Symbiotic Interactions

When one organism is harmed and one organism benefits, it is called:

• mutualism

• commensalism

• parasitism

When both organisms benefit from a relationship it is called:

• mutualism

• commensalism

• parasitism

When one organism benefits and the other is unharmed, that relationship it is called:

• mutualism

• commensalism

• parasitism

A pearlfish spends the day inside the intestines of a sea cucumber. The fish emerges from the sea cucumber at night to feed on small crustaceans. The pearlfish gets a safe place to live. The sea cucumber does not gain anything from the relationship, nor is it harmed.

• parasitism

• mutualism

• commensalism

A cymothoid isopod lives inside the mouth of a snapper fish. The isopod severs blood vessels in the fish’s tongue, causing the tongue to atrophy and degenerate. The isopod then hooks its legs to the base of the fish’s tongue, essentially replacing the tongue. The isopod stays there for the rest of its life, feeding on blood, mucus, and stray pieces of food from the fish.

• parasitism

• mutualism

• commensalism

Tags

NGSS.MS-LS2-2

NGSS.MS-LS2-4

A boxer crab carries a pair of small anemones in its claws. When approached by a predator, the crab waves the stinging tentacles of the anemones to deter the predator. The anemones benefit from the small particles of food dropped by the crab during feeding.

• parasitism

• mutualism

• commensalism

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-3

An alpheid shrimp digs and maintains a deep burrow. While underground, the shrimp is safe. Above ground, it is vulnerable to predators. A goby fish lives in the burrow with the shrimp. The goby fish sits at the entrance, keeping watch for predators, and signals the shrimp with a flick of its tail when it is safe to come out. Or, if a predator swims by, the goby darts into the burrow and the shrimp retreats further inside. These two animals are completely dependent on each other—the goby benefits by getting a burrow to live in and the shrimp knows when predators are near.

• parasitism

• mutualism

• commensalism

Tags

NGSS.MS-LS2-2

Some species of barnacles attach themselves to sea turtles or whales. As the whales or sea turtles travel, the barnacles gain access to food in nutrient-rich waters. Their host neither benefits nor is harmed by its riders.

• parasitism

• mutualism

• commensalism

Tags

NGSS.MS-LS2-2

A tapeworm needs to eat food that is already digested, so it lives in the intestines of a dogfish shark and derives nourishment from the shark. As a result of the tapeworm infestation, the shark is weakened and more vulnerable to disease and predation.

• parasitism

• mutualism

• commensalism

Tags

NGSS.MS-LS2-3