Bioerosion traces of an endolithic clionaid sponge on the gastropod shell of Tibia curta Sowerby II, 1842

Bioeroding sponges are significant contributors to the ocean’s carbonate system. They have long been recognized as molluscan shell eroders and are capable of excavating calcareous substrates. Because of their propensity to penetrate calcareous substrates, the functional significance of bioeroding sponges is increasingly acknowledged. The present study reports the bioerosion traces of Cliona cf. celata on the gastropod shell of Tibia curta Sowerby II, 1842, for the first time. On the gastropod shell, Cliona cf. celata was evident as circular perforations with a diameter of 0.2–0.3 cm. A total of 356 circular perforations were observed on the external surface of the shell, and fused papillar perforations measured 0.4–0.6 cm in length and 0.2 cm in width on the internal shell surface. SEM analysis of the shell fragment revealed that Cliona cf. celata had multifaceted pits with smooth ornamentation.