In days of increasingly threatened marine tropical ecosystems, it is important to improve knowledge on understudied but taxonomically rich habitats. If fish assemblages from barrier and fringing reefs are generally well studied, patch reefs are much less known. The objective of the present study (part of the EPICURE project) was to better understand taxonomic and functional specificity of patch reefs fish assemblages compared to the well-studied subtidal reef flat and outer slope habitats. Unbaited rotating video systems (STAVIRO) were used to quantify fish abundance on two sitesfrom the northern Mozambic channel (Mayotte Iris bank and Geyser bank). Taxonomic and functional diversity metrics were used to compare assemblages among habitats. None of the species diversity indices considered (Species richness, Shannon, Simpson and Pielou indices) showed significant differences among habitats, while most of functional richness indices showed differences (richness, specialization and originality). Overall, assemblages from patch reefs have more specialist and functionally original species than subtidal reef flat and outer slope. This work showed original assemblages on patch reefs and suggest that these habitats could be of particular interest for further investigation.