Silver Lamprey - Identification

Identification

The silver lamprey is an eel-like fish with an attenuate body composed of 49–52 clearly defined segments (i.e. myomeres, between the last gill slit and the anus). Silver lampreys possess a cartilaginous skeleton, and adults generally grow to a length of 12 inches and are silvery or bluish in color when spawning. Prior to spawning adults are often a dull brown or tan color. The dorsal fin is continuous, though it may be notched. The mouth is a jawless, sucking disc, with unicuspid teeth arranged in circular rows and is in the inferior position. When expanded, the mouth is wider than the lamprey's body. The lamprey's gills are arranged in a straight line immediately behind the eye, and a single nostril is located between the eyes. Larvae are a brown to tan all over have no eyes (instead they have eyespots) and are called ammocoetes. They also have seven gill openings and do not have any paired fins, they have only a long continuous fin runs from the dorsal to the ventral side. Ammocoetes also have no teeth and instead have an oral hood which houses skin extensions that help them filter particles out of the water as they draw it into their oral cavity.