#catostomidae

Oh that's easy...

THE CHUBSUCKERS (Erimyzon spp.), family Catostomidae, order Cypriniformes, found in freshwater in North America

Smallmouth Buffalo Ictiobus bubalus

A sucker fish found in the Mississippi Basin in the United States. One of the longest-lived fishes, it is capable of living more than a century. The smallmouth buffalo is in decline across large portions of its range, and is subject to unregulated exploitation.

Not all buffalo live on the plains; some have made their home right in central North America's rivers! The bigmouth buffalo fish is the largest North American member of the Catostomidae or "sucker" family, reaching up to 1.2 m (4 ft) and 36 kg (80 lbs)! They are also the longest-lived freshwater fish, with many individuals easily reaching 100 years in age.

(Image: A pair of bigmouth buffalo fish (Ictiobus cyprinellus) by Joel Sartore)

The scriptures tell us that everybody's got a water buffalo, but this may not be the one you're thinking of. Instead of a wetlands-loving bovine, this post is about buffalo fish, a genus of 5 large freshwater fish from North America. Buffalo are easily overlooked, but they are pretty interesting fish and I'm here to show you.

(Image: a smallmouth buffalo in profile. It is a large, robust fish that looks brown under this lighting, It has a slightly elongated head with a mouth facing down and a hump behind the head. The scales behind the head are large and prominently outlined. End ID)

Buffalo are members of the genus Ictiobus, which is a member of the family Catostomidae, also known as the suckers. Suckers are a large family of freshwater fish who are, with the exception of 2 species, exclusively found in North America. The buffalo are the largest suckers. Three species, the bigmouth (Ictiobus cyprinellus), smallmouth (Ictiobus bubalus) and black buffalo (Ictiobus niger) are fairly well known, with the bigmouth being the most studied of them. The other two species, the fleshylip buffalo (Ictiobus labiosus) and Usumacinta buffalo (Ictiobus meridionalis) are less well-known. Buffalo are commonly mistaken for carp, but they are not closely related.

(Image: a black buffalo. It looks similar to the smallmouth buffalo, but is darker in color, especially near the top, and its mouth is larger and facing at an angle, rather than directly downwards. End ID)

The bigmouth buffalo is the largest of the species and the largest sucker, capable of growing to over 1.2 m (4 ft) and 36 kg (80 lbs). They are the roundest of the buffalo, with roughly cylindrical bodies. The scales are an olive green and some will develop orange or black spots as they age Bigmouths can be distinguished from other buffalo by their mouths, which open facing forward (terminal). All other buffalo have mouths that open downwards (subterminal). The bigmouth buffalo also differs from the other buffalo in being a filter feeder, while the others are bottom feeders. They have very fine gill rakers that are used to filter plankton out of the water. Bigmouth buffelo are noted for feeding on the larvae of invasive zebra mussels and Asian clams, making them valuable for population control. Young bigmouth buffalo have a feeding strategy similar to their relatives, being mostly bottom feeders that catch and consume small invertebrates like copepods and insect larvae. As they grow, they will switch to a filter feeding lifestyle and will feed throughout the water column. They are known to feed both near the surface and near the bottom. Those who feed near the bottom utilize a unique up and down nodding movement while feeding, which is believed to help them catch plankton that live near but not on the bottom.

(Image: a bigmouth buffalo. It looks like the smallmouth and black buffalo but it lacks the humped back and its mouth faces forward rather than being on the bottom of the head. End ID)

The bigmouth buffalo has the longest known lifespan of any freshwater bony fish, with the oldest individual on record being 127 years old. Furthermore, they do not show the common signs of aging that most animals do, such as lengthened telomeres and a reduction on immune system functioning. In fact, they seem to get healthier as they age and the maximum lifespan is unknown. This seems like a good thing, but it actually leads to problems caused by humans and they relate to reproduction. Bigmouth buffalo can go years between spawns as they need the right conditions, which is warm, spring water that floods highly vegetated habitat in lakes and backwaters. They spawn in groups, with females laying possible millions of eggs (250,000 eggs per kilogram of weight) that are sticky and adhere to vegetation, where the males fertilize them. After hatching, the larvae and juveniles will live in still, shallow water until they grow large enough to move into deeper lakes and rivers as adults.

