Cacospongia hermanorum, Sim-Smith & Hickman & Kelly, 2021

Sim-Smith, Carina, Hickman, Cleveland & Kelly, Michelle, 2021, New shallow-water sponges (Porifera) from the Galápagos Islands, Zootaxa 5012 (1), pp. 1-71 : 9-11

Cacospongia hermanorum sp. nov.

( Fig. 4 )

Material examined. Holotype — MCCDRS9434, Los Hermanos Islands , 0.867° S, 90.782° W, 6 m, 3 Feb 2004.

Type locality. Los Hermanos Islands .

Habitat and distribution. Only known from the type locality.

Description. A flattened, cushion-shaped sponge, 50 mm long × 40 mm wide × 15 mm thick ( Fig. 4A, C ). Surface is finely conulose, with conules around 1 mm high. The conules are formed by collagen fibrils that protrude beyond the surface of the sponge, coming together to form the apex of the conules ( Fig. 4B ). A few small, inconspicuous oscules, 1–2 mm in diameter, are present on the upper surface of the sponge. The surface is densely punctate below the surface reticulation of fibres. Texture is very firm and harsh, easily torn. Colour in life and ethanol is blackish brown, interior is tan.

Skeleton. The skeleton is a well-developed, irregular reticulation of concentrically laminated, yellow-brown fibres that are slightly fasciculated just below the surface ( Fig. 4D, F ). Primary fibres are lightly cored with foreign spicules ( Fig. 4E ); 70–140 µm in diameter and separated by a distance of 400–1300 µm. Secondary fibres are uncored, 30–100 µm in diameter. They typically form polygonal meshes that are 80–700 µm in size. Foreign spicules are lightly scattered throughout the choanosome, being more common at the surface of the sponge.

Etymology. Named for the type locality, Los Hermanos Islands in the Galápagos Archipelago.

Remarks. Desqueyroux-Faúndez and Van Soest (1997) described two species of Cacospongia from the Galápagos Islands, C. similis Thiele 1905 and C. incognita Desqueyroux-Faúndez and Van Soest, 1997 , both of which have subsequently been transferred to the genus Scalarispongia due to their regular, ladder-like reticulation of fibres. Scalarispongia similis ( Thiele 1905) also has much thinner primary (40–70 µm) and secondary (30–40 µm) fibres than C. hermanorum sp. nov. Scalarispongia incognita has similar sized primary (120–150 µm) and secondary fibres (50–100 µm) to C. hermanorum sp. nov., but S. incognita has a thick organic, heavily pigmented ectosomal membrane, and a creamy white interior.

Subclass Heteroscleromorpha Cárdenas, Pérez & Boury-Esnault

Order Haplosclerida Topsent

Figures

FIGURE 4. Cacospongia hermanorum sp. nov., holotype, MCCDRS9434: A. Holotype, deck photo. B. Close up of the surface of the holotype, deck photo. C. Cut side view of the holotype, preserved. D. Vertical cross section showing the fibres that protrude through the surface of the sponge and the well-developed fibre reticulation. E. A primary fibre cored with foreign spicules (white arrow) and uncored secondary fibres (black arrow). F. Cross section of a fibre showing the concentric laminations.