Brachyuran Crab Diversity in the Mangrove Rehabilitation Site of Misamis Oriental, Mindanao Island, Philippines

This study was conducted to determine the crab diversity of the mangrove rehabilitation site in Misamis Oriental, Mindanao, Philippines. Specifically, it aimed to (1) determine the species composition of crabs in the mangrove area; (2) assess the species richness, relative abundance, and density of crab species; (3) evaluate the species diversity of crabs, and; (4) compare the diversity of crab species found in the mangrove area. Three sampling sites were selected using a plot sampling technique. A total of 163 individuals in 12 species of brachyuran crabs from seven families were recorded at the site. In terms of relative abundance, station 3 (Eastward zone) had the highest abundance with 93 individuals, followed by station 1 (Landward zone) with 47 individuals, and station 2 (Middle zone) with 21 individuals. Mictyris longicarpus had the highest population density of 0.12 individuals/m2, while Ptychognathus sp. and Portunus reticulatus had the lowest population density of 0.01 individuals/m2. The Shannon-Weiner diversity index revealed that sampling station 3 (Eastward zone) had the highest diversity index of H’ = 1.77 compared to stations 1 (H’ = 1.70) and 2 (H’ = 1.42). The key finding of this study showed that brachyuran crab species were more abundant and diverse in the zonation of new-growth mangroves compared to the old-growth mangroves.