Cliona orientalis Thiele, 1900

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 : 8-10

Cliona orientalis Thiele, 1900

Synonymy. Cliona viridis sensu Bergman (1983) . Not: Cliona orientalis sensu Thomas (1972, 1979 ) = Cliona thomasi , see Mote et al. (2019).

Material examined. Cliona orientalis —KDS-BeA-01, slide of discarded specimen kept at VUW, alphamorphology sponge from north of Kaledupa, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. KDS-BeA-02, slide of discarded specimen kept at VUW, alpha-morphology sponge from north of Kaledupa, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. PK-BeA- 01, slide of discarded specimen kept at VUW, alpha-morphology sponge from west of Hoga, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. CS-MAG-b-14, slide of discarded specimen kept in CS’s personal collection, beta-morphology sponge from Magnetic Island backreef, Great Barrier Reef, Australia, sampled 26. December 1997, 5 m, coll. C. Schönberg. Specimens of other species used in comparison: BMNH 1887.6.1.4, Cliona thomasi , beta-morphology sponge in coral substrate. Erroneously identified by Carter (1887) as Suberites coronarius (a synonym of Cliona varians ), his field reference 73; Mergui Archipelago, Myanmar, Andaman Sea, 1. June 1887; and samples as listed above and below for Cliona wakatobiensis sp. nov. and Cliona cribripora sp. nov.

Morphology and erosion. In the Wakatobi exclusively in alpha form ( Fig. 4A ), but circular to irregular-shaped papillae frequently merging, 1–15 mm in diameter, dark brown with pale grey oscular rings protruding 1 mm above papillar surfaces when extended ( Fig. 4B ). Short (2–6 mm) papillar canals leading to shallow, irregular-shaped erosion chambers (cross-sectional area 0.8 mm 2 ± 0.2 SD), separated by irregularly shaped contiguous islands of substrate ( Fig. 4C ). Choanosome yellow-ochre, densely filling erosion chambers. Colour of ethanol-preserved specimens beige-grey.

Skeletal characteristics and presence of Symbiodiniaceae . Papillar tylostyles densely packed in palisade, with tips pointing outwards. Abundant spirasters irregularly dispersed beneath palisade, lining papillar canals and in choanosome. Tylostyles less frequent in choanosome than in surface and irregularly dispersed. Symbiodiniaceae crowded in surface, with high levels of measured fluorescence (data not displayed).

Spicules. Megascleres—Straight to slightly curved, slender tylostyles with pronounced tyles ( Fig. 4D ). Dimensions (min – mean – max and standard deviation): length 250 – 309.8 – 385 µm ± 29.3 SD; shaft width 4 – 5.4 – 7 µm ± 0.6 SD; and tyle width 5 – 8.3 – 10 µm ± 1.2 SD (means across three Wakatobi specimens with N = 25 each). Microscleres – Spirasters, either straight, C-shaped or more often helical with three to four bends. Spines arranged in stalked bouquets along convex sides of spicule shaft and in terminal clusters ( Fig. 4E ). Spiraster dimensions (min – mean – max and standard deviation): length 15 – 22.5 – 27 µm ± 3.2 SD; and shaft width 0.7 – 1.0 – 1.5 µm ± 0.2 SD (means across three Wakatobi specimens).

Habitat and occurrence in the Wakatobi. Easily overlooked or very rare, on bare substrate, coralline algae and oyster shells, at low turbidity sites and in shallow waters (found at max. 7 m depth).

Remarks. The spicule composition of tylostyles and delicate spirasters in combination with the presence of Symbiodiniceae placed these Wakatobi specimens within the “ Cliona viridis species complex” (see Schönberg 2002b). Comparisons of the Wakatobi material and the characterstics of other Cliona viridis species (Appendix I) helped us to arrive at the decision that the Wakatobi material here described was Cliona orientalis . We allowed that Cliona species that have been recorded as occurring exclusively in thinly encrusting beta morphology would likely have an early-recruitment alpha stage, and that colour and some morphometric dimensions might vary with environmental parameters. Based on characters listed in Appendix I and the reasons listed below we therefore excluded the following Cliona species :

• Cliona albimarginata —Occurs in the area, but the tylostyle shape differs, displaying subtle, elongated tyles. It has more than one spiraster type, and the helical spirasters do not have the wide, pronounced bouquets found in the Wakatobi material. To date it has not yet been observed in alpha-morphology.

• Cliona caesia —Occurs in the area, but has characteristic, straight tylostyles with comparatively wide tyles, and has no spirasters. Extended papillae are stalked, distally flattened and widened, resembling an inverted umbrella.

• Cliona flavifodina —Was originally described from the Caribbean, reported from the Mexican Pacific, and differs from the present species by having very different spirasters, with long, mostly discrete spines.

• Cliona minuscula —Likely occurs in the area, but the tylostyles and papillae are significantly shorter and smaller, respectively, has no spirasters.

• Cliona papillae —Occurs in the Mexican Pacific, and unlike the Wakatobi sponge has elevated papillae that are distally widened. Spiraster spines are mostly discrete.

• Cliona raromicrosclera —Occurs in the eastern Pacific, has comparatively long tylostyles and comparatively robust spirasters with dissimilar spination, not forming pronounced bouquets.As a thickly encrusting or sub-massive form it is unlikely to commonly develop in alpha morphology.

• Cliona reticulata — Described from the Ryukyu Islands, has three types of spirasters, including different types than presently observed (Appendix I), and very small papillae. It lacks the symbiotic dinoflagellates .

• Cliona subulata —Unknown origin, but apparently from the Indo-Pacific. It differs from our material by having spirasters with straight, discrete spines.

• Cliona thomasi —Described from western India in beta-morphology. It has very robust tylostyles and a high abundance of anthosigma-like, C-shaped spirasters, not observed in our material.

• Cliona tropicalis —Occurs in the Mexican Pacific, has very small papillae and rounded erosion chambers, and its spirasters are predominantly straight and have less pronounced spine bouquets.

• Cliona vallartense —Occurs in the Mexican Pacific, has variable tyle morphologies, comparatively robust spirasters lacking pronounced spine bouquets and penetrates the substrate to exceptional depths.

The Wakatobi specimens very much resembled Cliona orientalis in that the alpha form develops comparatively large papillae that often have an oval to irregular outline, or they merge. The tylostyles have comparatively distinct, round to inverted drop-shaped tyles, and the spirasters are delicate, mostly helical, with bouquet-shaped multiplit spines on short stalks. The erosion traces are irregular, making it difficult to recognise distinct erosion chambers. All these characters were found in our specimens, which—like the type material—were sampled from the Coral Triangle. Cliona orientalis was originally described in both the alpha and beta form from Ternate in Indonesia ( Thiele 1900) and has since been reported from New Caledonia ( Kelly-Borges & Vacelet 1998), the Great Barrier Reef ( Schönberg 2000) and Western Australia ( Fromont et al. 2005).

Figures

FIGURE 4. Cliona orientalis. (A) Field image of sponge; (B) close-up field image of papillae; (C) cross-section of erosion; (D) tylostyles; (E) spirasters.