Researchers have found that a type of predatory sea slug that usually isn’t picky when it comes to what it eats has more complex cognitive abilities than previously thought, allowing it to learn the warning cues of dangerous prey and thereby avoid them in the future. The research appears in the Journal of Experimental Biology.
Pleurobranchaea californica is a deep-water species of sea slug found off the west coast of the United States. It has a relatively simple neural circuitry and set of behaviors. It is a generalist feeder, meaning, as University of Illinois professor of molecular and integrative physiology and leader of the study Rhanor Gillette put it, that members of this species “seem to try anything once.”
Another sea slug species, Flabellina iodinea, commonly known as the Spanish shawl because of the orange outgrowths called cerata that cover its purple back, also lives on the west coast. Unlike Pleurobranchaea, however, the Spanish shawl eats only one type of food, an animal called Eudendrium ramosum.
According to Gillette, the Spanish shawl digests all of the Eudendrium except for its embryonic, developing stinging cells. The Spanish shawl instead transports these stinging cells to its own cerata where they mature, thereby co-opting its victim’s body parts for its own defense.
The story of Gillette’s Pleurobranchaea–Flabellina research began with a happy accident that involved showing a lab visitor Pleurobranchaea‘s penchant for predation.
“I had a Pleurobranchaea in a small aquarium that we were about to do a physiological experiment with, and my supplier from Monterey had just sent me these beautiful Spanish shawls,” Gillette said. “So I said to the visitor, ‘Would you like to seePleurobranchaea eat another animal?'”
Gillette placed the Spanish shawl into the aquarium. The Pleurobranchaeaapproached, smelled, and bit the purple and orange newcomer. However, theFlabellina‘s cerata stung the Pleurobranchaea, the Spanish shawl was rejected and left to do her typical “flamenco dance of escape,” and Pleurobranchaea also managed to escape with an avoidance turn.
Read more at: Phys.org