Scopalina nausicae, 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 : 362-364

Scopalina nausicae sp. nov.

( Fig. 3 )

Material examined. Holotype: ( CASIZ 235474 ) Point Loma , San Diego, California, USA (32.69438, -117.26860), 15 m depth, 2/7/20 . Paratypes: ( CASIZ 235471 ) Coal Oil Point , Santa Barbara, California, USA (34.40450, - 119.87890), 11 m depth , 8/30/19; ( CASIZ 235472 ) Isla Vista Reef , Santa Barbara, California, USA (34.40278, - 119.85755), 12 m depth , 8/1/19; ( CASIZ 235473 ) Arroyo Quemado Reef , Santa Barbara, California, USA (34.46775, -120.11905), 11 m depth , 1/7/20.

Etymology. Named for the fictional character Nausicaä from the film Nausicaä and the Valley of the Wind.

Morphology. Encrusting, 2–4 mm thick, up to 10 cm across ( Fig. 3 ). Soft and compressible. Prominent conules 0.5–1.0 mm in height, 1.5–3.5 mm apart; spicules protrude at conules, making them microscopically hispid. Scattered oscules 1–2 mm in diameter. In nature, ectosome appears opaque at conules but often lacy and porous between them; ectosome more opaque in collected samples. Ectosome peach colored, choanosome yellow when alive; all tissues fade to beige when preserved in ethanol.

Skeleton. Vertical trunks of spongin, 100–550 μm wide, arise from a basal spongin mat and terminate in surface conules. Secondary branches of spongin 50–100 μm wide arise from primary trunks, branching off at an angle of less than 90 degrees and still extending towards surface. Primary and secondary trunks cored with spicules with pointed ends up; spicules entirely enclosed in spongin or with tips projecting; projecting tips fan out to create a bouquet that pierces the ectosome at conules. An additional type of spongin tract is distinct from those described above: 60–90 μm wide, these tracts branch from primary trunks at approximately 90-degree angles, then meander through the choanosome in a vermiform fashion, sometimes branching; these vermiform tracts do not contain spicules. Basal spongin, spicule-containing spongin trunks, and vermiform tracts are sporadically cored with sediment. Spiculecontaining and vermiform spongin tracts are often filled and/or coated with what appear to be algal cells; these are red in preserved tissue.

Spicules. Styles only, usually bent towards the head end, thickest at the head and tapered to a point. Some show “telescoping” (width decreasing in a step-wise fashion) at the pointed end. Average spicule length for each voucher: 454, 483, 505, 532 μm (N=31–40 per sample); total range in spicule length across vouchers 375–623 μm (N=135). Average spicule width at head, for each voucher: 9, 9, 11, 11 μm (N=31–40 per sample); total range in spicule width at head 5–17 μm (N=135).

Distribution and habitat. This species is common on the shallow (5–16 m) rocky reef at Coal Oil Point, Santa Barbara, California. Often found on vertical rock walls or boulders, it can also occur on flatter areas, and has been found partially buried by sand. It was not found at most other locations investigated, but was located in similar habitat at the Arroyo Quemado Reef (near Point Conception) and in the kelp forests in extreme Southern California, off Point Loma and La Jolla, San Diego. It is therefore likely that the specie’s range encompasses at least the Southern Californian and Ensenadan biogeographical provinces, bounded by Point Conception in the North and Punta Eugenia in the South ( Blanchette et al. 2008; Valentine 1966).

Remarks. Skeletal architecture, spiculation, and genotype all conspire to place this species within the Scopalina . I was unable to detect the “graininess” said to characterize other Scopalinidae . However, this was hard to assess due to the abundant sediment within the sponge: dark grains were apparent, but appeared to be sediment rather than refractile cells.

Spicule dimensions, skeletal morphology, and genotype all serve to differentiate S. nausicae sp. nov. from the three other species newly described here. Fourteen other species are currently placed in the genus Scopalina , according to the World Porifera Database ( van Soest et al. 2019). None of these are known from the Eastern Pacific, making them unlikely conspecifics with any of the species described here. The gross morphology of S. nausicae sp. nov. in the field is quite similar to published images of S. ruetzleri ( Wiedenmayer, 1977) (West Atlantic) and S. erubescens ( Goodwin et al., 2011) (Faulkland Islands) . Spicule length and sponge color also match S. erubescens better than other Scopalina , making this species the most likely conspecific. In addition to geographic separation, however, S. erubescens is larger, more thickly encrusting, and has thicker spicules and spicule bundles. The description of S. erubescens also lacks any mention of the vermiform spongin tracts that pervade S. nausicae sp. nov. ( Goodwin et al. 2011). Scopalina ruetzleri can be excluded as a conspecific based on genetic data at both cox1 and 28S as well as color and habitat ( Rützler et al. 2003). This species is described as ranging throughout the Caribbean, but was also recently reported from the tropical Eastern Pacific ( Carballo et al. 2019). This latter report is not accompanied by morphological or genetic information, so comparisons between tropical Pacific Scopalina and S. nausicae sp. nov. await future investigation.

Within its range, it is likely that this sponge can be identified from field photos, as I have seen no other sponge with a similar morphology to date.

Figures

FIGURE 3. Scopalina nausicae sp. nov. A: Field photo of paratype (CASIZ 235472), Isla Vista Reef. B: Field photo of paratype (CASIZ 235473), Arroyo Quemado Reef. C, D: Skeletal architecture of holotype (CASIZ 235474), Point Loma; scale applied to both. In C, vermiform and primary spongin trunks are coated in apparent algae. In D, only primary spongin trunk showing algae, but vermiform tracts are sporadically cored with sediment. E, F: spicules from paratype (CASIZ 235472).