The black buffalo (Ictiobus niger) is a North American species of freshwater fish in the Catostomidae or sucker family. With a lifespan greater than 100 years it is among the longest-lived of freshwater fish species. Found in the Mississippi Basin and southern Great Lakes. It was first discovered in Canada in the western end of Lake Erie and has been reported from Boston Creek. The Tennessee distribution ranges from rivers and streams in the Cumberland Mountains, a few rivers in middle Tennessee, and in west Tennessee along the Mississippi River. The ecology of the species is quite similar to that of I. bubalus. I. niger has a ventrally positioned mouth, making the species’ diet benthic-oriented. It has a distinct shape that mocks I. bubalus and I. cyprinellus, considering it a hybrid between the two species.
I. niger is found in large and small rivers in eastern North America from the Mississippi Basin to Canada. In Canada, the species was first described in Lake Erie. In the United States, the species is found in both small and large rivers in the basins of the Mississippi, Missouri, and Ohio as well as in southern Lake Michigan and Lake Erie. Among others, it is native to Iowa, South Dakota and Minnesota; more southern states include eastern Texas and Oklahoma.
The ecology of I. niger is most closely related to I. cyprinellus. Due to the ventrally positioned mouth, the diet is benthic-oriented, with the Asiatic clam being the principal food. Detritus and sand are also ingested and contribute about 40% of the dietary volume. It is most commonly found in quiet, shallow waters. The U.S. angling record is 55.5 lb (25.2 kg) and was caught in Tennessee in 1984. The typical length is about 20–30 in (51–76 cm) with a maximum length of 48.5 in (123 cm). The typical weight is estimated to be about 10–30 lb (4.5–13.6 kg). A specimen caught in Shelby County, Tennessee, on April 1, 1980, was accepted as valid and weighed 80 lb (36 kg). I. niger relies on benthic organisms more heavily than I. bubalus. I. niger feeds mostly from the bottom.
Members of Ictiobus are large, robust-bodied suckers adapted to large rivers. Currently recognized species are readily diagnosed by morphological characters, and the group is known from fossils dating back to the Miocene. I. niger is a spring spawner. They spawn in flooded areas and backwaters of sloughs and small to large rivers. Fertilized eggs are demersal and adhesive. They hatch in 24–36 hours at 19–24 °C (66–75 °F). I. niger grows fairly rapidly, averaging 13.4 cm (5.3 in) after the first year. It is unknown when black buffalo reach sexual maturity. The spawning period could take days. Spawning fish remain in a state of excitement, and are unconcerned about unusual movements or disturbances. I. niger has been reported violently jumping and repressed eagerness while spawning. The fish do not seem to recover normal reaction to alarm until the spawning draws to an end. The black buffalo can live for more than a century, and thus like other buffalofish species, the black buffalo is extremely long-lived.
