BIO 210


Silver Lamprey Ichthyomyzon unicuspis Hubbs and Trauntman, 1937
Kingdom Animalia
The Silver Lamprey is places in the kingdom Animalia for two reason.  Silver Lampreys are multicellular, meaning they have more than one cell. (Animal Diversity Web)  Silver Lampreys are also heterotrophic, meaning that they cannot make their own food and rely on other organisms for nutrients. (Animal Diversity Web)  Silver Lampreys also show the trait of sexual reproduction meaning that an egg from the female and sperm from the male fertilize in order to make a viable offspring.  This trait is shown in most, but not all organisms in the Kingdom Animalia. (Animal Diversity Web)
Phylum Chordata
The Silver Lamprey resides in the Phylum Chordata because it has a notochord. (Hickman 2012)  All organisms residing in the Phylum Chordata have a notochord during some part of their life cycle.  A notochord is a rodlike, semi stiff cord that usually runs the full length of the organism.  The notochord is a hydrostatic organ and its primary function is to stiffen the body.  It is also used for support in movement.(Hickman 2012, Animal Diversity Web)
Subphylum Vertebrata
Silver Lamprey fall in to the Subphylum of Vertebrata because they have a backbone. (Hickman 2012)  Organisms with in the Subphylum Vertebrata have a vertebral column that usually runs along the dorsal surface of the organism.(Animal Diversity Web)
Superclass Agnatha
Silver Lampreys are in the Superclass Agnatha because they lack a jaw. The Superclass Agnatha consists of organisms that do not have a jaw structure(Hickman 2012).
Class Petromyzontida
Silver Lampreys are in the Class Petromyzontida because they have no jaws bones or paired fins.  They also have a buccal funnel, seven pairs of external gill openings and keratinized teeth around their mouth (Hickman 2012).


Order Petromyzontiformes
Silver Lamprey are placed under the order of Petromyzontiformes because they have no bone, lateral eyes and seven pair of external gill openings.  Also organisms within the order Petromyzontiformes hypocercal tails as ammocoetes and isocercal tails as adults(Order Summary of Petromyzontidae).


Family Petromyzontidae
The family Petromyzontidea describes all northern lamprey species.  Silver Lamprey fit in the family of Petromyzontidea because all members of Petromyzontidea are jawless, contain skeletons made of cartilage and a notocord.  They are eel like in shape and lack scales or paired fins.  The family of Petromyzontidae also have the highest number of chromosomes( 164-174) of any other vertebrate(Family Petromyzontidae-Northern Lamprey).


Genus Ichthyomyzon
Silver Lamprey are included in the Genus Ichthyomyzon because they are restricted to bodies of fresh water in eastern North America.  The species of the Genus Ichthyomyzon are limited bodies of fresh water connected to the  Gulf of Mexico, St. Lawrence River and Hudson Bay( Hardisty, M.W.)  


Species Ichthyomyzon unicupis
The Ichthyomyzon unicupis can be identified from other lampreys in the genus Ichthyomyzon by the pattern and characteristics of it's teeth.  Ichthyomyzon unicupis sucking mouth part is contains two supraoral cusps, five to eleven infraoral cusps, four unicuspids in the lateral circumoral rows, two to four anterior teeth, and five to eight lateral teeth rows (COSEWIC).

Ichthyomyzon is a Greek word meaning “fish to suck” and was meant to refer to the way the lamprey sucks nutrients from its host.  The word unicupis is Latin and means one point meant to describe a single cusp on each tooth(Ichthyomyzon unicupis).


For more information visit Encyclopedia of Life and Pacific Northwest Network

Back to Home