Haliclona (Soestella) spuma, 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 : 20-22

Haliclona (Soestella) spuma sp. nov.

( Fig. 9 ; Table 2 & Table 3)

Material examined. Holotype — MCCDRS9446, Gordon Rocks , Santa Cruz Island, 0.567° S, 90.142° W, 27 m, 22 Jan 2003 . Paratypes — MCCDRS9447, Gordon Rock , 0.567° S, 90.685° W, 24 m, 20 Jul 2003 ; MCCDRS9448, Guy Fawkes Island , 0.515° S, 90.527° W, 26 m, 26 Jul 2003 . Other material— MCCDRS9449, Rabida Island , 0.406° S, 90.713° W, 17 m, 18 Nov 2003 ; MCCDRS9450, Pinzón Island , 0.592° S, 90.684° W, 14 m, 20 Jan 2003; MC- CDRS9442 , Pinzón Island , 0.619° S, 90.685° W, 24 m, 22 June 2001 .

Type locality. Gordon Rocks , Santa Cruz Island ; 27 m.

Habitat and distribution. Collected from Gordon Rocks, Guy Fawkes Island, Rabida Island, Maria Elena Islet (Pinzón Island); 17–27 m. Found growing on rock. The sponge was also very commonly observed on numerous other islands in the Galápagos Archipelago .

Description. Thinly to thickly encrusting, cavernous sponge, 5–20 mm thick with a lumpy, ridged surface upon which the oscules are located. The surface of the sponge is densely punctate and numerous single and multiple oscules, ≤ 3 mm in diameter, are present that are typically slightly raised on volcano-shaped mounds. Colour in life white to cream, colour in ethanol tan ( Fig. 9A–B ). Texture very soft, friable.

Skeleton. Choanosome is a loose subanisotropic reticulation of small oxeas that form rounded meshes around frequent choanosomal spaces resulting in the cavernous appearance of the sponge and punctate surface. Reasonably robust, irregular multispicular primary tracts are visible forming sculpted or rounded meshes ( Fig. 9C–D ) due to an abundance of loose oxeas that form webs where the ill-defined pauci- to multispicular secondary tracts connect to the primary tracts. Ectosome is loosely tangential with numerous rounded open spaces; there is no special ectosome ( Fig. 9E ). Spongin is scarce.

Spicules. ( Table 3) Megascleres— small, slightly curved oxeas with pointed tips, 164 (136–192) × 8 (5–13) µm (n = 90) ( Fig. 9F ).

Etymology. Named after the white foamy appearance of the sponge surface in life (Latin nominative singular in apposition = ‘foam’).

Remarks. Only one species of Haliclona (Soestella) has been described from the tropical/subtropical eastern Pacific. Haliclona (S.) caerulea ( Hechtel, 1965) from the Pacific side of Panama, Caribbean and Venezuela possesses microscleres in addition to oxeas. The six species of Haliclona (subgenus unknown) from the eastern Pacific, as described for H. (H.) clairae sp. nov. above, are all differ from this species, as outlined in Table 2.

Figures

FIGURE 9. Haliclona (Soestella) spuma sp. nov. A. Holotype, MCCDRS9446, in situ. B. Close up of paratype, MCCDRS9447 showing the punctate surface of the sponge. C. Cross section of the choanosome showing the ill-defined primary tracts (arrows) and the large, rounded choanosomal spaces. D. Higher magnification showing the multispicular primary tracts (black arrow) and the unispicular secondary tracts (white arrow). E. Sponge surface showing irregular tangential ectosome with large spaces. F. Oxeas (all section and spicule images from the holotype).