Ken Catania Discusses Sea Predators and Neurology at ODU Lecture
As part of the Lytton J. Musselman Natural History Lecture, ODU hosted predatory biologist and neurologist Ken Catania. Catania has studied the neuroscience and behavior of numerous predators, and his talk centered on his investigation of electric eels, water shrews, tentacled snakes and star-nosed moles.
Throughout the evening, Catania focused on the hunting strategies of electric eels. He said he hoped to overturn the belief that these animals use their abilities in an unsophisticated way.
“They don’t have an electric caveman club,” Catania said.
Electric eels use a modified muscle to generate an electric current, which the eels use as a short-range taser in the water. Catania said while the high-voltage taser effect was known, he studied a more subtle, lower-voltage sensory effect, “a sort of electrical radar system,” he said.
Catania found another previously unknown behavior of electric eels. They can make potential prey convulse involuntarily to check if they’re alive. Catania noticed this after seeing strange double blasts of electricity before the eels actually attacked their prey.
Catania also discovered a never-before-seen technique used by eels to hunt tougher prey. The eels push the positive end of their electricity organ, which is near the head, toward the negative end in the tail. By curling up, the eels significantly multiply the strength of their electric field, Catania said. This sent Catania’s electricity measurements off the scale, while also exhausting the eel’s tougher prey.
A mystery which still eludes scientists is the exact molecular basis for how the mammalian sense of touch works– a cell-by-cell understanding of how the brain processes touch. Catania studies this by way of the star-nosed mole, a species local to this area, particularly in the Great Dismal Swamp. A region of the star-nosed mole’s nose, about the size of a fingertip, has up to five times more sensory fibers as the entire human hand, Catania said.
Catania made new discoveries by studying European water shrews, small swimming mice. Work with water shrews had previously lead to the discovery of direct electrical connection nerve synapses, a major step forward in neuroscience. Catania discovered star-nosed moles. When swimming, even in total darkness, water shrews can outmaneuver their aquatic prey. Water shrews have a large part of their brains devoted to processing information coming from their whiskers, resulting in an essentially instant response to feeling something around the face.
It was also discovered during Catania’s studies that water shrews are the only mammals with sense of smell while underwater. They do this by blowing bubbles through the snout, then breathing the air back in once the bubble contacts prey.
Catania also studied tentacled snakes, freshwater aquatic ambush predators that specialize in catching fish too fast for other predators. He explained that fish could escape an ambush in around 25 milliseconds, seemingly instantaneous to a human observer. Catania showed that these snakes catch these fish by predictive strikes, a phenomenon he found to be instinctual rather than learned.