Apr 06, 2021 17:00:00

Starfish brothers turned out to 'dance and eat' each other from an early age

A study from the

University of William and Mary found that a starfish larva, Asterias forbesi, which inhabits the northwestern Atlantic Ocean and shallow waters of the Caribbean Sea, eats other individuals that are almost the same size as itself. .. Cannibalism itself is a behavior that is widely seen in nature, but it seems that it has not been known until now that starfish that have grown to some extent cause cannibalism.

Cannibalism of newly metamorphosed juvenile sea stars --Brocco French ---- Ecology --Wiley Online Library
https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3352

You didn't see this on'Spongebob': Cannibal sea star babies | William & Mary
https://www.wm.edu/news/stories/2021/you-didnt-see-this-on-spongebob-cannibal-sea-star-babies.php

Hungry baby sea stars eat each other in unexpected case of underwater cannibalism | Live Science
https://www.livescience.com/young-sea-stars-eat-their-siblings.html

According to Carina Brocco French and Jonathan Allen of the Department of Biology at the University of William and Mary, the Asterias forbesi larvae that have turned from eggs are plankton shaped like small spaceships for about a month. He said that he would live in the sea. Then, when it grows to a certain extent, it transforms into a juvenile with five arms, which is typical of a starfish, and begins to live on the seabed.

Brocco French and colleagues initially bred Asterias for besi larvae to study how starfish larvae respond to predators such as crabs. However, the experiment was canceled because the juveniles, only four days after the metamorphosis, began to dance and eat each other, and the experiment was shifted to the experiment of observing the cannibalism of starfish. Until now, it has been known that larvae that have settled on the seabed may eat small larvae that happen to sink, but it is known that larvae of almost the same size cannibalize each other. did not.

Regarding the cannibalism of young starfish, Brocco French said, 'They do not put what they eat in their mouths, but take their stomachs out of their mouths to digest, decompose and then absorb them. The stomach that comes out of the mouth is called the 'stomach of the larva'. '

by Neil DeMaster

Female starfish lay 5 to 10 million eggs at a time, so fierce competition for food is inevitable without cannibalism. Therefore, Allen and his colleagues think that they may be trying to survive by eating together with their brothers.

About cannibalism, Allen said, 'We humans think it's horrible to eat each other by convention, but it can be rather welcome behavior in the animal kingdom, so it's more than we think. Cannibalism may be a common strategy. '