Scopalina carmela, Turner & Lonhart, 2023

Turner, Thomas L. & Lonhart, Steve I., 2023, The Sponges of the Carmel Pinnacles Marine Protected Area, Zootaxa 5318 (2), pp. 151-194 : 182-184

Scopalina carmela sp. nov.

Figures 21 & 22

Material examined. CASIZ236662 / IZC 00048468 (holotype) and SBMNH700917 (paratype), Inner Carmel Pinnacle (36.55910, -121.96630), 10–18 m, 8/10/2021 .

Etymology. Named for Carmel Bay.

Morphology. Encrusting, 4–6 mm thick. Light orange alive, beige when preserved. Surface is covered in abundant conules, oscula, and large pores.

Skeleton. Nodes of spongin arise from a basal spongin plate and terminate in surface conules. Vertical spongin nodes are occasionally bridged by secondary horizontal branches of spongin. Primary and secondary spongin tracts are cored by styles, either entirely enclosed by spongin or with heads embedded and points emerging; styles are chaotically arranged but generally at an angle between vertical and 45 degrees, tips up. Styles are more abundant near the sponge surface, where they form bouquets at the top of primary spongin tracts, piercing the surface at conules. Sponge also contains meandering, vermiform tracts of spongin that are not cored with styles. Sponge contains abundant sand, but no debris was seen coring spongin tracts. Tracts are often filled and/or coated with what appear to be red algal cells.

Spicules. Long smooth styles that taper gradually to a sharp point; sometimes with subtle step-changes in size near the tip ("telescoping tips"). Holotype 713–915–1132 x 8–13–16 μm (n=26), other sample: 606–809–1017 x 10–16–21 μm (n=20).

Distribution and habitat. Known only from the Carmel Pinnacles.

Remarks. This species is clearly within the Scopalina based on both morphology and genotype. Four species of Scopalina are known from this region, all recently described from Southern California ( Turner 2021). The skeleton and general appearance of this new species is very similar to S. nausicae , but it is easily differentiated from that species by having spicules nearly twice as long ( S. carmela sp. nov. mean length = 869, S. nausicae mean length = 494), and also by its orange color ( S. nausicae is peach-colored). Several pieces of evidence support a hypothesis that S. carmela sp. nov. is a distinct species, and not a northern form of S. nausicae . First, the morphological differences (color and differences in spicule length) are very similar to the differences between S. kuyamu and S. goletensis , which both occur in Southern California. Second, genetic differentiation between S. carmela sp. nov. and S. nausicae are of a similar magnitude as the differentiation between S. kuyamu and S. goletensis at both cox1 and 28S. Third, the final California species of Scopalina , S. jali , is found at both the Carmel Pinnacles and in Southern California, without genetic differentiation at 28S (figure 21).

Close examination or high-resolution photos make this species identifiable in the field: the highly conulose surface, abundant pores and oscules, and light orange color serve to distinguish this species from other California species. Other encrusting orange sponges in California are firm, while this species is very soft and compressible.

Figures

FIGURE 21. Maximum likelihood phylogenies for the Scopalinida. A: 28S locus, B: cox1 locus. Genbank accession numbers are shown; bold indicates new sequences. Node confidence is based on bootstrapping. Scale bar indicates substitutions per site.

FIGURE 22. Scopalina carmela. Field photos of holotype (A) and unsampled individual (B). C: cross-section showing spongin plate and vertical nodes, with associated spicules from holotype. D: Cross-section showing vermiform tracts of spongin, from holotype. E: style from SBMNH700917.