Microbe's toxic hunting habits could help curb massive fish kills

microbe commonly found in waterways emits a poison not just to protect itself, but to stun and immobilize the prey it plans to eat, which could help curb massive fish kills.

The researchers studied the behavior of the algal cell Karlodinium veneficum, known as a dinoflagellate and found in estuaries worldwide.

Each year, millions of dollars are spent on measures to control dinoflagellates around the globe.

This particular species is known to release a substance called karlotoxin, which is extremely damaging to the gills of fish.

Karlodinium veneficum has been known to form large algal blooms in the Chesapeake and elsewhere, triggering an immediate harmful impact on aquatic life, including fish kills.

The researchers found that K. veneficum microbes release toxins to stun and immobilize their prey prior to ingestion, probably to increase the success rate of their hunt and to promote their growth.

This significantly shifts the understanding about what permits harmful algal blooms to form and grow.

Instead of being a self-defense mechanism, the microbes' production of poison appears to be more closely related to growth through the ingestion of a "pre-packaged" food source, the cryptophyte cell.

"This new research opens the door to reducing bloom frequency and intensity by reducing the availability of its prey"As we reduce the nutrient load feeding Karlodinium's prey and bring back the bay's most prolific filter feeder, the Eastern oyster, we could essentially limit Karlodinium's ability to bloom"This is a major environmental problem, but we didn't know why these microbes were producing the toxins in the first place.
"Some people thought they were just using the toxins to scare away other predators and protect themselves.