Biologists discovered the Maryland Darter in 1912 in a creek in Maryland, and the reclusive fish wasn’t seen again until being found in a different creek in the 1960s. Infrequent sightings of the fish continued until it was last seen in 1988.
The Maryland Darter is the only species of freshwater fish in the United States known with certainty to have gone extinct in the past 30 years. Other species of freshwater fishes in the U.S. may have gone extinct – for example several species of whitefishes in the Great Lakes are either extinct or extremely rare, and others clearly are on the verge of extinction – but the Maryland Darter had such a small range and lived in habitats that are easy to sample so that we can be certain the species is gone. Repeated efforts to find it in the past 30 years have been unsuccessful.
The Maryland Darter was known from only two small creeks in the Chesapeake Bay drainage of Maryland. It was discovered and scientifically named in 1913 and was monitored periodically by the Maryland Department of Natural Resources, and others, since its discovery. The last sighting of the species was in 1985 when a single individual was seen during a 24-hour period that involved efforts to find it during the day and at night.
This species was and remains of special interest because it was morphologically quite distinct from other species of darters. Apparently lacking sexual dimorphism – which all of the species of darters show to some degree – and the evolutionary relationships of the Maryland Darter remain unclear. The only information we have on the Maryland Darter, in addition to the limited observations made during fieldwork, are from examinations of specimens in collections. We have two specimens in the fish collection at the Florida Museum of Natural History.
From these and other specimens we know that the species reached only about 3 inches in length and lived to a maximum of about two and a half years. It fed on snails and aquatic insects and probably spawned in the spring of the year. Based on the genital papilla of the female, which is unusual in this species, eggs probably were attached to rocks, where they may have been guarded by a male, a behavior that is known in only a few other species of darters.
The Maryland Darter was an interesting member of our North American freshwater ecosystems. If we had known from the time of its discovery that it was so extremely rare and so limited in its distribution, we might have been able to establish an effective program to protect it. Unfortunately, it was gone before we realized how imperiled it was.
Florida Museum of Natural History
Maryland Darter (Etheostoma sellare)
From Harford Co., Maryland, Oct. 1985