Lamprey Temporal range:
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A European river lamprey (Lampetra fluviatilis) | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Chordata |
Infraphylum: | Agnatha |
Class: | Hyperoartia |
Order: | Petromyzontiformes Berg, 1940[2] |
Type species | |
Petromyzon marinus | |
Subgroups | |
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Lampreys /ˈlæmpreɪz/ (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes /ˌpɛtroʊmɪˈzɒntɪfɔːrmiːz/, placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin lampetra, which may mean "stone licker" (lambere "to lick" + petra "stone"), though the etymology is uncertain.[3] Lamprey is sometimes seen for the plural form.[4]
There are about 38 known extant species of lampreys and five known extinct species.[5] They are classified in three families: two species-poor families in the Southern Hemisphere and one speciose family in the Northern Hemisphere; phylogenetic studies indicate a mid-Mesozoic divergence for all three, underlying the separation of Laurasia and Gondwanaland. The occurrence of modern lampreys only since the Mesozoic (with significant genus & species radiations only in the Cenozoic) contrasts with the Paleozoic origins of the group and its basal nature.[6]
Parasitic carnivorous lampreys are the most well-known species, and feed by boring into the flesh of other fish to suck their blood;[7] but only 18 species of lampreys engage in this micropredatory lifestyle.[8][9] Of the 18 carnivorous species, nine migrate from saltwater to freshwater to breed (some of them also have freshwater populations), and nine live exclusively in freshwater. All non-carnivorous forms are freshwater species.[10] Adults of the non-carnivorous species do not feed; they live on reserves acquired as ammocoetes (larvae), which they obtain through filter feeding.
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