Phyllospongia foliascens (Pallas, 1766)

Fig. 26

Diagnostic features.

Specimen form is foliaceous and irregular flabellate branches, pale white color in life and when preserved, <0.5 mm thick. Numerous small oscula (<1 mm) scattered in the surface. Skeleton consists of interconnected reticulate fibers. This species was recently transferred from the genus Carteriospongia Hyatt, 1877 due to molecular phylogenetic analysis showing Carteriospongia foliascens as a clade member of Phyllospongia bergquistae Abdul Wahab & Fromont, 2020 . The original diagnosis describing a verrucose surface is characteristic for Phyllospongia foliascens, but with a fine and meandering surface patterning for Phyllospongia bergquistae (Bergquist et al. 1988; Abdul Wahab et al. 2021). Phyllospongia foliascens is a phototrophic species that mainly relies on symbiotic cyanobacteria for its nutrient cycle. This species is also able to endure high energy environments (Cleary et al. 2005).

Distribution and ecology.

Numerous individuals were found during the survey. Phyllospongia foliascens is widely distributed and has a high density in the Spermonde Archipelago (de Voogd et al. 2006). Our specimen was found at south-west of Samalona Island, reef flat; Gusung Tallang, turbid reef. This species has been recorded from shallow waters of the Red Sea, Indian Ocean, Australia, and Fiji (Abdul Wahab et al. 2021).