The blackspotted topminnow, ''Fundulus olivaceus'', is a species of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

in the family

Fundulidae Fundulidae is the family of topminnows and North American killifishes. Distribution The 46 species are native to North America as far south as Yucatan, and to the islands of Bermuda and Cuba, occurring in both freshwater and marine environments ...

: the topminnows and North American killifishes.Froese, R. and D. Pauly, Eds
''Fundulus olivaceus''.
FishBase. 2011. It is native to the south-central United States, where it is known from the drainages of the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it fl ...

from

Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockf ...

to the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

and as far west as Galveston Bay. This species lives in clear streams with fast currents and sand or gravel substrates. It can often be found near the thick vegetation along the banks of the streams. It is omnivorous, consuming some plant matter along with a main diet of insects and other arthropods.

Description

The blackspotted topminnow has an elongate body up to 9.7 centimeters long. It is brownish yellow to olive green on its upper side and has a wide, dark lateral band and distinct dark spots. The male has longer fins than the female and the fins of the male may take on a yellowish color during breeding. This species is very similar to the blackstripe topminnow (''Fundulus notatus''), which also has a dark lateral band. It can be distinguished from ''F. notatus'' by its darker, more numerous spots. The two may

hybridize Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nu ...

.Hendrickson, D. A. and A. E. Cohen
''Fundulus olivaceus''.
Fishes of Texas Project and Online Database (www.fishesoftexas.org). Published by Texas Natural History Collection, a division of Texas Natural Science Center, University of Texas at Austin. 2012. In ''Fundulus olivaceus,'' the gill slit extends the dorsal to the uppermost pectoral fin ray. The distance from the origin of the dorsal fin to the end of the hypural plate is less than the distance from the origin of the dorsal fin to the preopercle or occasionally about equal to that distance. The mouth is sightly supraterminal.

Diet

The blackspotted topminnow eats various arthropods and algae.

Habitat

This species occurs near the surface in quiet or flowing, relatively clear, sand-gravel bottom headwaters, creeks, and small rivers; often occurring along margins near thick stands of emergent vegetation.

Reproduction and life cycle

Spawning season for the blackspotted topminnow stretches from March to early September, with peak spawning occurring in May.Blanchard, T. A. 1996. Ovarian cycles and microhabitat use in two species of topminnow, ''Fundulus olivaceus'' and ''F. euryzonus'', from the southeastern United States. Environmental Biology of Fishes. 47:155-163. On occasion, large males have been observed keeping an open territory of three square meters, Males seldom tolerate females in the wild, except during morning or evening spawning activities. In the aquarium, however, thus fish loses its wild traits, and becomes less aggressive. When spawning approaches, though, the males start to reveal their wild, aggressive traits. The males will approach each other head-on, and exhibit flaring opercula and gular areas-very similar to cichlid or betta behavior. They will then begin to slap and bite each other's flanks until one backs down. Ripe eggs are an average of 2.14 mm in diameter. The outer egg membrane has filaments that tend to be restricted to one area forming a tuft. The eggs hatch in 10–14 days and live for about 3 years

Distribution

Range of the blackspotted topminnow includes the Gulf Slope, from Galveston Bay drainage, Texas, east to Choctawhatchee River system, Florida, and middle Chattahoochee River drainage, Georgia; Mississippi River basin from the Gulf to southeastern Kansas, central Missouri, southern Illinois, western Kentucky, and eastern Tennessee.

Etymology

The scientific name of the blackspotted topminnow can be broken down in order to understand its meaning. The genus name ''Fundulus'', is from the Latin name ''Fundus'', meaning "bottom". The species name ''olivaceus'' means "olive-colored".Pflieger, W. L. 1975. The fishes of Missouri. Missouri Department of Conservation, Jefferson City. 372 pp.

References

{{Taxonbar, from=Q6422037 O Freshwater fish of the United States Endemic fauna of the United States Fish of the Eastern United States Fauna of the Plains-Midwest (United States) Fauna of the Southeastern United States Least concern biota of the United States Taxa named by David Humphreys Storer Fish described in 1845