Most of the fishes They depend on water for food, using suction to capture their prey. In the case of brunettes, like the snowflake or starry (Echidna nebulosa), they use a second pair of jaws located in their throat called pharyngeal jaws they also have teeth, to capture their prey, since their head is too narrow.
Most fish need water for food. This is the first example of a fish that can feed on land without relying on water
These eel fish are the only animals that use the pharyngeal jaws to actively capture and retain a dam. This exceptional feeding mechanism with the pharyngeal jaws was first described by the researcher Rita Mehta, associate professor of ecology and evolutionary biology at the University of California, Santa Cruz (USA), in an article published in 2007 in Nature.
Now, the scientist shows in a new study published in the Journal of Experimental Biology that these jaws allow other abilities to snowflake moray eels: grab and swallow prey, such as crustaceans, on land without water. “Most of the fish need the water to feed themselves. This is the first example of a fish that can feed on land without relying on water, ”explains Mehta.
The starry brunettes they appear to be the only species to feed on land by catching crabs on shore. “These moray eels, in particular, tend to eat hard-shelled prey, such as crustaceans,” says the biologist, who observed reports with images of moray eels emerging from the water and pouncing on crabs. “But it was not clear what happened next,” he adds.
Even fish well adapted to an amphibian lifestyle, such as mud-hopper, they need water to swallow their food. “Amphibian fish go up to the marshes and catch prey like small crabs and insects. They manage to swallow on land by breathing in water and using what they have reserved in their mouth to ingest, “Mehta details.
An unusual mechanic
Snowflake brunettes can do this without water thanks to their unusual feeding mechanics with their movable pharyngeal jaws at the throat. “Once the moray catches the prey in its oral jaws, the pharyngeal jaws latch onto it again and move it into the esophagus. This mechanical movement does not depend on water ”, clarifies the expert.
It took scientists more than five years to train seven moray eels to slide down a ramp onto a platform, grab a piece of fish, and swallow it before returning to the water.
However, it has not been an easy task to prove that snowflake moray eels can eat on land. Mehta and a team of college students took more than five years to to train seven snowflake moray eels to slide down a ramp to a platform, grab a piece of fish and swallow it before heading back into the water.
“They feel safer in the water, so at the beginning they just took the fish and went directly back to the water with it,” emphasizes the scientist, who appreciates the help received from her dedicated and enthusiastic team to work on their training. .
Thanks to his experience in the training of marine mammals, the co-author Kyle donohoe it was especially helpful. Once these fish were trained to feed on the shelf, Mehta documented this unusual feeding behavior on video.
According to the researcher, the feeding performance of young snowflake moray eels is as good on land as it is in water. “As a result, these moray eels can use very different environments in search of food,” concludes the researcher.
Rita S. Mehta et al. “Snowflake morays, Echidna nebulosa, exhibit similar feeding kinematics in terrestrial and aquatic treatments ”Journal of Experimental Biology
Rights: Creative Commons.