catalog Catostomidae · omnivore

smallmouth buffalo

Ictiobus bubalus

Freshwater

A bottom-feeding fish of the sucker family (Catostomidae), with a deep body and a small downturned mouth, living in rivers and reservoirs of northeastern Mexico. It eats invertebrates and algae and takes natural bait on the bottom.

Also called: peixe-búfalo-de-boca-pequena, peixe-búfalo, smallmouth buffalo

forecast for smallmouth buffalo where found

Scientific illustration of Smallmouth buffalo

common size: 40–65 cm
maximum: 112 cm
common weight: 0.8–3.5 kg
record/max.: 37.3 kg
depth: 1–6 m
ideal water: 18–28 °C

overview

who is the smallmouth buffalo

The smallmouth buffalo (matalote boquín) is a freshwater fish of the family Catostomidae, the family of North American suckers, and one of the buffalo fish of the genus Ictiobus. It is native to the Mississippi basin and to rivers flowing into the Gulf of Mexico, and reaches northeastern Mexico through the Río Bravo basin. It lives in backwaters, canals, and reservoirs of small to large rivers, preferably in clear water with some flow, over mud bottoms with vegetation. It feeds on the bottom: mollusks, insect larvae, small crustaceans, and algae, which it grinds with its pharyngeal teeth. FishBase gives up to 112 cm and 37.3 kg and a maximum age of 15 years, but the common fish measures 40 to 65 cm. The same source classifies it as a commercial and sport species, sold fresh and eaten fried, grilled, or baked.

fun facts

The teeth are in the throat (pharyngeal) and grind mollusks and algae; that is how it feeds on the bottom.
The maximum age recorded in FishBase is 15 years.
Males develop small tubercles on the head during the breeding season, and the eggs are released into the water with no parental care.

how to recognize it

identification

Deep, laterally compressed body, dark gray on the back, bronze to golden flanks, and yellowish white belly. The mouth is small, pointing downward (subterminal), with no barbels, and the dorsal fin is long, with 22 to 30 rays. It is told apart from the bigmouth buffalo (Ictiobus cyprinellus) by that species' terminal mouth, and from the black buffalo (I. niger) by its deeper body: in small fish the difference is hard to see. The introduced common carp (Cyprinus carpio) looks similar, but has barbels and a serrated spine on the dorsal and anal fins.

how smallmouth buffalo fishing looks

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Each card shows the day's index (0 to 100) and, below it, a strip with the index for each hour, from 0h to 23h. from poor to excellent.

distribution

where found

open on the large map

Not found in Brazil. Native to North America: the Mississippi and Great Lakes basins, Gulf of Mexico drainages from Alabama to the Rio Grande in the USA, and northeastern Mexico, in the Río Bravo basin. FishBase does not detail the Mexican rivers.

Habitat: Backwaters, canals, and reservoirs of small to large rivers, in clear to slightly murky water, with vegetation and a mud bottom. Tolerates hard water.

calendar and clock

when to fish

best season

time of yearbest: Apr–Jun

JanFebSeaAprMayJunJulAugSepOctNovDec

Bites best in spring and early summer. Spawning runs from March to September, in water of about 15 to 28 °C, peaking in July in Texas; in cold winters the fish is sluggish. FishBase classifies it as potamodromous, meaning it migrates within freshwater.

best time of day

Any time. The sources consulted do not indicate a preferred time. When in doubt, fish early in the morning and late in the afternoon, when there is less activity on the bank.

weather, water and behavior

what affects the smallmouth buffalo
sensitivity The little bars show how much each factor affects this species. Five full: it feels it a lot.

cold and cold fronts

Water below about 10 °C makes the fish sluggish; a string of cold fronts reduces the bites.

atmospheric pressure

No known effect; stable weather is the most comfortable for bottom fishing.

moon

No known effect.

rain

A moderate rise and slightly murky water can move fish into shallow areas; thunderstorm with lightning: get out of the water.

water level

A river and reservoir at a stable level concentrate fish in backwaters and mud bottoms.

noise

Low to moderate sensitivity; avoid stomping on the bank.

wind

Strong wind makes it hard to control the line on the bottom.

depth

On the bottom, from 1 to 6 m, in backwaters and canals with mud and vegetation.

technique, gear and bait

how to fish

Natural bait on the bottom

rod: 7' to 8', medium action, 10 to 25 lb
spinning / baitcasting reel: spinning reel 3000 to 5000 with good line capacity
line: monofilament 0.28 to 0.35 mm (12 to 20 lb)
leader: monofilament or fluorocarbon 12 to 20 lb, 40 to 60 cm
hook: size 8 to 2, fine and sharp: the mouth is small

lures

rarely used with lures

natural baits

dough ball
milho
minhoca

accessories

sliding sinker
rod holder
landing net

tip from an angler

Use a sliding sinker and slack line: the bite is light. Set the hook firmly when the rod tip drops.

what the law says

rules for the smallmouth buffalo

Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
Conservation: Assessed on Nov 8, 2018 as Least Concern. Species not found in Brazil.

