Cliona wakatobiensis, Marlow, Joseph, Bell, James J., Shaffer, Megan, Haris, Abdul & Schönberg, Christine Hanna Lydia, 2021

Marlow, Joseph, Bell, James J., Shaffer, Megan, Haris, Abdul & Schönberg, Christine Hanna Lydia, 2021, Bioeroding sponge species from the Wakatobi region of southeast Sulawesi Indonesia, Zootaxa 4996 (1), pp. 1-48 : 14-16

Cliona wakatobiensis sp. nov.

Synonymy. Cliona aff. viridis sp. A sensu Marlow et al. (2019a, 2019b). Cliona aff. viridis sensu Marlow et al. (2018a, 2018b ).? Cliona varians sensu Calcinai et al. (2000)

Material examined. Cliona wakatobiensis sp. nov.: NMNZ PO.002261, Te Papa holotype, beta-morphology sponge from west of Hoga, Wakatobi, Banda Sea, sampled August 2017, 10 m, coll. C. Mortimer & A. Rovellini. NMNZ PO.002260, Te Papa paratype, beta-morphology sponge from north of Kaledupa, Wakatobi, Banda Sea, sampled August 2017, 10 m, coll. C. Mortimer & A. Rovellini. PK-LBB-01, slide of discarded beta-morphology sponge kept at VUW, sponge from west of Hoga, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. PK-LBB-02, slide of discarded beta-morphology sponge kept at VUW, sponge from west of Hoga, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. KDS-LBB-01, slide of discarded beta-morphology sponge kept at, sponge from north of Kaledupa, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. Specimens of other species used in comparison were: material for Cliona orientalis and and Cliona cribripora sp. nov. listed above.

Morphology and erosion. Sponge predominantly in beta morphology ( Fig. 6A ), very rarely in alpha form (possibly only very early recruits; Fig. 6B ). Light brown or tan ectosome, ochre-yellow choanosome when alive. Colour of ethanol-preserved specimens beige-grey. Individual organisms usually small (~ 75 cm 2), but capable of reaching 0.5 m 2. Regularly distributed oscular openings of 2–4 mm diameter, and smaller ostia. Surface tissue layer coating substrate 1 mm thick, with sponge evenly and densely pervading substrate beneath to 5–7 mm ( Fig. 6C ). Erosion contiguously removing roughly 50% of material, leaving irregularly shaped islands of substrate behind (visual assessment). Densely crowded chambers have irregular outlines and mean cross-sectional area of 2.0 mm 2 (± 1.1 SD).

Skeletal characteristics and presence of Symbiodiniaceae . Tylostyles in ectosome arranged in palisade with tips pointing outwards.Choanosomal tissue comprised of irregularly dispersed tylostyles and numerous spirasters. No spirasters found in ectosome. Abundant Symbiodiniaceae observed in surface tissue, and high levels of fluorescence measured (data not displayed).

Spicules. Megascleres—delicate, straight tylostyles with considerable variation in tyle morphology, occasionally as subtylostyles ( Fig. 6D ). Dimensions (min – mean – max and standard deviation): length 225 – 310 – 375 µm ± 32.9 SD; shaft width 3 – 4.8 – 7 µm ± 0.9 SD; and tyle width 4 – 7.5 – 10 µm ± 1.4 SD (means across four Wakatobi specimens, for N = 25 spicules each). Microscleres – slender spirasters with sparse spination along convex side of shafts, spines stalked and multisplit, ending in bouquets; additional amphiaster-like spirasters. Spirasters predominantly C-shaped, or straight with no spines on central portion of shaft, or with two or three bends ( Fig. 6E ). Shorter, straight, amphiaster-like spirasters, with terminal crowding of spines ( Fig. 6E ). Dimensions (min – mean – max and standard deviation): length 13 – 19.1 – 23.8 µm ± 2.8 SD; and shaft width 0.7 – 1.1 – 1.7 µm ± 0.2 SD (means across four Wakatobi specimens).

