Abstract

Common dolphinfish (Coryphaena hippurus) and pompano dolphinfish (Coryphaena equiselis) are economically and ecologically valuable pelagic fish found in tropical and subtropical oceans worldwide. Although they support both commercial and recreational fisheries, knowledge of their habitat use and ecology during early life is limited. Dolphinfish-larvae were collected during ichthyoplankton surveys of surface waters in the northern Gulf of Mexico (Gulf) in waters off of Texas and Louisiana (27 – 28° N 87 - 93° W) during June and July of 2007 and 2008. Dolphinfish larvae were relatively common in our sampling area (frequency of occurrence 63.2% and 55.3% in 2007 and 2008, respectively), and more than 700 larvae were collected during this two year study. Mean density (larvae/1000 m2) of dolphinfishes was higher in frontal zones (1.5) and anticyclones (1.0) compared to the open ocean (0.7) and cyclones (0.5), suggesting that these features may represent important habitats for dolphinfish larvae. Mean standard length varied between seasons with smaller larvae observed in June (7.5 mm) compared to July (15.4 mm). A published age-length key was used to calculate hatch-date distributions, which suggested that spawning times of larvae collected in our surveys ranged from late May to late July with the majority of larvae from June spawning events (54%). Results of this study indicate that dolphinfish larvae are abundant throughout the northern Gulf and that this region may represent important spawning/nursery grounds for these species.

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