Early Life Age and Growth of Caribbean Amphidromous Fishes

Artisanal fisheries for post-larvae and recreational fisheries for adult amphidromous fishes occur on tropical islands globally with large economic and cultural value. Despite the importance of amphidromous fishes to marine and freshwater ecosystems, their ecology and management have received little research attention. The life history of amphidromous fishes creates unique challenges to managing fisheries that occur at multiple life stages (i.e., during post-larval recruitment to freshwater and as adults). Post-larvae were sampled weekly in 2013 at the Arecibo and Mameyes river mouths in Puerto Rico and daily growth rings were counted from sagittal otoliths to describe temporal patterns in age and length at recruitment in addition to estimation of pelagic larval durations. Length and age at recruitment of amphidromous fishes generally increased over the sampling period and provide insight on potential mechanisms responsible for recruitment. For example, River Goby Awaous banana sampled from the Arecibo River exhibited greater variation in age (46–79 d, CV 11%) than total length (13.5–16.7 mm, CV 4%), suggesting recruitment timing to freshwater habitats may be size-dependent despite a wide range in ages and protracted spawning period. Overall, results of this study provide crucial information for the ecology and management of Caribbean amphidromous fishes.