These Sea Sponges Use Toxic Metal As A Creative Survival Strategy – Chip Chick

by Emily Chan November 10, 2024, 11:00 am

A species of sea sponge found in the Red Sea and Indian Ocean has evolved to have a creative survival strategy.

The sea sponge is called Theonella conica, and like all other sponges, it filters the seawater around them to absorb the nutrients.

Researchers from Tel Aviv University in Israel have found that the seemingly ordinary sea sponge contains high amounts of a toxic heavy metal called molybdenum.

In other organisms, such levels of the mineral would be fatal. This discovery suggests that T. conica uses the metal as a defense mechanism to ward off predators.

“Twenty to thirty years ago, researchers from our lab collected samples of a rare sponge called Theonella conica from the coral reef of Zanzibar in the Indian Ocean and found in them a high concentration of molybdenum,” said Shani Shoham, a marine biologist from Tel Aviv University.

Molybdenum is a trace element that is necessary for both humans and animals to metabolize drugs, toxins, and sulfites. Of course, too much molybdenum is not good for us and can be lethal to other organisms.

Shoham wanted to look into whether the sponge species in the deep waters of the Gulf of Eilat had such high concentrations of molybdenum. In the Gulf of Eilat, it grows at depths of over 88 feet.

“Finding the sponge and analyzing its composition, I discovered that it contained more molybdenum than any other organism on earth: 46,793 micrograms per gram of dry weight,” Shoham said.

But how can T. conica accumulate so much of the metal and still survive? The answer lies within the sponge’s bacterial symbionts.

Sign up for Chip Chick’s newsletter and get stories like this delivered to your inbox.

See more