Context: A further example is the goby fish, which sometimes lives together with a shrimp. The shrimp digs and cleans up a burrow in the sand in which both the shrimp and the goby fish live. The shrimp is almost blind, leaving it vulnerable to predators when outside its burrow. In case of danger the goby fish touches the shrimp with its tail to warn it. When that happens both the shrimp and goby fish quickly retreat into the burrow. Different species of gobies (Elacatinus spp.) also exhibit mutualistic behavior through cleaning up ectoparasites in other fish.

Question: What species does this shrimp have a relationship with?
Answer: the goby fish

Question: What part of the fish is used to signal danger?
Answer: its tail

Question: What organism digs a burrow in the sand then touches the goby fish with its tail?
Answer: Unanswerable

Question: What is the species of goby that both lives with a shrimp and cleans up ectoparasites on other fish?
Answer: Unanswerable

Question: What behavior does the goby exhibit when it does not live with the shrimp?
Answer: Unanswerable

Question: What behavior does the shrimp exhibit when it does not live with the goby?
Answer: Unanswerable

Question: When a goby fish goes blind what does it become vulnerable to?
Answer: Unanswerable