Long-spined sea urchins
Long-spined sea urchins (National Marine Sanctuaries/CC BY 4.0)

Transglobal Spread of a Sea Urchin Parasite

The study identified the parasite that devastated 95 percent of long-spined sea urchins in affected areas in the Caribbean Sea two years ago. It burrows into the tissue of the sea urchins and triggers abnormal behaviour. The urchins droop and lose their ability to control their tube feet, which are crucial for movement. They lose their spines, then tissue necrosis sets in, leading to the death of the sea urchins.

Brittle star

Brittle stars can learn without a brain

Instead of a brain or eyes, brittle stars have nerve cords that run down each of their five arms, which join to form a nerve ring near the mouth. 

Nonetheless, according to a recent study, they possess the ability to learn by association, which involves making an association with different stimuli via a process called classical conditioning (like Pavlov’s dogs or us learning not to touch a pot of boiling water after we had been scalded before.

Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines
Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines

Sea urchins see with their whole body

According to a study that appeared in the Journal Proceedings of the National Academy of Sciences, new research has indicated that sea urchins may use the entire surfaces of their bodies—from the ends of their "feet" to the tips of their spines—as huge eyes. Scientists have long known that marine invertebrates react to light without any obvious eye-like structures, raising the question of how the animals see.

Echinoderms are a renewable resource with an economic value due to their increasing demand as food and/or source of bioactive molecules exerting antitumor, antiviral, anticoagulant, antioxidant, and antimicrobial activities.

Sea Urchin Could Help Cure Diseases

A purple sea urchin has 70 percent of its genes in common with humans, including genes associated with such diseases as Huntington’s, Parkinson’s, Alzheimer’s and muscular dystrophy.

There are roughly 100 human disease genes in the sea urchin genome.

Researchers said they believe similarities in the genes of sea urchins could one day help them better understand how the human immune system works.