Spatio-temporal variation of the structural organization of demersal communities in the Southwestern Gulf of Mexico

摘要: Structural patterns of a sublittoral community were analyzed through two-year series samples in the Southwestern Gulf Mexico. The groups involved study comprise fishes, molluscs, echinoderms and crustaceans. time-space progressions Second 0rder diversity values range between N2=5.3 N2=9.8 at depths 40 20 m respectively, first year samples. In second highest value (N2=22.2) was found 30 m. ordination data cluster principal components analy- sis show five assemblages: benthic, benthic-demersal, demersal, mid water column, temporary. There is striking difference trophic web structure dry season rainy season. Fish resource partitioning shows that are organized three guilds: ichthyophagous, carcinophagous omnivorous. However, partial overlap niches commonly observed, juvenile stages showed nar- rower spectrum than adults. Rev. Biol. Trop. 55 (2): 509-536. Epub 2007 June, 29. Veracruz shelf environment com- plex interaction adjacent land masses, coast- al waters near shore influenced by estuarine systems their inherent high productivity, coastal lagoon input, dynamics open Mexico waters. Relatively surface temperatures bring about great warming an increase moisture content overlaying air masses. Water mass distribution results from inflow Yucatan Channel, out- flow Straits Florida, conditions created local air-sea exchange processes, internal mixing well- defined masses bottom up: basin water, layer Antarctic intermedi- ate Mid-Atlantic element (Merino 1986). hydrography mixture these elements important as basic set- ting for resultant biological communities,