Benthic Foraminifera and Thecamoebians of Godineau River Estuary, Gulf of Paria, Trinidad Island

Abstract

In the Godineau River Estuary, located in Trinidad Island (off the northeast coast of Venezuela), were found 114 taxa of foraminifera and 17 of thecamoebians in the dead fauna. Most of the identified foraminiferal species were rare because they were transported from the Gulf of Paria to this estuary. The autochthonous foraminiferal assemblage was represented by several tropical estuarine species such as Ammonia tepida, Ammotium salsum, Arenoparrella mexicana, Cribroelphidium excavatum, Ammonia parkinsoniana, Haplophragmoides wilberti, Miliammina fusca and Ammotium cassis. The thecamoebians assemblages, found in the inner part of this estuary, were dominated by Cyclopyxis spp., Centropyxis spp., Difflugia corona and Difflugia urceolata. The relative abundance of the main species of foraminifera and thecamoebians were analyzed through Q-mode and R-mode cluster analyses. Statistical results revealed the presence of three different environments in the Godineau River Estuary related to different hydrodynamic conditions and more or less oceanic or fluvial influence. The first sector represents the most confined region of the estuary and was mainly composed by agglutinated foraminifera together with thecamoebians. The second sector was located in the middle part of the estuary and was associated with the presence of brackish waters. The third sector denotes the outermost part of the estuary characterized by the greatest hydrodynamic activity and highest oceanic influence within the estuary. This sector was marked by the occurrence of a large number typical-marine foraminifera species.

Keywords

• Estuarine compartments
• Foraminifera
• thecamoebians
• microtidal estuary
• tropical coastal environment