An overview of several aspects of lamprey life history. The lamprey is a very primitive, eel-like fish that inhabits both fresh and salt waters around the world. Canada is home to numerous species, including one that is endemic to the country ( Vancouver Lamprey, Lampetra macrostoma). This paper will discuss the ecology of these fish, especially the reproductive and feeding ecologies which are quite fascinating and unique. As well, each species found in Canada will be discussed, including such aspects as distribution and identification. Finally, the environmental impacts of lampreys, specifically the Sea Lamprey (Petromyzon marinus) will be discussed, since these are extremely important concerns for fisheries and ecologists in the Great Lakes.

References:

Beamish, F.W.H. 1980. Biology of the North American anadramous Sea Lamprey, Petromyzon marinus. Canadian Journal of Fisheries and Aquatic Sciences 37:1924-1943.

A summary of the life history of the Sea Lamprey (Petromyzon marinus), which is found along the Atlantic coast of North America, as well as inland into the Great Lakes where is has been accidentally introduced. The study follows the life history of this parasitic fish from the freshwater juvenile phase, called an ammocoete, to the saltwater, where the adult fish spends most of its life, and back to freshwater streams where spawning occurs. The study mostly focuses on the juvenile ammocoete form, and includes aspects such as feeding ecology, predation on, mortality of, and, in older juveniles, marine distribution of these young.
 

Beamish, R.J. 1980. Adult biology of the River Lamprey (Lampetra ayresi) and the Pacific Lamprey (Lampetra tridentata) from the Pacific coast of Canada. Canadian Journal of Fisheries and Aquatic Sciences 37:1906-1923.

A summary of the life histories of two of Canada’s anadramous lamprey species: the River Lamprey (Lampetra ayresi) and the Pacific Lamprey (Lampetra tridentata), both from coastal British Columbia. Being anadramous and fairly large in size, both species are parasitic on coastal saltwater fish, whereas other smaller, freshwater species are not parasitic at all. The study is not concerned with the long juvenile phase of these fish, called an ammocoete, which remains buried in the gravel of streams until it is metamorphosed into the eel-like adult. The study follows the metamorphosed adults throughout their life history, from freshwater streams to saltwater, and back to streams to spawn. The distribution, feeding habits, predation on, and movements while in saltwater are all discussed.
 

Dahl, F.H. and R.B.McDonald. 1980. Effects of control of the Sea Lamprey (Petromyzon marinus) on migratory and resident fish populations. Canadian Journal of Fisheries and Aquatic Sciences 37:1886-1894.

The study looks at the effects of three control methods: i) mechanical barriers (such as weirs), ii) electrical barriers, and iii) addition of chemicals called lampricides to streams, all designed to stop the introduced Sea Lamprey (Petromyzon marinus) from spawning in native streams. The effectiveness of each method is discussed but the main focus is on the effects on local, native fish populations. According to the paper, the only example of a native fish species being affected by these methods is the near extinction of the Stonecat (Noturus flavus) from streams in the southwest corner of Lake Superior due to chemicals added to the streams.

DuBois, R.B. and W.H.Blust. 1994. Effects of lampricide treatments, relative to environmental conditions, on abundance and sizes of salmonids in a small stream. North American Journal of Fisheries Management 14:162-169.

A study into the effects of the lampricide TFM (3-triflouromethyl-4-nitrophenol) on a small tributary of Lake Superior, focusing mainly on the stream’s population of Brook Trout (Salvelinus fontinalis). The study looks at not only the mortality of the fish in the stream, but also changes in their relative sizes due to the lampricide. The study showed that the average size of the Brook Trout in the creek tended to be smaller when the chemicals were added earlier in the season. According to the study, the optimal time of year to add TFM is later in the growing season, so that the young fish of the year can grow stronger and larger and mortality is reduced.

Gilderhus, P.A. and B.G.H.Johnson. 1980. Effects of Sea Lamprey (Petromyzon marinus) control in the Great Lakes on aquatic plants, invertebrates, and amphibians. Canadian Journal of Aquatic Sciences 37:1895-1905.

