Pelagic amphipods from the neritic province of the southern Gulf of Mexico

Density data of the pelagic amphipods from the neritic province of the southern Gulf of Mexico are presented. This information is derived from oceanographic studies conducted during the dry (May) and nortes (November) seasons as part of the project entitled “Monitoreo de Pre-reclutas de Especies Estuarino-Dependientes” (MOPEED), carried out in 1995 by the Universidad Nacional Autónoma de México. A total of 187 zooplankton samples were collected at 28 sampling stations and five sampling levels, ranging from 0 to 105 m, depending on bottom depth. Sampling was performed using a stratified opening-closing net system with a 500 µm mesh size; each net was equipped with a flowmeter to calculate the volume of filtered water. Biological material was fixed in 4% formalin and subsequently preserved in 70% alcohol. A total of 39,329 individuals were separated and identified using specialized literature, and their abundance was expressed as individuals per 1,000 m³. In total, 86 taxa were identified, most of them occurring in both studied periods, and the dominant species was Lestrigonus bengalensis. The greatest abundance was recorded during the nortes season, especially at stations located on the continental shelf, while stations on the slope recorded a lesser density but a higher species richness.