CEPHALASPIDOMORPHI Description: 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 spaw and lay eggs in brooks and rivers. 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 upstreams in rivers. Examples: 1. Petromyzonmarinus - Sea Lamprey 2. Ichthyomyzon bdellium - Ohio Lamprey