FLAGSTAFF, Ariz., Oct. 7 (UPI) — Some aquatic fish can move effectively on land without specialized anatomical attributes, a finding with evolutionary implications, a U.S. scientist says.
Biology Professor Alice Gibb and her research team at Northern Arizona University said their study suggests the nervous system, in its control of bones and muscles, can allow a new behavior to appear without necessarily bringing about a physical change.
“This shows that you don’t have to have legs or rigid pectoral fins to move around on land,” Gibb said. “So if you go back and look at the fossil record to try to say which fish could move around on land, you’d have a hard time knowing for sure.”
The researchers studied a small fully aquatic fish, the mosquitofish, and found it had the ability to move outside of water with apparent skill and purpose.
The research implies that “the invasion of the land by vertebrates may have occurred much more frequently than has been previously thought,” Gibb said.
“Maybe fishes that are very good at jumping are poor swimmers,” she said. “We want to look at the compromises that may have been made to favor one behavior over another.”