Symbiosis in the Ocean

A pearlfish spends the day inside the intestines of a sea cucumber. The fish emerges at night to feed on small crustaceans

• commensalism

• mutualism

• parasitism

Answer explanation

Correct- the cucumber's intestines are harmed by the pearlfish

An isopod lives inside the mouth of a snapper. The isopod severs blood vessels in the fish’s tongue. The isopod hooks its parapods (legs) to the base of the tongue and remains there for life feeding on blood, mucous and stray pieces of food

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct- the key word here was "sever"

A boxer crab carries a pair of small anemones on its chelipeds (claws). The crab waves its claws to deter predators and the anemones get food dropped by the crab during feeding

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, both species benefit each other

An alpheid shrimp digs and maintains a deep burrow. A goby fish lives in the burrow with the shrimp. The goby keeps watch at the entrance and signals with a flick of its tail when it is safe for the shrimp to come out.

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, both look out for each other

Corals feed off the byproducts of zooxanthellae- a microscopic algae living within their own tissue. The photosynthetic activity of the algae is vital to the survival of the coral animals and powers the building of their calcareous skeletons. The algae is protected by the hard coral

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, they rely on each other for survival

Some species of barnacles attach themselves to sea turtles or whales. The barnacle travel and gains access to food without harming its host

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, "without harming" the host

A tapeworm needs to eat food that is already digested. Many dogfish shark are infested with tapeworms, becoming more vulnerable to disease and predation

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, the key word was "infestation"

Imperial shrimp have been observed hopping on and off traveling sea cucumbers to feed

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, the cucumber didn't get any gas money

The siboglinid tube worm found at deep-sea hydrothermal vents and cold seeps has no digestive tract. It relies on internal bacteria to oxidize hydrogen sulfide or methane for the worm.

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, the bacteria get a free place to live.

Some shrimp and crabs live and capture food from within the tentacles of giant anemones

• Commensalism

• Mutualism

• Parasitism

Answer explanation

Correct, the crabs and shrimp benefit the anemone by detering predators.