Photo courtesy of Konrad Schmidt
Quillback sucker - Common name
Carpiodes cyprinus - Scientific name
Family - Catistomidae (suckers)
Status : S3, G5
IDENTIFICATION: The quillback sucker has a deep body that is about one third deep as it is long. It can get as long as two feet (600 mm). The body is silver-colored and has large scales. The dorsal fin extends down its back almost to the tail fin. The first few dorsal rays are much longer than the last and give a shark-like shape to the front of the dorsal fin. The head is small and conical in shape, with a long snout that is about the same length as the distance from the back of the eye to the upper end of the gill opening. It has a sucker mouth with no nipple on the lower lip.
SIMILAR SPECIES FOUND IN SOUTH DAKOTA: The quillback sucker looks very much like the river carpsucker and the highfin carpsucker , which are closely related and in the same genus called Carpiodes. The river carpsucker is very common in eastern South Dakota compared to the quillback sucker, whereas the highfin carpsucker is less common than the quillback sucker. One way to tell these species apart is by the length of the first ray of the dorsal fin . The first dorsal ray of the river carpsucker and quillback sucker does not reach to the rear of the dorsal fin, but the first dorsal ray of the highfin carpsucker does reach the rear of the dorsal fin and beyond. The quillback sucker has a longer first dorsal ray than the river carpsucker, but unless you have the two species together it is difficult to notice this difference. To tell the two species apart one needs to look at the mouth. The river carpsucker will have a small nipple in the center of its lower lip, whereas the quillback sucker does not.
HABITS AND HABITAT: The quillback sucker inhabits the pools, backwaters and main channels of large creeks and rivers, and is also found in lakes. The quillback sucker uses its sucker-mouth to "vacuum" the bottom substrate taking in living organisms and detritus (dead organic matter).
DISTRIBUTION: Distribution Map The quillback sucker is found in the Hudson Bay, Great Lakes - St. Lawrence, and the Mississippi River drainages. The quillback sucker is found in large rivers in eastern South Dakota which include the James, Vermillion and Big Sioux Rivers. They have also been found near the mouths of some of the larger tributaries to these rivers. The quillback sucker is found only in the lower reaches of the Vermillion and Big Sioux Rivers, whereas it has been found throughout the James River in South Dakota. River size limits the distribution of this fish in the Vermillion and Big Sioux Rivers. The barrier formed by the falls at Sioux Falls further limits its distribution in the Big Sioux River. The quillback sucker has been documented in Spink, Beadle, and Hutchinson Counties in the James River Basin; Clay County in the Vermillion River Basin; and in Minnehaha, Lincoln and Union Counties in the Big Sioux River Basin. The quillback sucker has also been recorded in Whetstone Creek near where it enters Big Stone Lake in Grant County.
CAUSES OF CONCERN AND CONSERVATION MEASURES: The quillback sucker is not commonly found in South Dakota and is quite rare. Reasons for its rarity may be that it is near the northwestern limit of its range in the Mississippi River Drainage.