Scientific Name
Etheostoma nigrum

Common Name
Johnny darter

Biology
Occur in sandy and muddy, sometimes rocky, pools of headwaters, creeks, and small to medium rivers; and in sandy shores of lakes (Ref. 5723, 10294); also found in streams (Ref. 10294). Adults feed on midge larvae, mayfly nymphs, caddis larvae, and microcrustaceans; young on entomostracans and tiny midge larvae (Ref. 10294). Eggs are found clustered on underside of stone and guarded by males (Ref. 7043).

Classification

Classified By

Rafinesque, 1820

Class

Ray-finned fishes (Actinopterygii)

Order

Perch-like fish (Perciformes)

Family

Perches (Percidae)

Distribution

Region

North America

Distribution

North America: St. Lawrence-Great Lakes, Hudson Bay, and Mississippi River basins from Hudson Bay to southern Mississippi in the USA, and from Quebec in Canada and from Virginia in the USA to Saskatchewan in Canada and Colorado in the USA; and on Atlantic and Gulf Slope drainages in the USA.

Range

59°N - 32°N

Environment

Climate

Temperate

Water Temperature From

4 °C

Water Temperature To

18 °C

Depth From - meters

Unknown m

Depth To - meters

Unknown m

Zone

benthopelagic

Environment

Freshwater; ; pH range: 7.0 - ? ; dH range: ? - 15 benthopelagic

Trophic Level

3.19 s.e. 0.40 Based on food items.

Occurs in Marine / Salt water

False

Occurs in Brackish water

False

Occurs in Fresh Water

True

Occurs on Reefs

False

Is kept in Aquariums

False

Physical Size and Genetics

Maximum Length

7.2 cm

Common Length

3.9 cm

Phylogenetic Diversity Index

PD50 = 0.5000 many relatives (e.g. carps) 0.5 - 2.0 few relatives (e.g. lungfishes)

Human Uses and Population

Human Uses

Unknown

Vulnerability

Low vulnerability (14 of 100)

Resilience

Medium, minimum population doubling time 1.4 - 4.4 years (K=0.95; tmax=4; Fec=47-691)

Threat To Humans

Harmless

IUCN Red List Status

Not Evaluated