"When you do a study like this, you have to ask what your control is," Gibb said. "If a known amphibious fish is a good jumper, then what's a bad jumper?"
Enter the guppy, a fully aquatic fish.
"The guppy jumped almost as well as the amphibious fish did," Gibb said. "And no one has ever suggested that a guppy is an amphibious fish." As a result, "we put everything we could get our hands on" in front of a high-speed camera, Gibb said. Some of those additional subjects included the mosquitofish, which has been introduced into tributaries of Oak Creek, and a common pet store zebra fish, which is a very distant relative of guppies and mosquitofish.
The mosquitofish "has become our lab rat," Gibb said. "It's accessible, it comes from a group that has other jumpers, and it's been reported that this fish jumps out of the water to get away from predators and then jumps back in."
That particular escape behavior, Gibb said, has never been filmed. Similar stories about other fish add to mostly anecdotal literature on the topic that "tends to be old and very diffuse."
Today's high-speed video systems give Gibb an opportunity to change that. What the cameras reveal is that both species produce a coordinated maneuver in which the fish curls its head toward the tail and then pushes off the ground to propel itself through the air.
Gibb and her team have discussed going into the field to capture video of fish performing this behavior in the wild. But for now Gibb and her colleagues are endeavoring to determine if there is directionality to voluntary locomotion on land and to investigate the genetic basis of the jumping behavior.
"Maybe fishes that are very good at jumping are poor swimmers," Gibb said. "We want to look at the compromises that may
|Contact: Eric Dieterle|
Northern Arizona University