A Little Help from a Friend: 5 Symbiotic Marine Animal Relationships

One of life's most fundamental truths is that there are moments when collaboration outweighs conflict. The 'symbiotic interactions' that have grown between different animals in marine ecosystems are proof that the same concept is true beneath the water. Through the process of evolution, certain aquatic creatures have discovered that cooperating with others will boost their chances of surviving in a dangerous fish-eat-fish environment.

Symbiosis is a term used in science to describe a tight, long-term relationship between two organisms where at least one partner benefits in some way. Both marine and land creatures engage in symbiotic interactions. There are three primary sorts of these connections:

  1. Mutualism—explains a partnership where both parties gain from their interaction.
  2. Commensalism—a partnership where one partner reaps the rewards while the other is unaffected.
  3. Parasitism—an unhealthy partnership in which one party gains at the expense of the other.

Marine habitats contain a vast number of symbiotic connections. Here is a list of some of the ones that scuba divers have seen most frequently.

Clownfish and Anemones

This is a friendship for the ages. Photo Credit: NOAA

A prime example of mutualism, where two creatures gain from cooperating, is the relationship between clownfish and sea anemones. Clownfish live among the sea anemone's venomous tendrils, which offer them cover, safety, and a place to hide from potential predators. Clownfish are protected in the anemone's embrace because they have a biological resistance to the sting. In exchange, the anemone reaps rewards by eating the cowfish's leftovers and any food bits that inevitably fall to the ground while the clownfish eats. The continual aeration produced by the cowfish's movement helps anemones stay vivid.

Barnacles and Whales

Barnacles on a gray whale in Hare Eye Lagoon, Mexico. Photo Credit: Ken-Ichi Ueda

Barnacles and whales, primarily humpback whales, have a wonderful working relationship, with the barnacles benefiting greatly from the whales' bellies or backs. A filter feeder, barnacles ingest plankton that passes via feather-like appendages that extend through holes in their shells. They travel from meal to meal by hopping on a whale's body as it moves through plankton-rich waters, being carried about like royalty. Additionally, since only the most daring predators are likely to attack a whale, protection from predators is a benefit. Since they can handle the weight of thousands of barnacles at once, whales are largely unharmed by this process. A symbiotic commensal interaction between whales and barnacles is one example.

Pistol Shrimp and Gobies

A seeing-eye fish Photo Credit: Klaus Stiefel

Despite being essentially blind, the tiny pistol shrimp has asked the bottom-dwelling goby to serve as its eyes and ears. The pistol shrimp spends its days seeking for food by creating tiny tunnels in the sandy ocean floor. The result is that the pistol shrimp makes holes that are precisely the right size to offer a goby a place to rest and some protection. The pistol shrimp gives the goby free rent-free access to the holes it digs in exchange for the goby doing one task: acting as watchman. The goby flicks its tail numerous times to warn the shrimp of impending danger when a predatory fish approaches. The shrimp and goby withdraw well into their burrows to wait out the attack.

Decorator Crabs and Sea Sponges/Anemones

A decorator crab shows its style in the latest 2017 fashion. Photo Credit: Bernard Dupont/Wikimedia Commons

Decorator crabs affix elements from their surroundings on their shells to assist them blend in with their surroundings and use the time-tested technique of camouflage to help them survive. The clever thing is that they also incorporate real animals, such as sea sponges and anemones, in addition to non-living ones. The decorator crab cuts off bits of sponge and anemone to add to its shell, gaining either a useful weapon (in the case of a marine sponge) or a piece of camouflage (in the case of a poisonous anemone). Like a barnacle, the sea sponge and anemone benefit from being transferred to other feeding grounds while continuing to survive on the decorator crab's back.

Sharks and Pilot Fish

An oceanic whitetip shark and a group of pilot fish swimming at the Elphinstone Reef in the Red Sea, Egypt. Photo Credit: Oldak Quill

Making the strongest of all allies is part of the pilot fish's survival strategy. A shark will frequently be spotted cruising the sea in search of prey as the striped fish swims beneath it. The crucial task of ridding the shark's skin of parasites is carried out by the pilot fish, and in exchange, the shark serves as a protector. Because it is aware of the advantages of being spotless, the ocean's top predator exhibits incredible discipline by avoiding the pilot fish.


Author: Ryan Patrick Jones

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