Copycat catfish evade competition

In the animal kingdom, it pays to look more dangerous and less tasty. It also helps if harmful species resemble one another so that predators might “learn” more easily to avoid both.

A new example of this form of mimicry has been discovered among catfish that live in the Amazonian basin, where a school of spiny, armored catfish (from the subfamily Corydoradinae) might contain three distinct species. The findings were described online January 5 in Nature.

“This research highlights the hidden diversity and complexity found within neotropical freshwater ecosystems,” Martin Taylor, of Bangor University’s Environment Centre Wales and co-author of the new study, said in a prepared statement. In addition to this semi-hidden biodiversity, species that were of closer genetic relation but lived farther apart had developed different patterning to look more like other local species. These details suggest not only convergent evolution, but also another selective force acting on the fish species.

The trouble with this sort of mimicry, first described by Fritz Müller in the 19th century, is that if co-benefiting mimics are competing for the same resources, the shared habitat loses some of its luster. For these Amazonian catfish, however, the researchers discovered that even though the fish swam the same waters, similar-looking species had slightly different lifestyles.

Read more hear ScientificAmerican

This entry was posted in Biology, Evolution. Bookmark the permalink.