Lake lamprey
| Lake lamprey | |
|---|---|
_and_Female_(B)_Lake_Lampreys.jpeg) | |
| (A) Spawning male and (B) Spawning female | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Cephalaspidomorphi |
| Order: | Petromyzontiformes |
| Family: | Petromyzontidae |
| Genus: | Entosphenus |
| Species: | E. macrostomus |
| Binomial name | |
| Entosphenus macrostomus (Beamish, 1982) | |
The Lake lamprey, Entosphenus macrostomus, also known as the Vancouver lamprey or Cowichan lamprey, is a species of freshwater lamprey endemic to two North American lakes: Lake Cowichan and Mesachie Lake in Vancouver Island, Canada. The root of the word lamprey is "stone sucker". The lamprey was originally called the Vancouver Island lamprey, until an error in filing shortened it to the Vancouver lamprey. The alternate common name of "Cowichan lamprey" was coined and promoted by the species' describer, Dr. Dick Beamish, who originally identified the species in the 1980's.[1]
Description
An adult lamprey is dark blue or dark brown with a lighter belly, and the body is 11.8-27.3 centimeters in length. The lampreys disc-like mouth is filled with sharp teeth. The Vancouver lamprey has eyes on the top of its head, two dorsal finds, a caudal fin, and an anal fin.[2] This species of lamprey is over 300 million years old, and as such displays primitive traits such as lacking scales, jaws, and bones (the lamprey has cartilage instead). They spend their entire lives in fresh water, unlike their relative the Pacific lamprey.[1]
Distribution and Habitat
The lake lamprey is found only in the Cowichan and Mesachie Lakes on Vancouver Island, and is non-migratory. The lamprey lives and spawns in shallow gravel areas and typically remains in the lake rather than venturing up streams. They have been found to be capable of surviving in saltwater through experimentation but remain in fresh water in the wild.[3] An estimated 1,000 to 2,000 live in the entirety of the two lakes as adults.[4]
Diet
The adults of several lamprey species are hematophagous predators that latch onto other fish species to feed on their bodily fluids. Young salmonids such as Cutthroat trout and the Coho salmon are common prey. Wounds have been known to penetrate into the body cavity of hosts, though the majority of prey is only scarred and is not fatally wounded. Only 15% of prey is estimated to die from lamprey feedings. Lampreys are one of the leading predators of salmonids, as shown by the high frequency of salmonids with scars (50-80%) found in the lakes.[3]
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Reproduction
Lampreys breed once in their life around 8 years of age. Spawning is from May to August in shallow gravel bars or the mouths of creeks in their respective lake. Over 10,000 eggs are produced in 2 to 3 weeks. The ammocoetes larvae can be found in silt, mud, or sand with relatively still water, and feed on fine organic materials.[3] These larvae undergo a metamorphosis after 5 to 6 years in order to become adult lamprey. The adult lifespan is only 2 more years before they return to gravel lake shores to spawn.
References
- 1 2 "The Vancouver Lamprey (aka the Cowichan Lamprey) | Cowichan Watershed Board". www.cowichanwatershedboard.ca. Retrieved 2016-07-22.
- ↑ "Aquatic Species - Details for Vancouver Lamprey". Fisheries and Oceans Canada. 2010-11-17. Retrieved 22 July 2016.
- 1 2 3 "Entosphenus macrostomus summary page". FishBase. Retrieved 2016-07-22.
- ↑ Docker, Margaret (2013-05-07). "Proposed Recovery Strategy for Vancouver Lamprey". Species at Risk Public Registry. British Columbia Ministry of Environment. Retrieved 22 June 2016.
Sources
- Froese, Rainer and Pauly, Daniel, eds. (2012). "Entosphenus macrostomus" in FishBase. April 2012 version.
- World Conservation Monitoring Centre 1996. Lampetra macrostoma. 2006 IUCN Red List of Threatened Species. Downloaded on 3 August 2007.