<![CDATA[Crabs (Decapoda: Brachyura) play important ecological roles in coastal and intertidal ecosystems; however, information on crab diversity at Jumiang Beach, Pamekasan Regency, Madura, is still unavailable. Increasing tourism and coastal development activities may threaten intertidal habitats and biodiversity. This study aimed to identify crab species and evaluate the community structure of brachyuran crabs at Jumiang Beach based on diversity, evenness, and dominance indices. Sampling was conducted at three stations using direct collection and substrate excavation within 1 × 1 m quadrats along 10 × 10 m line transects. Specimens were preserved in 70% ethanol and identified morphologically using taxonomic references. Community structure was analysed using the Shannon-Wiener diversity index (H’), Pielou’s evenness index (E), and Simpson’s dominance index (D). A total of 286 individuals representing seven species and seven families were recorded, including Tubuca dussumieri, Thalamita spinimana, Nanosesarma batavicum, Macrophthalmus latifrons, Scopimera globosa, Mictyris longicarpus, and Ashtoret lunaris. The community showed moderate diversity (H’ = 1.72), high evenness (E = 0.88), and low dominance (D = 0.20). Scopimera globosa was the most abundant species (28.67%). The presence of Macrophthalmidae and Sesarmidae represents new records for the Madura coastal region. These findings highlight the importance of baseline biodiversity surveys for sustainable coastal management.]]>
