Scopalina kuyamu, Turner, 2021

Turner, Thomas L., 2021, Four new Scopalina from Southern California: the first Scopalinida (Porifera Demospongiae) from the temperate Eastern Pacific, Zootaxa 4970 (2), pp. 353-371 : 364

Scopalina kuyamu sp. nov.

( Fig. 4 )

Material examined. Holotype: ( CASIZ 235469 ) Naples Reef , Santa Barbara, California, USA (34.42212, - 119.95154), 12 m depth, 7/31/19.

Etymology. Named for the village of Kuyamu, a community of Barbareño Chumash that once stood onshore at the site where the sponge was discovered.

Morphology. Encrusting, 1–2 mm thick, 6 cm across ( Fig. 4 ). Soft and compressible. Surface hispid due to a profusion of protruding styles. Distinct ectosome not apparent. Peach colored in nature, except for translucent-white varicose channels running along surface. Few scattered oscules, each ~300 μm diameter; smaller pores (approxi- mately 80 μm diameter) abundant and uniformly distributed. Beige when preserved in ethanol.

Skeleton. Basal mat of spongin cored with sediment. Extensions of spongin arise from this mat: most are low mounds, some only 25–50 μm high, but some are fingers 100–300 μm high and cored with sediment. Heads of spic- ules are embedded in these mounds and fingers, either singly or in bundles of up to 12. Spicules extent vertically and pierce the surface of the sponge.

Spicules. Styles only, usually bent towards the head end, thickest at the head and tapered to a point. Some spicule tips are “telescoping” (width decreasing in a step-wise fashion) at the pointed end. Spicules averaged 1557 μm in length (N=35, range 879–1948 μm); 16 μm in width (N=35, range 11–21).

Distribution and habitat. Only a single individual has been found, on a vertical wall at 12 m depth, at Naples Reef, in Santa Barbara, California. Habitat was rocky reef with abundant bryozoan, sponge, and anthozoan cover, adjacent to year-round kelp forest. Three additional dives at the same location failed to locate other individuals; similar, nearby habitat to the East and West also had considerable search effort, so this species appears to be rare in this area.

Remarks. This sponge is quite genetically and morphologically distinct from S. nausicae and S. jali . The spicular architecture is fairly similar to S. goletensis , though the spicule density is lower. As a result, S. goletensis is removable from the substrate as a fairly firm sheet, while S. kuyamu peels away in rubbery strips that curl up upon themselves. Also, the spicules average over twice as long in S. kuyamu , with non-overlapping size ranges among the spicules measured. These morphological differences seem unlikely to be due to environmental influences, as the two species were collected at the same depth, at very similar reefs, less than 5 km apart. Together with the considerable genetic divergence, these differences support species status for both species.

Among Scopalina from other regions, the only species with spicules as large as S. kuyamu are S. lophyropoda ( Schmidt, 1862) ( Blanquer & Uriz 2008) (Mediterranean) and S. bunkeri ( Goodwin et al., 2011) ( Falkland Islands). In addition to great geographic distance, S. lophyropoda can be excluded based on genetic data ( Fig. 1 ); S. bunkeri has a different spicular architecture, gross morphology, and color ( Goodwin et al. 2011).

It does not seem likely that this species can be identified from field photos alone, though it is difficult to say if there are reliable field marks until more individuals are found.

Figures

FIGURE 1. Gene tree at the cox1 mitochondrial locus. Bootstrap values are shown for nodes with> 50% support; nodes with <50% support are collapsed. Genbank accession numbers are shown; those beginning with M, shown in bold, are new. Scale bar indicates substitutions per site. Root placement based on Redmond et al. (2013).

FIGURE 4. Scopalina kuyamu sp. nov.. All images from holotype.A: field photo. B: Skeletal architecture, showing basal plate cored with copious sediment. C, D spicules.