Toxic Blooms Aid Predation

a shoreline shores water with an orange algae bloom layer before blue body of water

Biological Strategy

Dinoflagellates

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Image: Jeri Cusimano/ Washington State Department of Ecology / Flickr / CC BY NC - Creative Commons Attribution + Noncommercial

Capture, Absorb, or Filter Organisms

Many living systems must secure organisms for food. But just as one living system must capture its prey to survive, its prey must escape to survive. This results in capture and avoidance strategies that include trickery, speed, poisons, constructed traps, and more. For example, a carnivorous plant called the pitcher plant has leaves formed into a tube that collect water. Long, slippery hairs within the tube face downward. When insects enter the tube seeking nectar, they lose their footing and slide inside, unable to climb out and escape being eaten and digested by the plant.

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Protists

Kingdom Protista (“the very first”): slime molds, giant kelp, red and brown algae

Protists are a numerous, diverse group of organisms that, in the simplest definition, are defined by what they are not. Protists are not plants, animals, fungi, or bacteria. Some protists, like Plasmodium, are harmful parasites that cause malaria. While many are small, obscure, and go unnoticed, others are important foodstuffs. The largest protist in the world, giant kelp (Macrocystis pyrifera), is utilized by humans and marine species for food and shelter.

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Toxic blooms produced by some dinoflagellates may aid predation by immobilizing their algal prey.

“The toxins produced by some algal blooms may have evolved to give
predatory algae an advantage when it comes to capturing their prey,
researchers say…

“Single-celled algae called dinoflagellates are one of the organisms
responsible for harmful algal blooms that poison shellfish and leave
fish floating belly-up. Because the toxins are energetically costly to
make, biologists have long wondered whether they are more than just a
way to defend algae from getting eaten or preventing competitors from
moving in on their space. Although many dinoflagellates can survive
through alone, some species are able to grow twice as
fast by preying on other algae — and it is this feeding mechanism that
is now thought to be aided by the production of toxins…

“Toxic strains of K. veneficum immediately
caused the prey to slow down by more than 50%, and nearly doubled the
proportion of immobile algae in the water relative to non-toxic strains.
After 5 hours, more than 90% of the prey were immobile…Notably, K. veneficum
also slows down in the presence of prey, which may be a means of
staying within the toxic cloud to aid predation.” (Borrell 2010)

http://www.pnas.org/content/107/5/2082.abstract
http://www.nature.com/news/2010/100111/full/news.2010.5.html?s=news_rss#B2

Last Updated August 18, 2016

References

Harmful algae stun their prey

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Reference

Journal article

A dinoflagellate exploits toxins to immobilize prey prior to ingestion

Proceedings of the National Academy of Sciences | 20/01/2010 | J. Sheng, E. Malkiel, J. Katz, J. E. Adolf, A. R. Place

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