Crystal Darter: Crystallaria asprella
Genus/Species: Crystallaria asprella
Common Name: Crystal darter
Federal Status: Not Listed
FL Status: State-designated Threatened
FNAI Ranks: G3/S1 (Globally: Rare/State: Critically Imperiled)
IUCN Status: VU (Vulnerable)
The crystal darter is one of the larger members of the Family Percidae (Gilbert 1992). This species can reach a body length of six inches (15.2 centimeters). Crystal darters are a light brown fish that have a side-to-side compressed head, large eyes, and four dark saddle marks (the first saddle originating in front of the pectoral fin) on their upper part (Florida Natural Areas Inventory 2001).
Crystal darters are invertivores – they feed on a variety of invertebrates.
Spawning presumably begins in meandering side channels of main waterwaya when water temperatures reach 53.6-59°F (12-15°C). During copulation (mating), females will bury themselves slightly in the substrate (habitat floor). Females can copulate with more than one male at a time. The spawning season usually lasts one week. Fertilized eggs are strongly adhesive and attach to sand and gravel when released by the female. The average egg mass for crystal darters is 106-576 eggs (Boschung and Mayden 2004). Sexual maturity is reached at the age of one year (George et al. 1996).
Habitat and Distribution
Crystal darters inhabit rivers with modest current, sandy riffles, and a sand/gravel bottom of medium to large size streams (Florida Natural Areas Inventory 2001). They can be found within the Mississippi River basin from Wisconsin and Minnesota east to Ohio, west to Oklahoma, and south to Louisiana and Florida (Boschung and Mayden 2004, Page 1983). In Florida, crystal darters occur in the Escambia River.
The crystal darter in Florida represents a separated population as it is isolated from any potential source population capable of contributing to persistence of the species, which could cause a decline in the population. Crystal darters are threatened with habitat irregularities, as their primary habitat occurs sporadically (Wood and Raley 2001). Other threats include the destruction and degradation of their habitat from channeling, dredging, impounding waterways, and the siltation of these waterways (Grandmaison et al. 2003).
Conservation and Management
The crystal darter is protected as a State-designated Threatened species by Florida’s Endangered and Threatened Species Rule.
Biological Status Review
Supplemental Information for the BSR
Other Informative Links
International Union for Conservation of Nature
Florida Natural Areas Inventory
U.S. Fish and Wildlife Service Status Assessment Report
Printable version of this page
Boschung H.T. and R. L. Mayden. 2004. Fishes of Alabama. The Smithsonian Institution.Washington, D.C. 1-736.
Florida Natural Areas Inventory. 2001. Field guide to the rare animals of Florida. http://www.fnai.org/FieldGuide/pdf/Crystallaria_asprella.PDF
George, S.G., W.T. Slack, and N.H. Douglas. 1996. Demography, habitat, reproduction, and sexual dimorphism of the Crystal Darter, Crystallaria asprella (Jordan), from south central Arkansas. Copeia 1996:68-78.
Gilbert, C.R.. 1992. Crystal darter Crystallaria asprella. Pp. 79-83. In C.R. Gilbert, ed., Rare and Endangered Biota of Florida. Vol. II. Fishes. University Presses of Florida, Gainesville.
Grandmaison, D., J. Mayasich, and D. Etnier. 2003. Crystal darter status assessment report. NRRI Technical Report No. NRRI/TR-2003/19. U. S. Fish and Wildlife Service, Fort Snelling, Minnesota. 53 pp
Page, L.M., 1983. Handbook of Darters. T.F.H. Publishers, Neptune City, New Jersey
Wood, R.M. and M.E. Raley. 2000. Cytochrome b sequence variation in the crystal darter Crystallaria asprella (Actinopterygii: Percidae). Copeia 2000: 20-26.
Image Credit FWC