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| Sea Slugs |
Sea slugs or Nudibranchs, with their varied colours, shapes and sizes, are
significantly more fascinating than terrestrial slugs. The bright colours worn
by slugs in the ocean indicate, to their predators, that they are armed with
potent toxins. This is just one of their many defence mechanisms. Some slugs
are capable of blending into their backgrounds so well that they are barely
visible to their predators. Some bioluminescent slugs warn their predators of
their toxicity with a hypnotic display of blinking lights. Some change their
behaviour to avoid predators by becoming nocturnal and or even staying dormant
most of the time, only swimming for short periods when disturbed. The most remarkable
defence mechanism of slugs is shown only by a few species of the Aeolids group.
These slugs actually steal the defence mechanisms of their predators. Some
organisms like sea anemones and jellyfish have special stinging cells along
their tentacles. These stinging cells, when triggered, shoot out tiny
spear-like structures called Nematocysts, that can attack either their prey or
predators. When sea slugs are attacked by creatures with these stinging cells, the
chemicals in their slime keep the nematocysts from liberating. This makes sure
the slugs don’t get stung. They then ingest the stinging cells with unreleased
nematocysts. Some of these cells are digested and excreted out while the
younger, immature nematocysts are stored for later use, in pouches called Cnidosacs.
When these Aeolid slugs are provoked, they use the pilfered stinging
nematocysts to protect themselves from predators. One of the most well-known strategies
in any kind of conflict is to take advantage of the enemy’s weakness. What these
Aeolid sea slugs have managed to do is use their enemy’s strength to their
benefit.
