Cliona cribripora, 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 : 5-7

Cliona cribripora sp. nov.

Synonymy. Cliona aff. viridis sp. B sensu Marlow et al. (2019a, 2019b)

Material examined. Cliona cribripora sp. nov. — NMNZ PO.002259, Te Papa Museum holotype, alphamorphology sponge from north of Kaledupa, Wakatobi, Banda Sea, sampled August 2017, 10 m, coll. C. Mortimer & A. Rovellini. NMNZ PO.002255, Te Papa Mueum paratype, alpha-morphology sponge from north of Kaledupa, Wakatobi, Banda Sea, sampled August 2017, 10 m, coll. C. Mortimer & A. Rovellini. PK-BlA-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. PK-BlA-02, slide of discarded specimen kept at VUW, alphamorphology sponge from west of Hoga, Wakatobi, Banda Sea, sampled between March and August 2014, 3– 20 m, coll. J. Marlow. B3-BlA-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. Specimens of other species used for the purpose of comparison were samples as listed below for Cliona orientalis and Cliona wakatobiensis sp. nov.

Morphology and erosion. Exclusively in alpha form ( Fig. 2A ). Obvious differences between inhalant and exhalant papillae. Both with brown outer edge, but exhalant papillae with slightly raised oscular ring with grey rim, inhalant papillae flush with substrate surface and with grey sieve-like structure formed by dense spicule fibres separating groups of pores. Exhalant papillae circular to oval, inhalant papilla form variable and with irregular outline. Preserved papillae 2–13 mm in diameter, frequently merged, and with short papillar canals leading to erosion zone of <10 mm into substrate ( Fig. 2B ). Erosion comprised of irregularly shaped, very small (crosssectional area 0.7 mm 2 ± 0.2 SD), erosion chambers separated by small islands of substrate. Choanosome yellow when alive. External and internal colour of ethanol-preserved specimens grey-brown.

Skeletal characteristics and presence of Symbiodiniaceae . Papillar tylostyles in dense palisade with tips pointing outwards. Choanosomal skeleton comprised of sparse and irregularly dispersed tylostyles and spirasters. Abundant Symbiodiniaceae observed in surface tissue, and high levels of fluorescence measured (data not displayed).

Spicules. Megascleres—Tylostyles more robust compared to the other Wakatobi Cliona spp. ; shaft shape variable, from straight to strongly bent centrally ( Fig. 2C ). Terminal tyles predominantly spherical or drop-shaped, but occasionally elongated. Dimensions (min – mean – max and standard deviation): length 276 – 327.9 – 392 µm ± 27.1 SD; shaft width 6.0 – 9.2 – 11.5 µm ± 1.1 SD; and tyle width 10.0 – 12.2 – 15.3 µm ± 1.2 SD (means across four Wakatobi specimens; N = 25 spicules each). Microscleres—Very rare, slender spirasters with discrete, thin, thorn-like spines projecting from convex side of spicule shaft. Spiraster curvature pronounced, sometimes with middle bend largest, number of bends variable, ranging from 0 in straight spirasters to 7 bends (average 4; Fig. 2D & E ). Spiraster dimensions (min – mean – max and standard deviation): length 18 – 24.3 – 41 µm ± 7.2 SD; and shaft width 0.5 – 0.9 – 1.0 µm ± 0.1 SD (means across four Wakatobi specimens).

Molecular analysis. Phylogenetic analysis ( Fig. 3 ) placed specimens identified as Cliona cribripora sp. nov. into the same clade as the morphologically distinct Cliona thomasi . This clade was closely related to, but distinct from Cliona orientalis . It also differed from Cliona wakatobiensis sp. nov. and from the Cliona caribbaea + Cliona aprica + Cliona tenuis clade (referred to as the Ct-complex by Escobar et al. 2012).

Habitat and occurrence in the Wakatobi. Very common at all sites; usually on bare substrate or dead massive coral, but also on consolidated rubble. Most abundant between 7–12 m depth, except at highly turbid sites, where the species was restricted to shallower depths than 7 m.

