Trophic analysis of the fish community in the Ciénega Churince, Cuatro Ciénegas, Coahuila
The fish community in the Churince system includes endemic, native and introduced species. Fish diets were analysed in order to evaluate the tropho-dynamics of the community. Nine sampling campaigns were carried out between February 2011 and May 2014, and 556 specimens of nine fish species were collected. Stomach contents were analysed using the Index of Relative Importance (IRI) and the Index of Absolute Importance (RIa). Similar groups were defined for the trophic chain using the average linkage method. Feeding strategies were stenophagic in only the species Herichthys minckleyi and euryphagic in the other eight species. The main food categories found in the stomach contents of the fish community were insects, crustaceans, gastropods, plants and teleosts. Four functional groups were defined for the trophic chain, with no top consumer fish species. Despite this, the fish were observed to be regulators, mainly of invertebrates. The chain reaction in the control of food was thus greater from the top to the bottom.