Clam throws insulin into water to paralyze trapped by hypoglycemia

Research reveals prey capture as the unprecedented role of the substance. Insulin helps mollusks paralyze whole shoals of fish.

Scientists have found that a clam species has a peculiar strategy for capturing its prey. These animals release insulin into the water to cause hypoglycemia in shoals of small fish. This makes them slow and disoriented, making them easier targets.

The species that developed this strategy, Conus geographus, moves slowly, so it relies on its poison to hunt for prey. But until then, it was not imagined that insulin was part of this process. The mollusk was believed to fire a mixture of immobilizing toxins through a fake mouth. When the fish were hit and stopped moving, they were swallowed by the clam.

Images show two species of mollusk, the Conus geographus (left) and Tulip Conus (right) meaning catching fish; they release insulin into the water to cause hypoglycemia in their prey, making them slower

Clam Conus geographus uses insulin to paralyze prey

Researchers at the University of Utah in the United States wanted to discover the mechanism that made clam fangs slow with contact with its poison. By analyzing the proteins produced in the gland of the Conus geographus, found two that were very similar to the hormone insulin, which controls blood sugar.

It was found that the species Tulip Conus It also uses the same hunting strategy. "This is a unique type of insulin. It is shorter than any other type of insulin described in any animal," says Baldomero M. Oliveira, a professor at the University of Utah and one of the study's authors.

To test whether this insulin was really hunting-assisting, scientists synthesized in the laboratory the same substance produced by mollusks and tested its effects on zebrafish. The substance caused glucose levels to drop and hampered fish movements.

The results suggest that insulin helps mollusks paralyze whole shoals of fish through hypoglycemic shock, or insulin shock.

According to the authors of the study, published Monday, January 19, 2015 in the Proceedings of the National Academy of Sciences, the results reveal a previously unknown role of insulin as a way to capture prey. Study the insulin produced by Conus geographus may help understand the action of insulin on the human body, according to the researchers.