Molecular analysis. Cliona wakatobiensis sp.nov. was confirmed to be genetically distinct from morphologically similar species such as Cliona orientalis and Cliona varians ( Fig. 3 ). The division of Cliona wakatobiensis sp. nov. from other clionaid species in the analysis was supported by high ML bootstrap values and BI posterior probabilities (99/0.99). Cliona wakatobiensis sp. nov. was separated from the more distantly related Cliona cribripora sp. nov. + Cliona thomasi clade, and from the Cliona caribbaea + Cliona aprica + Cliona tenuis clade (Ct-complex; Escobar et al. 2012).

Habitat and occurrence in the Wakatobi. Common, most abundant at clear water sites and absent from highly sedimented sites. Spreading across bare substrate or recently dead massive coral colonies.

Remarks. As for Cliona cribripora sp. nov. and Cliona orientalis above, the spicule composition of tylostyles and delicate spirasters, and the association with Symbiodiniaceae , places the present Wakatobi specimens within the Cliona viridis species complex (see Schönberg 2002b). It was overall so similar to Cliona orientalis that we could not immediately separate the two species, but the molecular analysis did ( Fig. 3 ). As per Cliona orientalis , we compared the Wakatobi specimens with morphologically similar species that are known to occur in the wider Indo-Pacific region. The present sponge has spirasters with mostly bouquet-like spination, and we eliminated the species that have spirasters with shorter, more cylindrical, split spines, or discrete, undivided spines, or that lack microscleres (Appendix I). After that Cliona albimarginata , Cliona orientalis , Cliona thomasi and Cliona tropicalis remained for a closer comparison with Cliona wakatobiensis sp. nov. Of these, Cliona thomasi has shorter spiraster spines in denser distribution, and more of these spirasters are in the form of a C ( Fig. 1–2 in Schönberg 2002a, as Anthosigmella varians ; Mote et al. 2019). Moreover, its tylostyles are unusually robust, different from the Wakatobi sample with comparatively slender tylostyles. Cliona orientalis appears to have more regularly formed, more frequently helical spirasters, and our molecular assessment showed that our sample differed from Cliona orientalis ( Fig. 3 ). Some of the spirasters in our sample looked very much like the shorter, straight spirasters in Cliona tropicalis , but the tylostyles in Cliona tropicalis are significantly shorter than in the Wakatobi sponges. Cliona albimarginata was also described from Indonesia and had very similar spicule characters as the Wakatobi sponge, but the spines on Cliona albimarginata spirasters have a less pronounced bouquet-shape and are in a looser and more irregular arrangement than in our sponge. Moreover, we could not find the amphiasters of Cliona albimarginata in our specimen. Our sponge also had smaller oscules and lacked the distinctive white oscular collars of Cliona albimarginata . Based on the dissimilarities listed above and the phylogenetic isolation of the Wakatobi material, we concluded that Cliona wakatobiensis sp. nov. is a new species.

Figures

FIGURE 1. Map of sampling locations where bioeroding sponges were extracted. Right inset map (source https://commons. wikimedia.org/) and red dot indicate the position of the Wakatobi within the Indonesian region. Left inset map further shows the position of the Islands of Kaledupa and Hoga within the wider Wakatobi. Sites ‘Buoy 1 & 3’, ‘Kaledupa 1’ and ‘Kaledupa Double Spur’, ‘Pak Kasim’s’, ‘Ridge 1’ and ‘Sampela 1’ are abbreviated as B1, B3, K1, KDS, PK, R1 and S1, respectively.

FIGURE 2. Cliona cribripora sp. nov. (A) Field image of inhalant and exhalant papillae (latter lower left); (B) exposed erosion within carbonate rock; (C) tylostyles; (D & E) spirasters.

FIGURE 3. Phylogenetic tree showing the relationship of Wakatobi and other Cliona viridis complex spp. based on ITS 1, with new species from this study in bold. Topology generated from Maximum Likelihood analysis, and ML boostrap confidence values/BI posterior probabilities given above each branch. Spirastrella coccinea was chosen as an outgroup. Scale bar = substitutions per site, and white bar indicates break of 0.1 substitutions per site.

FIGURE 6. Cliona wakatobiensis sp. nov. (A) Field image of adult specimen; (B) field image of recruits/papillae; (C) crosssection showing sponge ectosome and extent of sponge erosion; (D) tylostyles; (E) spirasters.