Many marine organisms require microhabitat as temporary or permanent hosts. Echinoderms are popular because of their complex body structures, which are ideal for hiding and surviving. Furthermore, they are widely distributed on the coral reefs in Thailand, but unfortunately that are still poorly studied.

This study aimed to investigate species diversity of marine organisms associated with echinoderm hosts by collecting samples from the coral reefs of Mu Ko Surin National Park in the daytime and nighttime by SCUBA diving from March 5-9, 2025. Twenty-nine marine organisms from 18 families, related to 19 species and 9 families of echinoderms, were found. The results also showed that marine organisms inhabiting the area select specific echinoderm hosts with two types of ecological relationships: commensalism (+/0) and parasitic (+/-) relationships.

The data presented in the present paper is the first dataset of a project: Species Diversity, Role, and Environmental Impact of Marine Organisms associated with Echinoderms to Promote Awareness of Marine Ecology and the Environment in Thailand, with an action plan for 2025-2027. We also expect that our findings will raise awareness about marine ecosystem to local people and public for the sustainability of marine resources in the future