Caquetala spectabilis (IMAGE) University of Massachusetts Amherst Caption UMass Amherst biologists compared museum collections of cichlid fishes from before a dam was closed in 1984 on the Tocantins River in the Brazilian Amazon to contemporary specimens taken from the Tucuruí Reservoir by fishermen 34 years later. They tested the idea that these fish could be expected to show body shape changes - in particular jaw bones - in response to habitat and foraging behavior shifts after the dam changed the waterway. Credit UMass Amherst/Albertson lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.