<![CDATA[Coral reef ecosystems are centers of biodiversity with high productivity in tropical waters; however, information on reef fish communities and their behavioral interactions with coral colonies in the Seribu Islands remains limited. This study aimed to identify reef fish species, coral genera utilized by reef fishes, and variations in reef fish behavior associated with coral colony structures. An Underwater Video Survey (UVS) was conducted using systematic underwater video recordings at Panjang, Pelangi, Belanda, and Kelapa Islands, Jakarta, Indonesia. The Videos were analysed to identify reef fish species, coral genera, and behavioural patterns associated with coral colonies. A total of 215 reef fish species belonging to 82 genera and 29 families were identified across the study sites. Kelapa Island exhibited the highest species richness (120 species), followed by Belanda Island (119 species) and Panjang Island (107 species), while Pelangi Island showed the lowest richness (83 species). Sixteen coral genera were recorded, with Acropora and Porites being the most dominant and occurring at all study sites. In contrast, Cyhastrea, Echinophyllia, Echinopora, Monstastraea, Platygra, and Pocillopora were restricted to a single location. Acropora and Porites also supported the highest numbers of associated reef fish species. A total of 13 behavioural categories were observed. Feeding, roaming, and hovering were the dominant behaviours across all study sites, whereas cleaning, resting, ambush, and aggressive behaviours were less frequent. Variations in behavioural patterns among islands suggest that complexity influences both reef fish diversity and behavioural expression. These findings highlight the importance of structurally complex coral habitats in supporting reef fish diversity and ecological functions in the Seribu Islands.]]>
