Meiofauna del Golfo de Guayaquil, Ecuador (Río Guayas, Canal Cascajal y Estero Salado), obtenida en abril de 1997

Abstract

El presente trabajo es la segunda contribución en el Ecuador, al mejor conocimiento de la meiofauna bentónica del Golfo de Guayaquil.

From the analysis of 20 sediments samples in 20 stations, obtainded on April/97, located in the Gulf of Guayaquil interior, that are included: Río Guayas, Cascajal Channel and the Estero Salado. 3281 organisms of the benthonic fauna in 200 cm2 of surface. Eleven (11) Phylum were observed, represented for 19 groups of benthonic microinvertebrates, they are the following Phylum: Nematoda, Rotifera, Artropoda (Crustacean, Insect and Mite), Annelida (Polichaeta y Oligochaeta), Mollusca (Pelecypod y Gastropod), Kinorryncha, Gastrotricha, Lfophorate (larvae), Echinodermata (brachiolaria larvae), Coelenterata (Hydrozoa) and Protozoa (Foraminífera). The Phylum Gastrotricha, the Class Insect of the phylum Arthropod and the larvae of Lofophorate group are the first mentions for the Gulf of Guayaquil. The Gastrotricha were observed in the low salinity environment of the Guayas River, while the insect were observed in the Guayas River (Est. 6) and the Estero Salado (Esta. 14). Only one larvae of Lofophorate was founded in the Estero Salado (Est.14). The Phylum Mollusca (Velliger of Pelecypods and Gastropods) and Echinodermata (Brachiolaria larvae) are not true representatives of the Meiofauna, because are "normal larvae" and are not adult organisms. The highest diversity and abundance of organisms are located in the Estero Salado and, Channel Cascajal, while the lowest abundance is in the Guayas River, with the exception of the Gastrotricha phylum. The principals groups of the Meiofauna and the relationship with the Salinity, temperature, oxygen and pH, are presented on figures and tables.