Diadromous Fishes, why they stay where they stay?!

Diadromous fishes are those who undergo migrations usually moving among habitats with different levels of salinity; for instance from rivers to the ocean and vice-versa.  The most common example are the Salmon and the European eel. In El Salvador we studied two species of diadromous fishes, the Tepemechin (Agonostomus monticola) and the Juilin (Sycidium multipunctatum) for one year in Acahuapa River. We were surprised that these fishes occurred always in the same place and we tried to observe what conditions were similar in their environments. Overall we observed that the sites where the fishes were living in, were surrounded by forest and small scale agriculture where the water quality was good. They totally avoided places surrounded by extensive agriculture and close to the city of San Vicente where the water quality was poor. It show us the importance that protecting our environment has on fish conservation and that fish DO care about the conditions of their habitat… after all no one likes to live in a trash bin.



Los peces diadromos son los que migran usualmente entre hábitats con niveles diferentes de salinidad por ejemplo de ríos al mar o viceversa. Los ejemplos más comunes son el salmón y la anguila Europea. En El Salvador investigamos dos especies de peces diadromos el Tepemechín (Agonostomus monticola) y el Juilín (Sycidium multipunctatum) durante un año en el Río Acahuapa. Nos sorprendió que estos peces solo se encontraran siempre en el mismo lugar y por ello intentamos observar qué habia en común entre estos ambientes. En general pudimos determinar que los sitios que los peces utilizaban estuvieron rodeados por bosque y agricultura a pequeña escala con una calidad de agua buena. Pero los peces evitaron completamente sitios donde la agricultura fue intensa y cercanos a la ciudad de San Vicente donde la calidad de agua es pobre. Esto nos demuestra que es importante proteger nuestro ambiente para conservar nuestros peces y que a los peces SI les importan las condiciones de su hábitat…. después de todo a nadie le gusta vivir en un basurero.

If you are interested in the full document you can download it here:



3 thoughts on “Diadromous Fishes, why they stay where they stay?!

  1. It interesting how selective these fishes are towards good water quality. This is important research – well done. Nice maps by the way.

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