![](http://image.absoluteastronomy.com/images//topicimages/noimage.gif)
Pacific lamprey
Encyclopedia
The Pacific lamprey is an anadromous parasitic lamprey
from the Pacific
Coast of North America
and Asia
. It is also known as the three tooth lamprey and tridentate lamprey.
, swim out to the ocean
where they feed as a juvenile, and then mature and return to freshwater as an adult to reproduce). Pacific lampreys are semelparous (meaning they die after reproducing once during their lifetime).
Although the adult and juvenile stages are more noticeable, lamprey spend the majority of their lives as larvae (ammocoetes). Ammocoetes live in fresh water for many years (usually 3-7 years, but at least one species has been recorded for +17 years). Ammocoetes are filter feeders who draw overlying water into burrows they dig into soft bottom substrates. After the larval period the ammocoetes undergo metamorphosis and take on the juvenile/adult body morphology. Juveniles/adults have a jawless sucker-like mouth that allows them to become parasitic
on other fish. The adults live at least 1-2 years in the ocean and then return to fresh water to spawn
. It is not well understood if Pacific lamprey return to their natal streams or seek spawning areas based on other cues. They typically spawn in similar habitat to Pacific salmon
and trout
. Lamprey construct a nest (redd) in small gravel and females can lay over 100,000 eggs
, which are fertilized
externally by the male. After spawning the adults usually die within 4 days. Also, like salmon, the Pacific lamprey does not feed while migrating
to spawn.
food
for Native American
tribes in the Columbia River
basin. Pacific lamprey numbers in the Columbia River
have greatly declined with the construction of the Columbia River hydro-power system. Almost no harvest opportunity for Native Americans remains in the Columbia River and its tributaries except for a small annual harvest at Willamette Falls
on the Willamette River
(tributary to the Columbia River).
Lamprey
Lampreys are a family of jawless fish, whose adults are characterized by a toothed, funnel-like sucking mouth. Translated from an admixture of Latin and Greek, lamprey means stone lickers...
from the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
Coast of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. It is also known as the three tooth lamprey and tridentate lamprey.
Biology
Pacific lamprey are dark blue or brown in color and grow to about 30 inches (76 cm) as adults. They are anadromous (meaning they are born in fresh waterFresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
, swim out to the ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
where they feed as a juvenile, and then mature and return to freshwater as an adult to reproduce). Pacific lampreys are semelparous (meaning they die after reproducing once during their lifetime).
Although the adult and juvenile stages are more noticeable, lamprey spend the majority of their lives as larvae (ammocoetes). Ammocoetes live in fresh water for many years (usually 3-7 years, but at least one species has been recorded for +17 years). Ammocoetes are filter feeders who draw overlying water into burrows they dig into soft bottom substrates. After the larval period the ammocoetes undergo metamorphosis and take on the juvenile/adult body morphology. Juveniles/adults have a jawless sucker-like mouth that allows them to become parasitic
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
on other fish. The adults live at least 1-2 years in the ocean and then return to fresh water to spawn
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
. It is not well understood if Pacific lamprey return to their natal streams or seek spawning areas based on other cues. They typically spawn in similar habitat to Pacific salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
and trout
Trout
Trout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...
. Lamprey construct a nest (redd) in small gravel and females can lay over 100,000 eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
, which are fertilized
Fertilisation
Fertilisation is the fusion of gametes to produce a new organism. In animals, the process involves the fusion of an ovum with a sperm, which eventually leads to the development of an embryo...
externally by the male. After spawning the adults usually die within 4 days. Also, like salmon, the Pacific lamprey does not feed while migrating
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
to spawn.
As Food
Pacific lamprey are an important ceremonialCeremony
A ceremony is an event of ritual significance, performed on a special occasion. The word may be of Etruscan origin.-Ceremonial occasions:A ceremony may mark a rite of passage in a human life, marking the significance of, for example:* birth...
food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
for Native American
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
tribes in the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
basin. Pacific lamprey numbers in the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
have greatly declined with the construction of the Columbia River hydro-power system. Almost no harvest opportunity for Native Americans remains in the Columbia River and its tributaries except for a small annual harvest at Willamette Falls
Willamette Falls
The Willamette Falls is a natural waterfall on the Willamette River between Oregon City and West Linn, Oregon, in the United States. It is the largest waterfall in the Pacific Northwest and the eighteenth largest in the world by water volume. Horseshoe in shape, it is wide and high with a flow...
on the Willamette River
Willamette River
The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is long, lying entirely in northwestern Oregon in the United States...
(tributary to the Columbia River).