Shallow-Water Benthic Decapod Crustaceans of Chankanaab Park, Cozumel Island, Mexico

Abstract

Chankanaab Park is a protected area in Cozumel Island, Mexico, that includes a portion of the coral reef marine environment, and a small inland lagoon connected to the sea by a narrow underground tunnel, 60 m long. The present study is the first addressing the benthic decapod fauna in this Park. Because of the protected status and the srnall area of the marine zone of the Park (-7 ha), collections were made only by hand using SCUBA diving. Seventy-three de-capod species belonging to 22 farnilies were identified in the Park area. Twenty-one species occurred in both habitats (rnarine zone and lagoon), indicating that there is faunal exchange behveen both sites through the tunnel , either by means of larval phases, or by crawling or walking individuals. In fact, nine of these 21 species were actually recorded in the tunnel. Of the rernaining species, 49 were restricted to the marine zone, and one was found solely in the lagoon. The higher species richness in the marine zone seerns related to the wider variety of habitats in that area, especially living substrates such as erect sponges, cctccorals, seagrasses, and anemones, which harbored a number of associated decapod species but were completely absent frorn the lagoon. Although no human activities are allowed in the lagoon, and fishing is forbidden in the whole Park area, the Park receives a daily average of 1000 visiting tourists, most of which conduct aquatic or underwater activities in the rnarine zone. Further protection of the live substrates in the rnarine zone is recornmended, to warrant the preservation of the rich decapod fauna in the area.