Classification
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