There’s nothing better than feeding someone food without asking – but maybe waiting until they’re ready to eat and eating them whole until you get those extra calories. As Gizmodo reports, this method of feeding, known as “kleptopredation,” may be due to the fact that at least one group of mollusks prefers to eat.
In their recent study published in the journal Biology Letters, European scientists studied the eating habits of nudibranchs. Nudibranchs are soft-bodied sea snails, sometimes called “sea butterflies” for their colorful appearance. The impressive sea creatures are also effective carnivores, taking on sponges, anemones, and sometimes other nudibranchs.
For their experiment, the researchers added members of a nudibranch species called traveler hervia (Cratena peregrina) in a tank with one of their favorites: hydroids, relative of slippery. Plankton was also present to eat the waters. When given a choice between the empty-stomached hydroids and hydroids that had just been eaten or were in the middle of eating plankton, the nudibranchs selected the prey with good nutrition in 14 out of the 25 trials. According to the study’s authors, plankton can make up at least half of the nudibranch diet in this way even if it is indirectly preyed upon. This means that a nudibranch interaction with a plankton-loving cnidarian may go beyond the basic predator-predator relationship.
Although the choice of nudibranchs for hydroids that had eaten plankton was not random, that does not automatically mean that it is a case of kleptopredation. The sea snails may have chosen the larger-looking prey, or they may have gone after the waters that had just been fed because of the sting cells that the cnidarian use for hunting on the sea. wear and so less harm.
If more research supports the theory that the animals focus on full predation before they have a chance to digest, that would add the unique predation approach to the already impressive roster of nudibranch abilities.
[h/t Gizmodo]