- Federal Status: Not Listed
- FL Status: State-designated Threatened
- FNAI Ranks: G5/S1 (Globally: Apparently Secure/State: Critically Imperiled)
- IUCN Status: Not ranked
The Southern tessellated darter is a small brown fish that can reach lengths of four inches (10.2 centimeters). Both sexes have 9-11 dark “X” or “Y” shaped marks on their side. Breeding males have a larger second dorsal fin than females (Florida Natural Areas Inventory 2001).
The diet of Southern tessellated darters primarily consists of small fish, crustaceans, and insects (Gilbert 1992).
Tessellated darters are thought to begin breeding from January to February, with the females capable of holding 340 eggs (Gilbert 1992). Females lay eggs on rocks or hard substrates with smooth undersides, for which the male will guard heavily (Constantz 1979). Males repel other males and females with erect fins, while allowing females with flattened fins to occupy the area (Constantz 1979). However, the male can be beaten by larger males, which then the larger male will fertilize the eggs (Constantz 1979). Southern tessellated darters reach sexual maturity at 40 millimeters standard length (Gilbert 1992).
The Southern tessellated darter can be found in coastal streams from the Cape Fear River drainage in North Carolina to the St. Johns River in Florida (Cole 1967, Rohde et al. 2009, Florida Natural Areas Inventory 2001). In Florida, the population is found in portions of the North Central part of the state.
The small geographic range and specific habitat occupied by this species in Florida suggests that it may be vulnerable to human sources of pollution and habitat alteration. Specifically, non-point source input (ex. pollution from runoff) of fine sediment into the Ocklawaha watershed in north-central Florida could adversely affect tessellated darters by smothering available spawning habitat or suffocating existing nests. Hybridization (combining varieties of species from one genus) could be a threat if other darter species are introduced. Other threats include the construction of impoundments (ex. water reservoirs) along coastal stream habitats as this can cause water quality alterations and habitat fragmentation.
Cole, C.F. 1967. A study of the eastern Johnny darter, Etheostoma olmstedi Storer (Teleostei,Percidae). Chesapeake Science 8:28-51.
Constantz, G. D. (1979). Social Dynamics and Parental Care in the Tessellated Darter (Pisces:Percidae). Proceedings of the Academy of Natural Sciences of Philadelphia, Academy of Natural Science. Vol. 131, pp. 131-138.
Florida Natural Areas Inventory. 2001. Field guide to the rare animals of Florida. https://www.fnai.org/FieldGuide/pdf/Etheostoma_olmstedi.pdf
Gilbert, C.R. 1992. Southern tessellated darter, Etheostoma olmstedi maculaticeps. Pp. 88-92. In C.R. Gilbert, ed., Rare and Endangered Biota of Florida. Vol. II. Fishes. University Press of Florida, Gainesville.
Rohde, F.C., R.G. Arndt, J.W. Foltz, and J.M. Quatro. 2009. Freshwater Fishes of South Carolina. University of South Carolina Press. Columbia South Carolina. 430pp.