Remarks. The spicule composition of tylostyles and delicate spirasters in combination with being associated with Symbiodiniaceae and the positioning within our phylogenetic tree placed these Wakatobi specimens within the “ Cliona viridis species complex” ( Figs. 2 & 3 ; Schönberg 2002b). Despite phylogenetic similarity of Cliona cribripora sp. nov. with Cliona thomasi (ITS1), substantial morphological differences between the species meant conspecificity could be discounted. The clearly sieve-like structure of the inhalants of Cliona cribripora sp. nov. does not occur in Cliona thomasi ( Mote et al. 2019) . Additionally, and unlike Cliona cribripora sp. nov., Cliona thomasi has characteristic robust, predominantly straight tylostyles and predominantly C-shaped spirasters with bouquet-spination ( Mote et al. 2019). Other known Cliona species that are brown, olive-coloured or ochre, have similar spicule characters and were recorded in endolithic morphology from the Indo-Pacific and Eastern Pacific are Cliona albimarginata , Cliona caesia , Cliona flavifodina , Cliona minuscula , Cliona orientalis , Cliona papillae , Cliona raromicrosclera , Cliona reticulata (this species lacks Symbiodiniaceae , however; Ise & Fujita 2005), Cliona subulata , Cliona tropicalis and Cliona vallartense (see Schönberg et al. 2017a for faunistic lists). As the Cliona viridis complex has historically created much confusion (e.g. Rosell & Uriz 1991), and the number of species we needed to compare was quite large, we tabulated respective characters of known species to compare with our material (Appendix I; taxon authorities listed within). Thereby, we could quickly exclude all other species in which the spination of the spirasters exhibits split ends or bouquets, or species without microscleres (Appendix I). This left us with Cliona flavifodina and Cliona subulata for comparison. Cliona flavifodina was excluded for having yelllow- ish circular papillae and not having been described with the sieve-like structures that are so characteristic in the Wakatobi material ( Rützler 1974). The spination on Cliona flavifodina spirasters also appears to be more robust, longer and more widely spaced. Moreover, Cliona flavifodina spirasters are about 12% of the length of the tylostyles, while they reached only about 7% in the Wakatobi sponge (Appendix I). Cliona subulata could not be as easily discounted. The type specimen was found together with Cliona mucronata and Cliona ensifera in a piece of substrate with Isis sp. bamboo coral ( Sollas 1878). These taxa have previously been observed in Indonesia and elsewhere in the southwestern Pacific ( Calcinai et al. 2005; Schönberg et al. 2006; Rowley et al. 2015). Both, Cliona subulata and our sponge extended through coralline algae. Further considerations were difficult, however, because the original description of Cliona subulata is insufficient for taxonomic comparison and only provides basic information about the spicules ( Sollas 1878). All spicules in Sollas’ plate II are supposed to be to scale. By comparing known spicule lengths for Cliona mucronata with the drawing for Cliona subulata spicules, we estimated that the tylostyle lengths of Cliona subulata and the Wakatobi sponge were likely well matched. The spirasters appeared to be about twice as long in Cliona subulata than in the Wakatobi sponge, but in Sollas’ drawing they also seemed to be too long for their shape, and we were not sure how reliable that drawing was. We tried to find type material for Cliona subulata , which could have originated from the 1872-76 Challenger Expedition and would most likely be in the United Kingdom. We could not find a respective entry in the catalogue of the British Museum (http://data.nhm.ac.uk). From 1873-1880 and thus around the time of the description for Cliona subulata Sollas had worked in Bristol and was partly engaged as a museum curator ( Vincent 2004). We were informed that the Bristol Museum used to hold a few sponges authored by Sollas, but that these were lost during World War II (R. Rowson pers. comm. 2018). Reduced to Sollas’ drawing and our SEM images as means for comparison, we thought that the spiraster spination was straighter and sparser in Cliona subulata than in the Wakatobi sponge, and that Sollas would probably have noticed the more strongly bent tylostyles we observed in our material. To settle the issue, we decided to describe Cliona cribripora sp. nov. as a new species.

Figures

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.