Research Advances in Environment, Geography and Earth Science Vol. 7

Abstract

During the warm period of El Niño in the spring and fall of 1998, the average water temperatures were very close, between 21.1 and 20.9°C (± 0.2°C); However, in the summer of 1998 the average was higher (24.3°C), in contrast, during the cold period of La Niña in the winter season of 1999 an average of 13.4°C was recorded. The composition of fish fauna of San Ignacio Lagoon comprised 44 species. Eight species were present during all seasons: Eucinostomus dowii, Hippocampus ingens, Pleuronichthys guttulatus, Paralabrax maculatofasciatus, Paralichthys californicus, Sphoeroides annulatus, Sphoeroides lispus and Urobatis halleri. The species with the highest abundance during El Niño were: Paralabrax maculatofasciatus, Eucinostomus dowii; whereas during La Niña they were: Sphoeroides lispus, Paralabrax auroguttatus and Sphoeroides annulatus. In relation to zoogeography affinity in fishes, the provinces and regions were: the Panamic (37%), Californian (32%), Eastern Pacific (18%), Mexican (11%), and the Cortez province (2%). The fish species of tropical affinity found during the El Niño event in 1997-1998 were: Hoplopagrus guntheri, Eucinostomus gracilis, Exerpes asper, Achirus mazatlanus, Rhencus panamensis, Cyclopsetta panamensis, Bairdiella icistia, Microlepidotus inornatus, Orthopristis reddingi, Sphoeroides lispus, and Urobatis maculatus.