Presence and Genetic Identity of Symbiodiniaceae in the Bioeroding Sponge Genera Cliona and Spheciospongia (Clionaidae) in the Spermonde Archipelago (SW Sulawesi), Indonesia

Abstract

Members of the family Symbiodiniaceae form symbiotic relationships with several metazoan groups on coral reefs, most notably scleractinian corals. However, despite their importance to the health of coral reefs, their relationship with other host organisms such as bioeroding sponges (Clionaidae) is still relatively understudied. In this study we investigate the presence and identity of Symbiodiniaceae in Clionaidae species in Indonesia and evaluate findings related to the evolution and ecology of the host-symbiont relationship. Clionaidae were collected throughout the Spermonde Archipelago in Indonesia. Morphological and molecular techniques were used to identify the sponge host (28S ribosomal DNA) and their Symbiodiniaceae symbionts (ITS2). Seven Clionaidae species were found, of which four species contained Symbiodiniaceae. Cliona aff. orientalis, Cliona thomasi and Spheciospongia maeandrina were host to Cladocopium, while Spheciospongia digitata contained Durusdinium and Freudenthalidium. In the remaining species: Cliona sp., Cliona utricularis and Spheciospongia trincomaliensis no evidence of the presence of Symbiodiniaceae was found. Our results provide the first record of Symbiodiniaceae in the sponge genus Spheciospongia. Additionally, we provide the first findings of Freudenthalidium and first molecular evidence of Durusdinium in bioeroding sponges. Our results indicate coevolution between Spheciospongia digitata, Spheciospongia maeandrina and their symbionts. We discuss that the diversity of Symbiodiniaceae within bioeroding sponges is likely far greater than currently reported in literature. Considering the threat bioeroding sponges can pose to the health of coral reefs, it is crucial to understand Symbiodiniaceae diversity within Clionaidae and their effect on the functioning of Clionaidae species. We propose that the identity of the symbiont species is mostly related to the host species, but we did observe a potential case of environmental adaptation related to environmental stressors.

The highly developed symbiotic system between the solar-powered nudibranch Pteraeolidia semperi and Symbiodiniacean algae

“…Dinoflagellates belonging to the family Symbiodiniaceae, colloquially referred to as “zooxanthellae,” engage in symbiotic relationships with an array of shallow-water marine invertebrates, including cnidarians, 1 mollusks, 2 and sponges. 3 Typically, these host organisms furnish the dinoflagellates with requisite inorganic compounds, 4 and the algae reciprocate by supplying photosynthetic derivatives, such as saccharides and lipids, to their hosts. 5 Among these symbiotic associations, coral–Symbiodiniaceae interactions have garnered considerable scientific interest.…”

The volatilome of the cnidarian-dinoflagellate symbiosis

“…Symbiotic dinoflagellates were previously categorized into clades (e.g., A, B, C, etc.) based on DNA analysis of the second internally transcribed spacer (ITS2) of the rRNA gene, and remains a popular method with which to assess Symbiodiniaceae diversity (Fujise et al, 2018;van der Windt et al, 2020). Classification with this region alone has proven insufficient however, due to the multi-copy nature of this gene and high degree of intragenomic variability within this region (Hume et al, 2019).…”