This ancient jawless fish is seeing for the first time after recently metamorphosing to resemble its more familiar adult form. Juvenile Pacific lamprey (Lampetra tridentate) begin life appearing more like a worm than a fish. As larval lampreys or “ammocoetes” they lack eyes and fins, and spend 5-7 years buried tail first in the river substrate, filter feeding by mouth. Once they reach a length of around 14-16 cm they begin a radical change in physiology and physical appearance. They become silvery, and develop long dorsal fins, large eyes, and a strong sucking mouth with lateral tooth plates. The newly transformed lamprey swim downstream to the ocean where they will begin a novel life as marine predators. Check out our previous Pacific Lamprey post for additional photos and life history information.
Photo source: FISHBIO