Domain: Eukaryota

Nearly all life forms on Earth such as plants, animals, and anything else you can see are eukaryotes.  But the majority of Eukaryotes are microscopic, species too small to see with the human eye.  Eukaryotes have membrane bound organelles as well as a membrane bound nucleus.  They are also very complex because of their internal structures. (Encyclopedia of Life)

Kingdom: Animalia

The kingdom of Animalia, also known as Metazoa is characterized by predation, which consists of animals feeding on other animals.  It can also consist of herbivores, eating plants, or detritivores which is feeding on very small decomposing plants and other organic material.
(Encyclopedia of Life)

Phylum:  Chordata

The phylum Chordata covers species of fish, mammals, and all vertebrates alike.  Most species that belong to the phylum of Chordata are very active and are characterized by bilateral symmetry and contain nervous chords in their bodies. (Encyclopedia of Life)

Class:  Actinopterygii

Fish in the Actinopterygii class are characterized as having "rayed fins".  They make up almost half of the phylum Chordata and are the most successful type of fish.  This also makes this class one of the most diverse. (Encyclopedia of Life)

Order:  Perciformes

Although fish in the order Perciformes may include fish from the ocean,  they also include many species that are found in inland lakes, rivers, and streams.  This is why the Etheostoma nigrum is classified into this order.  Fish in the order Perciformes are also characterized by having a habitat close to the shore in shallow waters, especially coral reefs.  (Encyclopedia of Life)

Family:  Percida

 Fish found in the family Percida are characterized by the amount of armor that is found around the head for example having teeth or spines on their checks or around the gills. This family contains 200 different species within 10 different genera. Etheostoma nigrum is part of this family because the majority of the fish are laterally compressed. (Encyclopedia of Life)

Genus:  Etheostoma

Fish in this genus are referred to as to darters. They are small fish with different patterned bodies depending on which species in the genus is being described.  (Encyclopedia of Life)

Etheostoma nigrum

Etheostoma nigrum i
s characterized as being the most thermal resistant species in the Etheostoma family. Also they are marked with a distinct w pattern on this sides of their body. (Encyclopedia of Life)

We highly recommend visiting this website, Encyclopedia of Life, for more information not only of the Etheostoma nigrum, but of many other species of life.