Nature

Lampreys: Terrifying Alien Monsters or Fascinating Historic Fishes? – Canadian Museum of Nature Weblog


Lampreys get a foul rap. Their tooth-filled oral disks positively look scary. Elongate squirmy exoparasites are really horrifying. However right here’s the factor: these historical fishes are historical survivors that are a key element of freshwater ecosystems. 

Specialists disagree, however there are anyplace between 42 and 48 species, all however 5 discovered in northern temperate areas. They happen from Alaska to Newfoundland in North America, and Portugal to Siberia in Asia. Though they might seem like eels, they’re very completely different from trendy bony fishes. These cartilaginous fishes lack jaws, scales, and pectoral and pelvic fins. Most are small, round 15 cm, however one species—the Sea Lamprey—reaches 120 cm in marine environments. Totally different species will be recognized by tooth sample.  

A cylindrical creature with circular rows of teeth at one end.
The oral disc of a Sea Lamprey collected on the St. Lawrence River at Saint-Vallier, Québec. This is an grownup specimen of the seagoing type of Petromyzon marinus. Picture: Brian Coad © Canadian Museum of Nature

Throughout their life cycle, lampreys move by means of two phases: larval and grownup. The larval kind—referred to as an ammocoete—burrows in mud and silty areas in rivers and streams. They reside there for anyplace between two and 19 years, filtering feeding microbes, detritus and algae. This sort of feeding technique signifies that they take in chemical substances and different pollution from the water. As a consequence, they have been used to establish precisely what sort of air pollution is discovered in particular rivers. Some species are parasitic as adults, attaching themselves to different fishes to scrape muscle tissue and ingest blood, then develop for a 12 months or extra earlier than spawning and dying. Some species don’t even feed as adults; they solely reside lengthy sufficient to breed as soon as. 

Larval lampreys are essential for nutrient recycling in rivers. Their burrowing aerates the river mattress. Moreover, ammocoetes are eaten by many sorts of fish, together with White Sturgeon in the Pacific rivers. Lampreys as soon as made up an enormous biomass, taking part in a major function within the total ecological integrity of Pacific coastal rivers. Some of the northern colonies of American White Pelicans feeds closely on grownup Arctic Lampreys in Slave River within the Northwest Territories. Seals and sea lions additionally prey on grownup lampreys. Younger salmon feed on them when they’re very small, whereas sturgeon devour residing and lifeless grownup lampreys. Lifeless lamprey our bodies present marine-derived vitamins and natural matter to close by forests by means of birds and mammals scavenging their carcasses.  

An animal that appears greyish-pink and worm-like with a distinct tail and a slight enlargement of the head.
An ammocoete of the American Brook Lamprey (Lethenteron appendix) from the Richelieu River in southern Québec. This specimen is roughly 7 cm lengthy. Picture: Brian Coad © Canadian Museum of Nature

Ammocoetes of Alaskan Brook Lamprey (Lethenteron alaskense), collected by electrofishing from the Martin River within the Northwest Territories. Video: Noel Alfonso © Canadian Museum of Nature

It might shock you to be taught that individuals have and proceed to eat lampreys, notably in Europe. Baked lamprey pie was a typical dish served to the British monarchy. Henry I even died from consuming “a surfeit of lampreys.” Many First Nations peoples within the Pacific Northwest ate Pacific Lampreys, whose oil was drastically valued for dwelling use and commerce. 

Lampreys are an intriguing group of fishes. They’re numerous, are integral parts of many ecosystems and have stunning hyperlinks to people. As an alternative of being feared, they deserve some appreciation. 

A number of large pelicans feeding on an eel–like fish.
American White Pelicans feeding on Arctic Lampreys in Slave River. Picture: © John David McKinnon

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