Mexico: up to 5 freshwater fish per day, one rod, and no live fish as bait

5 fish per angler per day; one rod in use; no live fish as bait

In Mexico's federal inland waters, recreational fishing for freshwater species is limited to 5 fish per angler per day (this applies to the matalote as to any freshwater fish). Each reservoir's committee may lower the bag limit and set sizes. Only one rod per angler may be in use, and using live fish as bait is prohibited. Fish kept may not be sold, and any fish over the limit must be returned alive to the water. No permit is required to fish from the bank; a permit is required from a boat.

Source: Amendment to NOM-017-PESC-1994, DOF Nov 25, 2013, items 4.3, 4.6 b, 4.7 c, 4.9.2, 4.9.5 and 4.11 (Sagarpa/Conapesca)

catch and release
catch and release Releasing the fish alive, quickly and with a wet hand. During a closed season it isn't always allowed: what the regulation says applies.

The mouth is small and delicate: remove the hook with pliers, support the fish by its belly, and return it to the water without delay.

in the kitchen

Edible: FishBase reports that it is sold fresh and prepared fried, grilled, or baked. A bony fish, like other suckers.

calculator

how much it weighs without taking it out of the water

total length (cm)

Length-weight relationship W = a·L^b (a = 0.01122, b = 3.01; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.

estimated weight

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sources and references

The season factors (months), the time of day, and the sensitivities (cold, pressure, moon, wind, rain, tide, strong light, murky water, and noise) are editorial estimates by the app, based on the literature cited below and on field experience of anglers and guides. They are not official data or measurements made for this species and may vary by region and year. Closed seasons and legal rules appear in the rules section, with the standard and link. Depth, gear, and baits are editorial recommendations based on the species' habit of feeding on the bottom; there is no specific source on recreational fishing for the species in Mexico.

scientific FishBase: Ictiobus bubalus (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
scientific FishBase: nomes populares de Ictiobus bubalusNames by country and language.
scientific IUCN Red List: Ictiobus bubalus (avaliação global: Pouco Preocupante, LC, 08/11/2018)Global assessment. Link given on the FishBase entry (Red List, version 2025-2).
scientific Fishes of Texas: Ictiobus bubalus (smallmouth buffalo)Identification (subterminal mouth, dorsal fin, comparison with I. cyprinellus and I. niger), habitat, diet, spawning (March to September, 15.5 to 27.5 °C), longevity, and native range. The page covers Texas and does not detail the presence in the Río Bravo. Page checked on Oct 13, 2026.
official DOF: Modificação da NOM-017-PESC-1994, que regula a pesca esportivo-recreativa em águas de jurisdição federal do México (publicada em 25/11/2013)Items 4.3, 4.4, 4.6 b, 4.7 c, 4.9.2, 4.9.5, and 4.11: permit, one rod per angler in inland waters, ban on live fish as bait, limit of 5 freshwater fish per day, release of the fish over the limit, and ban on sale. Text checked on Oct 13, 2026.
official DOF: NOM-060-SAG/PESC-2014, pesca responsável em corpos de água continentais de jurisdição federal do México (publicada em 27/05/2014)The standard mentions the matalote (Ictiobus meridionalis) in commercial fishing nets, but does not name Ictiobus bubalus or set a minimum size for it. For that reason, the profile includes only the general rule for recreational fishing. Text checked on Oct 13, 2026.

don't confuse

similar species

Catostomidae

Black buffalo

Ictiobus niger

Large freshwater fish of North America, present in Mexico and introduced to Cuba, up to 123 cm. It appears in commercial and sport fishing and is raised in aquaculture.

Freshwater

Catostomidae

Bigmouth buffalo

Ictiobus cyprinellus

Large freshwater fish of North America, up to 123 cm, introduced to Cuba. It eats plankton, is raised in aquaculture and appears in commercial and sport fishing.

Freshwater