Clathria (Microciona) rumsena, 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 : 164-166

Clathria (Microciona) rumsena sp. nov.

Figures 2 , 8

Material examined. Holotype: CASIZ236652 , Inner Carmel Pinnacle, (36.55852, -121.96820), 10–24 m, 9/22/21; paratype: IZC00048437 , Fire Rock, Pescadero Point, Carmel, (36.55898, -121.95110), 10–22 m, 8/10/22.

Etymology. Named in honor of the Costanoan Rumsen Carmel Tribe, whose ancestral lands include those surrounding Monterey and Carmel bays.

Morphology. Thinly encrusting, 1–2 mm thick; light orange to peach colored alive; fades to beige in ethanol. Surface of holotype bearing evenly-spaced round oscula surrounded by a network of transparent surface channels.

Skeleton. Thick styles with heads embedded in basal spongin plate and nodes of spongin arising from it. Acanthostyles echinating spongin nodes. Thin styles present as dense, upright bouquets at sponge surface.

Spicules. Thick styles, thin straight styles, acanthostyles, palmate isochelae.

Thick styles: curved and tapering; some are weakly subtylote and have weakly spined heads. Holotype had a few capsule or strongyle-shaped spicules that appeared to be aberrant styles with two rounded ends. Holotype 384–744–1095 x 17–29–38 μm (n=35), both samples combined 384–729–1095 x 7–28–38 μm (n=40).

Thin straight styles: straight; some have very weak tyles, but many unadorned. Holotype 158–292–637 x 3–5– 10 μm (n=138), both samples combined 158–287–637 x 3–5–10 μm (n=155).

Acanthostyles: heads densely covered in round bump–like spines; spines on shaft more pointed, curving towards head, most dense near tips. Holotype 121–188–287 x 11–15–20 μm (n=30), both samples combined 112–188–381 x 8–15–27 μm (n=48).

Palmate isochelae: holotype 12–15–17 μm (n=21), both samples combined 12–16–20 μm (n=52).

Distribution and habitat. Known from two samples, both collected on natural rocky reefs offshore of Pescadero Point, Carmel Bay, California.

Remarks. Clathria rumsena is differentiated from all other Clathria in the region by having longer styles of all types (thick styles, thin styles, and acanthostyles). The most similar species is Clathria asodes ( de Laubenfels, 1930) , a thinly encrusting yellow species. In addition to the color difference, the maximum lengths of all C. asodes spicule types —including chelae—are less than the average lengths for C. rumsena ( de Laubenfels 1932; Lee et al. 2007). All other thinly encrusting Clathria in the region have qualitative as well as quantitative differences, such as lacking chelae ( C. pseudonapya ( de Laubenfels, 1930)) or having arcuate chelae ( C. brepha ( de Laubenfels, 1930) , and C. spongigartina ( de Laubenfels, 1930)) . Thickly encrusting Clathria from the region differ in additional ways as well, such as lacking spines on large styles; these species are also genetically differentiated as shown in the phylogenies (figures 2 & 3).

The encrusting morphology and skeletal structure of this species are consistent with assignment to the subgenus Microciona . The subgenus Thalysias was also considered: this subgenus is defined by having two size classes of thin styles, with larger forms subectosomal, supporting brushes of small styles in the ectosome ( Hooper 2002b). The thin styles of C. rumsena are found in a large size range, but have a continuous distribution with a single mode, and no evidence of a multi-layered ectosomal skeleton could be found.

Clathria rumsena sp. nov. cannot be identified in the field. In addition to the sympatric species of Clathria , several species of thinly encrusting Antho occur in the same habitats. Some average differences in color, patterning, and texture have been noted in specific locations, but overall, variability frustrates attempts to identify thinly encrusting red/orange sponges in the field in California.

Figures

FIGURE 2. Maximum likelihood phylogeny of the 28S locus for the Poecilosclerida. Genbank accession numbers are shown; bold indicates new sequences. Node confidence is based on bootstrapping. Scale bar indicates substitutions per site. Colors indicate clades containing new taxa, as referenced in the text.

FIGURE 8. Clathria rumsena. Field photo of holotype (A) and IZC00048437 (B). C: Cross section. D: Thick style. E: Thin style. F: Acanthostyles. G: Chelae. C–G from holotype.