Fatlips Minnow: Facts & Habitat

About Fatlips Minnow

The fatlips minnow (Phenacobius crassilabrum) is a species of suckermouth minnow that was first described in the upper Tennessee River system. No fewer than 20 specimens were used for description, and the epithet crassilabrum (from the Latin crassus meaning thick or fat and labrum, or lip) was assigned to the species, separating it from Phenacobius catostomus, with which it had previously been identified. The first holotype specimen collected in 1947 was an adult female 8 millimetres (0.31 in) in length from the River.

NativeFresh4 states

Geographic distribution

The distribution of the fatlips minnow is restricted to North America, where it occurs in the upper Tennessee River drainage in western Virginia, western North Carolina, eastern Tennessee and northeastern Georgia. Its habitat is gravel and riffles in small to medium creeks. The fatlips minnow is believed to have arisen from a P. catostomus -like stock population that re-invaded the upper Tennessee River via reciprocal stream piracy. A genetic sister relationship between P. crassilabrum and P. uranops has been consistently resolved. The ranges of P. crassilabrum and P. uranops complement one another in the Tennessee River system, with the former opting for higher elevations. In Virginia, P. crassilabrum occupies the lower free-flowing portion of the South Fork of Holston River and Laurel Creek.

There are documented instances of nonindigenous (out-of-range) occurrences of Phenacobius species; these are believed to be a result of fishermen releasing their unused baitfish into local bodies of water. The current population of P. crassilabrum is presumed to be about 10,000 individuals.

Ecology

P. crassilabrum is known to favor gravel riffles in the warm clear waters of small to medium-sized streams and rivers. Species of the genus Phenacobius remain near the bottom of streams, rooting in the ground for their prey of detritus and aquatic insects such as mayfly and caddisfly larvae.

Life history

Breeding activity has not been observed in P. crassilabrum. Spawning for other Phenacobius species occurs in the spring and summer (April to August). Spawning events take place in the preferred gravelly riffles, allowing the released eggs to seek out nooks and crannies within the substrate. The maximum life span described in the genus is three years.

Management

P. crassilabrum, while existing in small numbers in comparison to other species sharing its ecosystem, is considered to be of the least concern in terms of conservation status (IUCN) and its population is considered stable. An additional factor to consider is the movement of non-native fish into the range of P. crassilabrum, threatening habitat and resource availability.

Article text: Wikipedia contributors, Fatlips minnow (source revision). Licensed under CC BY-SA 4.0. Retrieved 2026-10-11.

Diet and feeding

The FishTraits compilation records these diet categories for this species: invertebrates or larval fish. These are broad categories, not a claim that every individual consumes every example in a category.

Reported feeding positions include bottom feeding. The compilation combines published observations; diets can vary with age, locality, and available food.

Habitat preferences

Reported habitat associations include streams and small rivers.

The source records associations with gravel, cobble, boulders. An association indicates reported use, rather than an exclusive requirement.

Reproduction and parental care

The compilation reports a representative maturity age of 1 years. Its maturity field summarizes mean, median, or modal estimates, usually for females; male estimates can be used when female data are unavailable. It is not a fixed age at which every fish first breeds.

Recorded spawning months are Apr, May for the source’s reporting region (NC). This is a regional calendar, not a range-wide schedule.

The reproductive-guild classification includes guarding eggs or young at a spawning substrate or nest.

Size and recorded longevity

FishTraits reports a maximum total length of 11 centimetres. Some entries use an estimated asymptotic length; this value should not be treated as a certified record catch.

Recorded longevity in the compilation is 3 years. Wild observations were preferred, but captive records were accepted where wild records were unavailable, and unspecified records were assumed wild. The value is not a guaranteed wild lifespan or an aquarium life expectancy.

Range

Where it lives

82.5%of mapped records

Share of 292 GBIF observation records with a state location, across 4 states. The orange dots are USGS stream-survey sites where this species was caught.

A blank area on the dot layer usually means nobody sampled there, not that the fish is absent. Turn on “every survey site” to see where the survey looked.

Share of records by state

The USGS stream survey caught it at 50 of its sites, in 3 states. That survey and the GBIF records are two different counts of two different things, so the site keeps them apart.

Habitat

Water and movement

Water: WoRMS records this species in fresh water.
Migration: Undetermined

Classification

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Superclass: Actinopterygii
Class: Teleostei
Order: Cypriniformes
Family: Leuciscidae
Genus: Phenacobius
Species: Phenacobius crassilabrum
ITIS TSN: 163504
WoRMS AphiaID: 1013680
GBIF key: 2363798

Common questions about Fatlips Minnow

What is the scientific name of Fatlips Minnow?

The scientific name is Phenacobius crassilabrum, in the family Leuciscidae. Classification follows ITIS.

Does Fatlips Minnow live in fresh water or salt water?

WoRMS records this species in fresh water.

Where has Fatlips Minnow been recorded in the United States?

GBIF has observations in 4 states, with the most records in North Carolina, Tennessee, Virginia. The map shows observation records, which do not establish the complete natural range.

Closest relatives