Cryptobenthic fish biodiversity and microhabitat use in healthy and degraded coral reefs in SE Sulawesi, Indonesia

Cryptobenthic fishes occur in high densities on coral reefs, though due to their small size and cryptic nature they are often overlooked when quantifying reef biodiversity. This study examines their distribution on shallow reefs in SE Sulawesi, Indonesia, and assesses changes in habitat utilization when subject to reef degradation. Cryptic fishes were sampled from dominant microhabitat types in healthy and degraded reefs within the Wakatobi Marine National Park located in SE Sulawesi. High biodiversity of cryptobenthic fishes was found with 50 species representing 13 families. Traditional metrics (i.e. density, diversity) showed few differences between healthy and degraded reefs, though further investigations revealed differences occurred in community composition. Additional analyses of individual species demonstrated that reef degradation could have positive or negative effects on populations depending on type and strength of habitat associations. In summary, cryptobenthic fishes are altering their habitat use on degraded reefs, which will likely have repercussions on coral reef dynamics.