangential layer of megascleres upon which sits a singlelayered palisade of anisodiscorhabds. Choanosomal skeleton, a wispy reticulation of megascleres in tracts (modified from Lehnert et al. 2006 and Stone et al. 2011).

Spicules. Megascleres (Fig. 9 D), styles with lightly spined heads very lightly and irregularly spined distal ends (Fig. 9 E), 500–540 × 9–11 µm.

Microscleres (Fig. 9 F), anisodiscorhabds, manubrium, a single stump with denticulate margins, in the same line as the shaft. Basal whorl a ring of thick sculpted spines with rows of tiny teeth that curve along the edges of the sculpted sections, spines orientated obliquely towards manubrium. Median whorl a regular, thick ‘saucer’ with incised, sharply denticulate margins, located approximately centrally along the axis. Undifferentiated subsidiary/ apical whorl arises obliquely from the shaft, from just above the median whorl, forming a thick-walled, concave chalice with finely notched, beaded, denticulate margins. The apex sits atop the slightly concave subsidiary/apical cup and ranges in shape from a lemon-squeezer with five prominent beaded, denticulate ridges extending from the tip to the base, to an opening flower bud, with the tips of the five enfolded spines expanded out (Fig. 9 F, I), 37–43 µm long.

Substrate, depth range and ecology. Locally common in the central Aleutians region where it is found attached to bedrock, boulders and cobbles between 412 and 1009 m, but relatively rare at depths shallower than 600 m.

Remarks. The anisodiscorhabds of L. (U.) velera are similar in general form to those of L. (U.) oparinae, with the undifferentiated subsidiary and apical whorls, and the clearly differentiated manubrium and basal whorl. However, the anisodiscorhabds in each species differ markedly in the degree of micro-ornamentation; in L. (U.) velera the anisodiscorhabds are very smooth with beaded denticulate margins in the apical region, while in L. (U.)

oparinae all features are microspined. The megascleres of L. (U.) velera (500–540 µm) are also considerably larger than those of L. (L.) hamanni sp. nov. (433–508 µm) and L. (U.) oparinae (400–464 µm), but similar in length to those of L. (B.) lincfreesei sp. nov. (480–590 µm). The latter species, however, has been recorded much further east, in the Gulf of Alaska. While L. (U.) velera occurs in the same general area as L. (L.) hamanni sp. nov. and L. (U.) oparinae, it occurs at depths well beyond these two species, from about 400–1000 m.