Spatio-temporal dynamics of larval fish in a tropical estuarine mangrove: example of the Mahury river estuary (French Guiana)

The present study focuses on the structure and dynamics of the ichthyoplankton community of the Mahury estuary (French Guiana) and the factors that influence them. Data were collected on three mangrove sites located in the inner, middle, and outer areas of the estuary. More than 45 000 larvae were collected, representing 31 families and 67 taxa. The community was numerically dominated by few species; Engraulidae was the most abundant family, followed by Gobiidae, Eleotridae, and Sciaenidae. As expected, the most abundant larval taxa were estuarine and mangrove species, with the addition of freshwater species in the inner area of the estuary and taxa with marine affinities in the outer area. The densities of most species were influenced by site more than by season. Temporal variations in the dominant species were influenced largely by their life history strategy, with a majority of the fish species spending their entire life history in mangroves and estuaries.