(Image; a bigmouth buffalo held in two hands to show its size. Its mouth is open and it has orange spots scattered across its body. End ID)

Smallmouth Buffalo are typically lighter in color than bigmouths, with small mouth that face downward and a noticeable hump behind the of the head. The mouth is small, with prominent lips. They typically reach 40 - 60 cm (16 - 24 in) long, but can grow to over 100 cm (40 in) and 30 kg (66 lbs). Smallmouth buffalo prefer streams and rivers with actively flowing water and can tolerate high mineral content and pH. They are bottom-feeding detritovores who use their mouths to take in mud and other sediment, when they then filter for edible particles with their gills. The smallmouth buffalo diet includes decaying organic matter, algae, zooplankton, insect larvae, small crustaceans, small invertebrates, and aquatic plants. Like bigmouth buffalo, they spawn in shallow water among aquatic vegetation and grow slowly. The lifespan of smallmouth buffalo is unknown, but there have been reports of individuals over 90 years old, indicating they also have a very long lifespan.

(Image: a smallmouth buffalo looking toward the camera showing the small size of its head and mouth. End ID)

Black buffalo are visually similar to smallmouth buffalo. The keys to telling them apart is that black buffalo are typically darker in color, have a larger mouth that opens at an angle rather than directly down, and lack the humped back. They typically reach 50 - 76 cm (20 - 30 in) and 4.5 - 13.6 kg (10 - 30 lbs) but have been recorded reaching up to 123 cm (48.5 in) and 36 kg (80 lbs). They occupy a similar ecological and behavioral niche niche to smallmouth buffalo, but will feed in faster-moving and deeper water. Like the other species, they spawn in vegetated water. Black buffalo can hybridize with both bigmouth and smallmouth buffalo. Black buffalo have also been reported living over a century.

(Image: a black buffalo held in two hands. End ID)

I couldn't fine enough information about the fleshylip or Usumacinta buffalo to warrant paragraphs for either of them. Admittedly, I am writing this at about 8 pm the day before posting it so I'm not in the position to be super thorough. They are both native to Mexico.

(Image: an Usumacinta buffalo held by an angler. Ir looks like a smallmouth buffalo but with a larger mouth and reddish scales. End ID)

Bigmouth, smallmouth, and black buffalo are currently classified as least concern by the IUCN, but now research is showing that the situation may be much worse for them. Studies have shows that bigmouth buffalo are not having successful reproduction events, with one study from last year showing that most of the individuals in a lake are decades old and there hasn't been a widely successful reproduction event in 50 years. Young buffalo in that lake surviving to adulthood is a statistical outlier. Unfortunately, buffalo are badly understudied by conservationists so we don't know why they're failing to reproduce and what conservation needs they have. Buffalo also have very little legal protection in the USA, with many states having no limit for non-commercial harvesting. They are used as a food fish and are increasingly popular targets for bowfishing and rod and reel fishing. In addition, the growing awareness of environmental concerns has ironically resulted in people removing and killing bigmouth buffalo after mistaking them for invasive carp. Because we don't know the maximum age of buffalo and don't understand their conservation needs, there could be a major population crash coming and we just don't know about it.

This is the Bigmouth Buffalo (Ictiobus cyprinellus), a fish endemic to the Mississippi and Hudson Bay drainages. And recently, using thin sectioned otoliths and bomb-radiocarbon dating, researchers found this fish can reach 112 years of age, making this the oldest known bony freshwater fish.

 - Otolith of an old Bigmouth Buffalo. Yellow triangles indicate decade counts. Scale bar = 1 mm

Otoliths are a calcium carbonate structure in the inner ear of bony fishes. These organs allows  to perceive linear acceleration, both horizontally and vertically. Counting the annual growth rings on the otoliths is a common technique in estimating the age of fish.

The bigmouth Buffalo is one of the largest freshwater fishes endemic to North America, reaching lengths exceeding 1.25 m and body masses around 40 kg But little is know about its biology, researchers claim this species and simmilar species require urgent attention, as they are under an unregulated fishing pressure.

Larval Quillbacks (via USFWS Midwest Region)

These larval quillbacks were collected by the Green Bay Fish and Wildlife Conservation Office in Lake Michigan. The different sizes are placed next to each other to show how the body form drastically changes as the fish grows.

Smallmouth Buffalo (Ictiobus bubalus), family Catostomidae, found in the Mississippi and Missouri River Basins of North America