Recruitment Phenology of Caribbean Amphidromous Fishes

Amphidromous fishes are a major component of tropical coastal and island lotic fish assemblages.  In the amphidromous life-history, adults occupy and spawn in freshwater streams, their embryos or larvae are transported downstream, larvae grow and develop in the marine environment, and post-larvae recruit to the estuary and undergo metamorphosis during ingress to the river.  Dispersal during the marine larval phase and subsequent recruitment by post-larvae allows for population colonization, re-colonization, and replenishment.  Post-larval recruitment is also important for ecosystem services provided by amphidromous fishes.  Valuable artisanal fisheries for amphidromous post-larvae are widespread, and post-larval recruitment is important for estuarine and stream recreational fisheries globally.  Despite the importance of post-larval recruitment for Caribbean freshwater fisheries and ecosystems, their ecology and management have received little research attention.  We quantitatively sampled amphidromous post-larvae at the mouths of the Arecibo and Mameyes rivers in Puerto Rico during the 2013 to 2014 recruitment season.  Our results reveal relationships of amphidromous post-larval recruitment with the lunar cycle and document intra-annual variation in recruit abundances. This study is the first to determine post-larval recruitment phenology in amphidromous fishes of Puerto Rico, which provides crucial information for the ecology and management of Caribbean stream fishes.