Feeding habits of Floridichthys polyommus Hubbs, 1936 (Pisces: Cyprinodontidae) in two coastal lagoon systems

Abstract

The feeding habits of Floridichthys polyommus (Pisces: Cyprinodontidae) were determined and compared spatially and seasonally between two coastal lagoon systems in Yucatan Peninsula. A total of 445 and 561 stomach contents were analyzed from the lagoons of Puerto Viejo (Quintana Roo) and Chelem (Yucatan), respectively. This specie presents a wide trophic generalization, including 126 alimentary items in Puerto Viejo and 80 in Chelem. It consumes basically microcrustaceans, phytoplankton, and macrophytes. However, trophic preferences were different spatially and seasonally between both systems. In Puerto Viejo F. polyommus feeds on microcrustaceans, whereas in Chelem it consumes phytoplankton. Considering its trophic ontogenetic variation, smaller individuals preyed on microcrustaceans and the larger ones on phytoplankton or macrophytes. In Puerto Viejo, microcrustaceans were the principal and more abundant food during the dry season (35.1%), while during the rainy and cold seasons phytoplankton was the most representative item. Phytoplankton was always the most abundant food in Chelem all year long, with an increase in the dry season (51.6%). Spatial and seasonal trophic variation between both lagoons can be related to the food components availability in each system and to hydrological variability for each season of the year.