U.S. Fish & Wildlife Service Maryland darter Etheostoma Sellare

Introduction The Maryland darter is a small freshwater fish only known from a limited area in Harford County, Maryland.

These areas, Swan Creek, Gashey’s Run (a tributary of Swan Creek) and Deer Creek, are part of the larger Susquehanna River drainage basin. Originally discovered in Swan Creek nymphs. Spawning is assumed to species of darters. Electrotrawling is in 1912, the Maryland darter has not occur during late April, based on other the method of towing a net from a boat been seen here since and only small species, but no Maryland darters have with electrodes attached to the net that numbers of individuals have been been observed during reproduction. send small, harmless pulses through found in Gashey’s Run and Deer the water to stir up fish. Electrofishing Creek. A Rare Species efforts in the Susquehanna are Some biologists suspect that the continuing. Due to its scarcity, the Maryland Maryland darter could be hiding darter was federally listed as in the deep, murky waters of the A lack of adequate surveying of endangered in 1967, and critical Susquehanna River. Others worry large rivers in the past due to limited habitat was designated in 1984. The that the decreased darter population technology leaves hope for finding darter is also state listed. The last is evidence that the desirable habitat Maryland darters in this area. The new known sighting of the darter was in for these fish has diminished, possibly studies would likely provide definitive 1988. due to water quality degradation and information on the population status effects of residential development of the Maryland darter and a basis for Characteristics in the watershed. The decreased updating the federal listing status or The Maryland darter is related to the population is also a possible indication future research needs. yellow perch and walleye. It grows of the species’ vulnerability to small to just under three inches and has a population effects such as inbreeding U.S. Fish and Wildlife Service relatively short life span averaging depression. 300 Westgate Center Drive around three years. The rarity of this Hadley, MA 01035 species has made it difficult to study, so Latest Recovery Efforts 413/253 8630 little is known of the specifics of its life After the completion of a five-year history and habitat requirements. review of the Maryland darter in Chesapeake Bay Field Office 2007, biologists concluded that a great 177 Admiral Cochrane Drive Like other darters, this species prefers amount of uncertainty still exists about Annapolis, MD 21401 rock crevices and similar shelters in the darter’s status and that another 410/573 4599 clean, well-oxygenated, swiftly flowing two years of intensive surveying was parts of streams. The Deer Creek necessary. U.S. Fish & Wildlife Service location, historically known for the 1 800/344 WILD highest population numbers of darters, Since then, researchers have http://www.fws.gov is characterized by a steeply sloped continued studies on the darter in the riffle of rock, including rubble and Susquehanna tributaries and in the April 2011 gravel, and swiftly flowing water with Susquehanna River main stem below moderate vegetation. the Conowingo Dam. New techniques for electrotrawling across the bottom of This bottom-dwelling fish eats small large rivers were tried on a small scale insects including small snails, caddis in the Susquehanna in August 2008 and fly larvae, mayfly larvae and stonefly shown to be useful in locating other

Maryland darter illustration by David Neely, provided by Maryland Department of Natural Resources