Question: which one of the following is true fish?
Answer: Among Jellyfish, Starfish, Dogfish and Silverfish, dogfish is a true fish. Jellyfish cannot be classified as a fish because it does not fulfill the criteria of being called a fish. A fish must have gills, fins and a vertebra, all of which a jellyfish lacks. Starfish also falls in the same criteria as a jelly fish.