Chemical Substance Found in Starfish; Research Shows How This New Find Affects the Animals’ Feeding Behavior

Past studies have shown that molecules akin to the human "love hormone" oxytocin lead the starfish to expand their stomach out of their mouths and initiate feeding.

Nonetheless, according to a Phys.org report, it was unknown which chemical substance has the power of doing the opposite and terminating behavior for feeding in these animals.

Starfish are feeding in a bizarre manner, turning their stomachs out of their mouth when coming across a sumptuous meal like oyster and mussel, and then having their chosen prey digested outside of their body.

Through the use of the common starfish Asterias Rubens for investigations, the team of researchers examined the impacts of SK/CCK-type neuropeptides, a hormone type known to hinder feeding in insects and humans.

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Starfish Belonging to 'Echinoderms'

The research team discovered that when they injected the hormones into the starfish, the animals pulled their stomachs back.

Even when the study investigators provided their starfish with a mussel, their favorite meal, they discovered that the fish tended to feed after being inoculated with the "SK/CCK-type neuropeptides."

Starfish are part of a group of animals called echinoderms. These Echinoderms occupy an extraordinary evolutionary position, functioning as a "missing link" between well-examined vertebrates and insects like the Drosophila fruit fly.

The Ohio State University describes Echinoderms as the largest phylum that has no freshwater or terrestrial constructions.

Additionally, echinoderm environments need to be marine, like in salt water, for the animal group to survive. Within marine environments, the conditions echinoderms are living can differ significantly.

This specific feature makes starfish and echinoderms such as sea urchins helpful animal models to help fill in gaps in the common insight of the manner different proteins are evolving.

Feeding Behavior

According to one of the study's lead authors and Postdoctoral Research Assistant at Queen Mary, Dr. Ana Tinoco, the unique way that starfish are feeding where they are everting their stomachs out of their mouths makes them a good model to examine chemicals that control feeding processes.

While it's already known that this type of hormone was essential for feeding, what's captivating is that the vital role of these chemical substances in feeding in other animals has been preserved in starfish despite their dramatically different behavior for feeding, absence of a brain, and extraordinary body plan.

Professor of Physiology and Neuroscience Maurice Elphick, from Neuroscience at Queen Mary said, their study findings offer new evidence that SK/CCK-type neuropeptides have an evolutionary preserved function as inhibitory regulators of feeding.

The finding of this chemical in starfish could be useful for the development of novel drugs for the treatment of eating disorders.

To achieve this, more studies need to be carried out to identify the receptor proteins' 3D structure that mediates impacts of SK/CCK-type neuropeptides in humans and other animals.

Elphick explained, with the current breakthroughs in the application of artificial intelligence to identify protein structures, the potential of utilizing basic science study like this to develop new treatment choices turn out to be more attainable.'

The study, Ancient role of sulfakinin/cholecystokinin-type signaling in inhibitory regulation of feeding processes revealed in an echinoderm, is published in ELife.

Related information about starfish stomach is shown on Oswald Beef's YouTube video below: