Scientific Illustration

rhamphotheca:

Lampreys (order Cephalaspidomorphi)

by Phillipe Janvier

Lampreys are anadromous or fresh water, eel-shaped jawless fishes. They can be readily recognized by the large, rounded sucker which surrounds their mouth and by their single “nostril” on the top of their head. The skin of lampreys is entirely naked and slimy, and their seven gill openings extend behind the eyes.

Whether marine or fresh water, lampreys always spawn and lay eggs in brooks and rivers. During most of their life (about 7 years), they are larval; then they undergo metamorphosis and become adults. Anadromous lampreys, when adult, return to the sea, where they become mature, and live there for one or two years. Then they return to rivers, reproduce and generally die.

Many lampreys are parasites. They attach on other fishes by means of their sucker, scrape their skin with their rasping tongue, and suck their blood. All lampreys, however can also feed on small invertebrates. The sucker is also for them a means to travel up stream in rivers. They use it to attach on stones to rest. Most lamprey species live in the Northern Hemisphere…

(read more: EOL)

(images: TL - Brown Trout with parasitic lamprey by USFWS; TR - Lamprey oral disc by USFWS; B - by LadyofHats)