The smallmouth buffalo exhibits a range of colors, from shades of gray to brown and coppery green dorsally, transitioning to pale yellow to white ventrally. Its fins are similarly colored, with darker shades towards the tips. This stocky fish features a distinctive hump rising from the operculum. The pectoral and anal fins protrude ventrally, while the caudal fin displays even lobes. The dorsal fin extends from the top of the hump to a blunt point, then shortens and runs the length of the body to the base of the tail. On average, adult smallmouth buffalo measure around 40–60 cm (16–24 in) in length, although exceptional specimens can reach up to 30.1 kg (66.4 pounds) and 101.5 cm (40.0 in).
Smallmouth buffalo are known for their adaptability and thrive in clear, moderate to fast-moving streams. While their primary habitat consists of tributaries and surrounding waters of the Mississippi River, they have been introduced to other water systems as well. The species prefers areas with dense aquatic vegetation and a silty bottom. Remarkably, smallmouth buffalo exhibits a high tolerance for hard water and can survive in pH ranges of 6.5–8.5.
As detritivores, smallmouth buffalo rely on their ventral sucker mouth to feed on vegetation and organic matter found at the bottom of their habitat. They are also invertivores, consuming a variety of prey such as zooplankton, insect larvae, mollusk larvae, and small crustaceans. Furthermore, they exhibit a unique feeding behavior, often scraping algae off rocks.
Spawning of the smallmouth buffalo typically occurs during spring and summer, with specific times varying depending on the population's location. Migration among smallmouth buffalo populations is negligible. During spawning, females lay tens of thousands to hundreds of thousands of eggs, which adhere to vegetation and gravel in shallower sections of streams to prevent them from flowing away. Unlike some other fish species, smallmouth buffalo do not provide parental care, and the eggs hatch within one to two weeks. The young fish seek refuge in aquatic vegetation to avoid predators. While their exact lifespan is not extensively studied, recent research indicates that smallmouth buffalo can live beyond 60 years, with some individuals reaching ages of 39 and even 62 years.
Contrary to the historical perception of smallmouth buffalo as a rough fish, it holds great significance within North American ecosystems. The species is not only the most commonly sold freshwater fish in the United States but is also highly sought after by traditional anglers. In recent years, smallmouth buffalo have gained popularity as a sportfish, particularly due to the rise of modernized night bowfishing, which targets this species. However, the ecological impact of bowfishing and the need for better management strategies remain urgent concerns, as there are currently minimal restrictions on harvest.
Smallmouthbuffalo also holds value as a food source, with its meat being used in human and animal consumption. The fish meal derived from smallmouth buffalo is commonly included in animal feed. Furthermore, these fish are relatively easy to raise in commercial farm ponds, making them a viable option for aquaculture.
In terms of angling records, smallmouth buffalo have garnered attention for their impressive sizes. The International Game Fish Association (IGFA) all-tackle world record for the species stands at 82 lb 3 oz (37.3 kg), caught in Athens Lake, Texas, on May 6, 1993, by angler Randy Collins. Additionally, the current IGFA all-tackle length record is held by a 63 cm (2.07 ft) specimen caught on May 16, 2022, in Livingston Lake, Texas, by James Schmid.