Sea Lamprey (Petromyzon marinus)
AKA: Lamprey eel (incorrectly)
Identifying characteristics: Small snake-like body with sucker-like mouth and concentric rings of teeth and file-like tongue. Juveniles tend to be a mottled blue-gray while adults are mottled brown/black. The skin is smooth with no scales. The dorsal fin is divided into two distinct lobes. A row of 7 gill holes is visible just behind the head.
Size: Juveniles range from 6 to 24 inches, while adults range from 14 to 32 inches in length.
New York State record: none kept.
Habitat: Like many Salmon, the sea lamprey will live most of its mature life in open ocean or large lakes and return to inland stream to spawn. Larvae live in their natal streams for years. Lampreys can tolerate a wide range of conditions. Larvae need productive streams for filter-feeding. Mature lampreys will need suitable prey.
General range: The landlocked form can be found in Lake Ontario and Lake Erie, Lake Chaplain, Oneida, Cayuga and Seneca Lakes. Ocean dwelling lampreys can be found spawning up the Hudson and its tributaries.
Food: Larvae dig burrows and filter feed. Juveniles are parasitic and will attach themselves to a large lake or ocean fish with their sucker mouth and sharp teeth. They then tear away the fish’s skin and scales and begin feeding on its blood and body fluids. Lampreys secrete an anti-coagulant to prevent the host-fish’s blood from clotting. Blood loss and infection often kill the host fish, and the lamprey detaches and moves on.
Recommended baiting: Dip netting is often used to catch eels during spawning, when they gather in great numbers.
Predators: Larger predatory fish. Humans.
Stocked? No. Invasive.
Reproduction: Spawning occurs in late May/early June. Males begin excavating nests and wait for a female to come and attach herself to a nearby rock. Spawning pairs induce more pairs to join, with as many as nine pairs sharing a nest. Eggs are deposited in the depression. Adults die shortly after spawning. Larvae drift downstream to calmer waters and live for years, filter feeding in muddy pools before they turn into adults.
Nesting: Nests are excavated depressions in stony creek beds, upstream from a riffle. Since the spawning habits of the Silver Lamprey are similar, both species often share the same nests.
Other Info.: Although considered a tasty meal in many regions outside of the United States, Sea Lampreys are regarded as pests here. Although native to ocean-connected river systems, they have been accidentally introduced to our larger freshwater lakes such as Lake Ontario, Erie and the larger Finger Lakes. There they have greatly reduced the numbers of top predator fish, which in turn opened up the opportunity for fast-breeding feeder fish, such as the alewife, to overpopulate and shift the food chain.