A Possible Relation between the Occurrence of a Dendritic Organ and the Distribution of the Plotosidae (Cypriniformes)

Abstract

Three marine species of Plotosidae are found along the coastlines of the Indian and Pacific oceans, but the other 25 species occur exclusively in the Australian region. The majority of the Plotosidae are freshwater inhabitants, some of which are indigenous to both Australia and New Guinea. The marine members of the family and two freshwater members possess a dendritic organ. It is suggested that this organ has an osmoregulatory function.