This paper takes the position that chemical treatment of streams to control the introduced Sea Lamprey (Petromyzon marinus) is beneficial, that is, that the impact on aquatic plants, invertebrates, and amphibians is "minor when compared with the benefits." It focuses on the two most commonly used lampricides: 3-triflouromethyl-4-nitrophenol (TFM) and 2’,5-dichloro-4’-nitrosalicylanilidae (Bayer 73). Each of these two chemicals, as well as the combination of the chemicals, is discussed separately and the effects of each on aquatic plants, crustaceans, aquatic insects, and vertebrates (mostly amphibians) are looked at. It appears that TFM is the most deadly to these other aquatic inhabitants, even more so than the combination of the two.
 

Jensen, A.L. 1994. Larkin’s predation model of Lake Trout (Salvelinus namaycush) extinction with harvesting and Sea Lamprey (Petromyzon marinus) predation: a qualitative analysis. Canadian Journal of Fisheries and Aquatic Sciences 51:942-945.

An investigation into the causes of the population crash of Lake Trout (Salvelinus namaycush) in the Great Lakes after the invasion of the exotic Sea Lamprey (Petromyzon marinus). There are two generally agreed upon causes for this population crash: i) rampant predation by Sea Lampreys after they were accidentally introduced into the upper Great Lakes, and ii) extensive overharvesting of the Lake Trout. Experts, however, disagree as to which degree each of these factors played in the problem. Larkin’s mathematical model for predation is used to better understand the relationship between predation and overharvest in the near extinction of the Lake Trout in the upper Great Lakes.
 

Moore, H.H. and L.P.Schleen. 1980. Changes in spawning runs of Sea Lamprey (Petromyzon marinus) in selected streams of Lake Superior after chemical control. Canadian Journal of Fisheries and Aquatic Sciences 37:1851-1860.

The premise of this study is to determine how the Sea Lamprey (Petromyzon marinus) changes the location of its major spawning streams following lampricide treatments. While some treated streams had a decrease of up to 99% of the spawning lampreys, other streams saw little or no change in the populations of this introduced parasitic fish. The study poses that adult lampreys may come in contact with older juveniles at sea and, since these fish have obviously come from suitable streams, followed them to their home streams to breed, thus changing the breeding distribution of these fish away from toxic streams and towards less harmful ones.
 

Schuldt, R.J. and R.Gould. 1980. Changes in distribution of native lampreys in Lake Superior tributaries in response to Sea Lamprey (Petromyzon marinus) control, 1953-77. Canadian Journal of Fisheries and Aquatic Sciences 37:1872-1885.

Three species of lamprey native to the Lake Superior drainage have had marked population declines in recent years since the inception of chemicals to control the spread of the introduced Sea Lamprey (Petromyzon marinus). These three species are: American Brook Lamprey (Lampetra lamottei), Northern Brook Lamprey (Ichthyomyzon fossor), and Silver Lamprey (Ichthyomyzon unicuspis). The Silver Lamprey was the most seriously affected, especially in the area around the St.Mary’s River. Many of the streams in the Lake Superior drainage that were treated have seen populations of all three species either plummet or disappear altogether. The study summarizes the changes in populations of these three species in many of the treated streams.
 

Smith, B.R. and J.J.Tibbles. 1980. Sea Lamprey (Petromyzon marinus) in Lakes Huron, Michigan, and Superior: history of invasion and control, 1936-78. Canadian Journal of Fisheries and Aquatic Sciences 37:1780-1801.

A summary of the history of the invasion of the Sea Lamprey (Petromyzon marinus) into the upper Great Lakes, where it is not native. The paper also describes many of the various methods used to control the spread of this fish into streams where it spawns. The effects of lampreys on native fish stocks are described, since many of these fish are commercially valuable species. Three methods of control are discussed: mechanical barriers, electrical barriers, and chemical treatment of streams. An emphasis is placed on developing new methods of control to lessen dependence on the chemical treatments, which is the most widely used method today and is harmful to native populations of plants and animals that also inhabit these streams.
 

Torblaa, R.L. and R.W.Westman. 1980. Ecological impacts of lampricide treatments on Sea Lamprey (Petromyzon marinus) ammocoetes and metamorphosed individuals. Canadian Journal of Fisheries and Aquatic Sciences 37:1835-1850.

This study not only looks at which streams have seen a decrease in lamprey populations since lampricide treatments began, but also at changes in the sex and age structures of the lampreys that inhabited treated streams. The effects of treatment on growth, abundance, and sex composition in all of the Great Lakes are discussed. The study emphasizes the fact that Sea Lamprey (Petromyzon marinus) populations have declined drastically in many streams that were formerly infested with the fish and chemical control is the reason for this decline.