Clathria (Microciona) unoriginalis, 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 : 162-164

Clathria (Microciona) unoriginalis sp. nov.

Figures 2 , 3 , 7

Material examined. Holotype: CASIZ236653 / IZC00048440 , Inner Carmel Pinnacle, (36.55852, -121.96820), 10–24 m, 9/22/21; paratypes: SBMNH700906 , Arroyo Quemado Reef, Santa Barbara, (34.46775, -120.11905), 7–11 m, 1/7/20; IZC00048439 , Cannery Row, Monterey, (36.61798, -121.89780), 9–16 m, 9/21/21; IZC00048438 , 1000 Steps Reef, Santa Barbara, (34.39472, -119.71347), 4–6 m, 7/12/19; SBMNH700912 , Carmel Point, Carmel, (36.54488, -121.93300), intertidal, 2/7/21.

Etymology. Named for its similarity to the sympatric congener, Clathria originalis ( de Laubenfels, 1930) .

Morphology. Thinly encrusting, 1–2 mm thick; bright orange to orange-red in life, fades to beige in ethanol. Surface covered in minute pores; numerous, evenly-spaced round oscula, each 1–2 mm across, present in larger samples; oscula with slightly raised rims, usually surrounded by a vein-like network of subsurface channels.

Skeleton. Columns of spongin cored with large styles; coring styles close to vertical, leading to fairly compact columns, but some styles with tips free and angled out, making columns slightly plumose. Coring spicules at the top of columns flare out into bouquets. Columns chaotically bridged by single, horizontal spicules in spongin, making skeleton ladder-like. Thin styles present as disorganized clumps within bouquets of large spicules at the top of columns. Few chelae seen in sections; all were near ectosome. No toxas seen in sections.

Spicules. Thick styles, thin ectosomal subtylostyles, palmate isochelae, toxas.

Thick styles: gently curved and gradually tapering. Thin (potentially immature) styles in this category are differentiated from thin subtylostyles by the absence of a tyle, more pronounced curvature, and more gradual taper. In one sample (IZC00048438), thick styles were mostly subtylote and some bore minute dimples on head; other samples had few or no styles that were subtylote and no dimpling on heads. Holotype 203–328–525 x 16–22–29 μm (n=53); all samples pooled 135–253–525 x 7–17–29 μm (n=197); lengths quite variable across samples, but variation not partitioned by geographic region; mean values per sponge from 207 to 328 μm.

Thin ectosomal subtylostyles: many subtylote, usually with small spines on heads. Straight or slightly curved. In some samples the thin styles averaged shorter than thick styles, but in other samples this was reversed. Holotype 163–268–452 x 3–5–6 μm (n=21); all samples pooled 133–291–506 x 2–4–6 μm (n=82); mean lengths per sponge from 210 to 325 μm.

Palmate isochelae: holotype 14–19–21 μm (n=15); all samples pooled 13–17–21 μm (n=44).

Toxas: none seen in holotype; common in one sample ( IZC00048438 ); rare in other samples. All samples pooled: 44–113–206 μm (n=26) .

Distribution and habitat. Of the five known samples, two were collected on the Santa Barbara coast (Southern California) and three are from around the Monterey Peninsula (Central California). Intertidal to at least 10 m depth on natural reefs where kelp forest is found.

Remarks. The genus Clathria is well represented in the Northeast Pacific, with 11 previously described species in the region. Only two of these species lack acanthostyles: C. originalis ( de Laubenfels, 1930) and C. pennata ( Lambe, 1895) ; of these, only C. originalis has chelae. Clathria unoriginalis is very similar to C. originalis in terms of morphology, skeletal structure, and spiculation, but these species can be distinguished by the longer styles of C. unoriginalis . The styles of C. originalis were originally described as 150–155 μm in length; a more recent publication lists the thick styles as 130–165 μm and the thin styles as 90–200 μm ( Lee et al. 2007). Preliminary analysis of 13 C. originalis samples collected by the authors finds that the mean values for each sponge vary from 102–155 μm for thick styles and 100–127 μm for thin styles. Though the values for C. unoriginalis are highly variable, all samples average longer than C. originalis : 207–328 μm for thick styles and 210–325 μm for thin styles. These long styles are more similar to C. pennata , which opens the possibility that the presence of chelae is variable in C. pennata . This is refuted by the DNA data, which support species status for all three species (figures 2 & 3). The encrusting morphology and skeletal structure of this species are consistent with assignment to the subgenus Microciona .

The World Porifera Database currently lists an additional Clathria species for the region that lacks acanthostyles: C. hartmani ( Simpson, 1966) . This name is a junior synonym of C. originalis . When de Laubenfels first published descriptions of the encrusting orange sponges of the Monterey Peninsula, he mentioned that some C. pennata have chelae, and said these forms may be a different variety ( de Laubenfels 1927). After additional study, de Laubenfels named the forms with chelae C. originalis ( de Laubenfels 1930, 1932). Simpson (1966) later published the name C. hartmani for the type with chelae, citing the 1927 paper, and apparently not realizing that the name C. originalis had already been applied. As a result, all later authors working in the region correctly considered C. hartmani a junior synonym of C. originalis ( Bakus & Green 1987; Hartman 1975; Lee et al. 2007).

It was noted by de Laubenfels that C. pennata occurs closer to the high tide mark than any other California sponge, with C. originalis tending to occur lower in the intertidal and also present in the shallow subtidal ( de Laubenfels 1932). Our recent collections have found all three species in both the subtidal and intertidal, but with different frequencies: 4 of 5 C. unoriginalis sp. nov. were found in the subtidal, but only 2 of 13 C. originalis and 1 of 8 C. pennata were found subtidally. Subtidal samples of the latter two species were found only on shore dives in very shallow water. The precise elevation/depth of each sample was not recorded, but we hypothesize that C. unoriginalis sp. nov. averages depths below the other two species—though they clearly overlap.

Clathria unoriginalis 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. Average differences in color and texture among species have been noted in specific locations, but overall, variability has thwarted all attempts to find useful field marks.

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 3. Maximum likelihood phylogeny of the cox1 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 7. Clathria unoriginalis. Field photos of holotype (A) and IZC00048439 (B). Cross sections showing choanosomal skeleton (C) and ectosomal skeleton (D). E: Thick style. F: Head of thin style and side view of chela. G: Chelae. C–G from holotype.