There are a lot of fish on the coral reef. A new study by biologists at the University of California, Davis shows that much of the diversity is due to an innovation in fish feeding. The work is published in a journal.
Although jawed fish appeared in the fossil record 500 million years ago, they didn't show up in the teleosts until after the extinction of the dinosaurs.
"There may have been some biting done by teleosts before the end-Cretaceous, but our reconstructions suggest that it was very uncommon," said the graduate student in the UC Davis Department of Evolution and Ecology and Center for Population Biology.
Striking and biting.
Reef fish feed in many different ways. A lot of people suck food into their mouths. It is believed that this feeding is from teleosts. Ram biters are people who swim onto food with their mouths open.
Reef fish bite their food off hard surfaces. They have access to animals and plants that may be stuck to the surface of the water.
Corn and others in the UC Davis Department of Evolution and Ecology mapped 1,530 living species of reef fish onto an evolutionary tree. The rate of body shape evolution was studied.
Almost all of the fish in these lineages were feeders. Four in 10 reef species arenthic biters. The biting species are evolving in body shape at a faster rate than the others.
What made these changes happen? Coral reefs changed at the end of the Cretaceous, with more complex and branching structures. Teleosts had shorter jaws that were more suited for biting.
The changes opened up biting as an effective mode for fishes. The evolution of a wide variety of body shapes was promoted by biting.
"So once biting evolved, it was really able to take off, and this may explain the high rates of body shape evolution and diversity of biters that we see."
The paper has additional authors at UC Davis, Edward Burress and Christopher Martinez, as well as at USC.
More information: Katherine A. Corn et al, The rise of biting during the Cenozoic fueled reef fish body shape diversification, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2119828119 Journal information: Proceedings of the National Academy of Sciences
All Rights Reserved © 2024
