Clownfish and Anemone {a·nem·o·ne}

Clownfish benefit by sheltering themselves and their eggs from dangers in the stinging tentacles of the anemone. They also feed on any of the predatory anemone’s leftovers.

Their constant swimming about and fin-fanning also helps circulate water to the inner tentacles, refreshing oxygen and mineral supplies.

The anemone benefits as the clownfish removes parasites and provides nutrients from its leftovers and waste.

Pistol Shrimp and Gobi

Pistol shrimp (Alpheus spp.) and gobies (Amblyeleotris spp.) are best fish friends, and room together as part of another mutualistic relationship.

True companions, the strong-armed shrimp digs the hole, and the larger goby protects it.

The shrimp relies on the goby’s good eyesight to fend off threats, and repays his friend with a safe place to hide and sleep.

Boxer Crab Fashion

Sometimes the crabs will even swing their pom-poms back and forth to try and intimidate potential predators.

Should the crab lose one of its anemones, it unceremoniously rips the other in two, since anemones can re-generate after bisection.

In this mutualistic relationship, the crabs add some extra punch to their claws with the anemone’s stingers,

Cleaning Fish

Cleaner fishes (a subset of gobies, wrasses, and shrimp) set up shop near coral reefs, and take all sorts of walk-in patients, with which they have a mutualistic relationship.

The larger animals (or divers) swim up and allow the cleaners to pick out parasites, dead skin cells, and mucus from their bodies.

The cleaner fish benefit from the free, low-risk meal, and from the temporary protection of associating with more intimidating fish. Watch these guys do their job here

Whales and Barnacles

The relationship between whale and barnacle is yet another example of commensalism.

The barnacle reaps great rewards by attaching itself to a whale because of its filter-feeding nature.