Copionodontinae


The Copionodontinae are a subfamily of catfishes of the family Trichomycteridae. It includes two genera, Copionodon and Glaphyropoma.

Classification

Copionodontines are remarkably primitive in body form, and lack many of the synapomorphies previously used to diagnose the family Trichomycteridae. Little doubt exists that the Copionodontinae form a monophyletic group, diagnosed by several unambiguous synapomorphies, including a unique dentition composed of spatulate teeth not seen anywhere else in the Trichomycteridae. A few characters also support the genera Copionodon and Glaphyropoma as monophyletic subunits.

Distribution and ecology

Copionodontines occur exclusively in the Chapada Diamantina; though the plateau is drained by four river basins, so far, these fish are exclusively found in drainages associated with the Paraguaçu River.
Copionodontines occupy the upper reaches of fast-flowing streams on rocky beds, often with tiny or no water flow in the dry season. Fish tend to concentrate on quiet, deep pools, though some individuals lodge in narrow rock crevices in fast-flowing sectors. Habitat preferences also vary according to species. Water in the upper reaches of the Chapada Diamantina is cool and usually black, but copionodontines are recorded in a few clear-water streams, as well. Usually, they share their environment with few or no other fish species.