Carnivorous “death ball” sponge that traps prey with microscopic hooks discovered in Southern Ocean

Scientists working in the Southern Ocean have identified a strange deep-sea sponge that behaves in a way most people wouldn’t expect from a simple marine organism. The sponge, nicknamed a “death ball,” appears to capture small prey using tiny hook-like structures on its surface. The discovery adds another example of how little we still know about deep ocean ecosystems.

The find is especially interesting because sponges are usually seen as passive filter feeders. Instead of actively hunting, they typically absorb particles from the water. This newly observed species challenges that simple view by suggesting it may be capable of trapping and holding small organisms that come into contact with its surface.

How the “death ball” structure works

Researchers believe the sponge’s outer structure is covered in microscopic hooks or spines that can latch onto tiny prey drifting through the water. Once trapped, the organism is thought to be slowly broken down and absorbed, similar to how other sponges process nutrients, but with a more active capture step involved.

The overall shape has been described as rounded and dense, which may help maximize contact with passing organisms in the deep sea. In an environment where food is limited, even small advantages in capturing nutrients can make a big difference for survival.

Why this discovery matters

Finding a carnivorous-leaning sponge changes how scientists think about deep-sea life. The Southern Ocean is one of the least explored regions on Earth, and many organisms there have evolved unusual survival strategies due to extreme cold, darkness, and limited food supply.

This sponge adds to a growing list of deep-sea species that blur the line between passive and active feeding. It also raises questions about how many other organisms in similar environments might have evolved unexpected hunting or trapping methods that haven’t been observed yet.

What scientists are still trying to understand

Researchers are still studying how the sponge’s trapping mechanism actually works in detail, including whether it actively moves or relies entirely on water currents. There’s also ongoing interest in what kinds of organisms it captures and how efficient the process really is.

Because deep-sea research is difficult and expensive, discoveries like this often come from limited samples. That means scientists are cautious about drawing conclusions too quickly, even when early observations suggest unusual behavior.