Assessing cryptic marine fauna diversity as underwater macrophotography (UMP) objects in Sempu Strait, Indonesia

Cryptic marine fauna refers to organisms that live inside habitats that hidden from direct exposure to their outer environment. Its cryptic nature made these animals rarely observed, and hence understudied. Whereas, they are very popular among experienced divers alike as underwater macrophotography objects. The aim of this study is to assess the diversity of cryptic marine fauna on the proximity of coral reef area at Sempu Strait to bring up its underwater macrophotography tourism potential. While the definition of cryptic marine fauna itself could include any major group of marine organisms, we limit the extent of our study only into the four most popular animal groups in underwater macrophotography which are: fishes, sea slugs, arthropods, and flatworms. We conducted underwater surveys using roving diver technique spanning from October 2017 to June 2019 at eleven dive sites of Sempu Strait and yielded 84 species that consists of 45 species of sea slug, 29 Species of fish, 8 species of arthropods, and 2 species of flatworms. The overall fauna diversity shows that Sempu Strait has high diversity of sea slug and cryptic fishes, while the site-specific diversity shows that Stumbut dive site has the highest marine cryptic fauna diversity