Distribution, abundance and diversity of fish larvae in Santa Rosa coastal lagoon, Sonora, Mexico

Abstract

In order to determine the distribution, abundance and diversity of fish larvae in the coastal lagoon of Santa Rosa, Sonora, monthly surface samplings of plankton were carried out from November 1987 to October 1988. A cylindroconical net of 55 cm diameter and 505 µm mesh size was used. Forty-one types of larvae representing 20 families were collected, of which 15 were identified to species, 10 to genus and 15 to family. The highest abundance was recorded in March (3,930 organisms/100 m³) and the lowest in July (159 organisms/100 m³). The family Gobiidae constituted 60.7% of the total catch, Atherinidae 9.5%, Clinidae 5.6% and the rest of the families less than 5% each. The values of the diversity index were influenced by the family Gobiidae, which maintained its dominance despite the great tidal exchange, and the fact that no spatial abundance gradient was found could be attributed to this.