River Carpsucker, Carpiodes carpio
River Carpsucker, Carpiodes carpio. Fish caught from the Kaskaskia River, Shelbyville, Illinois, July 2015. Length: 38 cm (15 inches). Catch, photograph, and identification courtesy of Ben Cantrell, San Diego, California.
The River Carpsucker, Carpiodes carpio, is a member of the Carp and Minnow or Cyprinidae Family, and is also known as the Cold Water Buffalo, the Quillback, the Silver Carp and the White Carp, is known in Mexico as matalote chato. Globally, there are three species in the genus Carpiodes, with all three found in all freshwater systems of Mexico.
The River Carpsucker has a high arch on the back between the head and the dorsal fin origin (which is larger in older individuals) and has a deep, stout and compressed body. They are silvery with a golden tint or a light green in color with a dull gray or brown area dorsally. Their fins are opaque but turn to dark yellow with maturity. The sexes are dimorphic with males maturing at a younger age than females. The males develop small tubercules on their body during breeding season. Their anal fin has 7 to 9 rays; their caudal fin has 18 rays; their dorsal fin has 23 to 30 rays and has a long base, and the rays are much longer anteriorly, and are sickle shaped; their pectoral fins have 15 to 18 rays; and, their pelvic fins have 8 to 10 rays. Their head has a square snout, a large eye and a subterminal mouth extending past the anterior edge of the eyes, that is equipped with pharyngeal teeth and has a nipple-like projection on the center of the lower lip. They are covered with large scales.
The River Carpsucker is a demersal schooling species that can be found in large groups in turbid waters in quiet, silty or sand bottomed pools of mid-size, and in large streams and rivers, slow moving currents and reservoirs. The juveniles are found in streams and tributaries. They are highly adaptive to various kinds of habitat. They reach a maximum of 64 cm (2 feet 2 inches) in length and 4.6 kg (10 lbs 2 oz) in weight. As of January 1, 2023, the International Game Fish Association world record stood at 3.48 kg (7 lbs 11 oz). They have a highly developed sense of hearing, smell, and taste and are omnivorous bottom feeders, consuming algae, detritus, invertebrates, micro-crustaceans, and planktonic plants found in silty substrates. Their juveniles are preyed upon by many of the larger birds and a large number of larger carnivorous fish. The adults are primarily preyed upon by humans. Reproduction is oviparous and polygynandrous (promiscuous). They are known to migrate upstream for up to 10 km (6.2 miles) in the spring when the water temperature reaches 18oC (65oF), to reproduce and then move back downstream after spawning when the water temperatures reach 27oC (81oF). They spawn in large aggregations with each female broadcasting between 5,000 and 200,000 eggs onto silt or sand substrate in the spring. Females can spawn more than one time a year. Their eggs are simultaneously fertilized by the males and adhere to the bottom substrate. The eggs hatch within 8 to 15 days and the fry are left to fend for themselves. They have lifespans of ten years.
The River Carpsucker can be confused with the Highfin Carpsucker, Carpiodes velifer (dorsal fin rays longer than half the dorsal fin base) and various non-native Asian Carp species.
In Mexico the River Carpsucker is found in the drainage basin of the Rio Grande River in the states of Coahuila, Neuvo Leon and Tamaulipas at elevations below 2,135 m (7,000 ft).
From a conservation perspective the River Carpsucker is currently considered to be of Least Concern with stable widely distributed populations. They have been widely introduced intentionally and accidentally by aquaculture and sportfishing. Their long-term viability is threatened by human development and pollutants in their water systems. Historically they were fished commercially for human food.