Other freshwater · Freshwater

Shorthead redhorse

Moxostoma macrolepidotum

Native adaptable redhorse sucker of medium to large rivers across central and eastern North America, favoring silt-free sand, gravel, and rubble.

Also called northern redhorse, redhorse, redfin sucker, shorthead.

  • Flowing water
  • Stillwater
  • Ordinary target
  • 4 of 4 overlays reviewed
  • Reviewed 2026-08-27
22 things this record does not know

Take this somewhere

This page is the record. The reading is what happens when you add water, a season and a temperature to it — that is where the families below get ranked against each other instead of just listed.

Those three links carry the fish and nothing else. No conditions were declared on this page, so none travel, and the link says so rather than sending an empty reading.

The half nobody publishes

What this record does not know

Everything else on this page comes from a named agency or peer-reviewed source. This is the other side of that: the questions a reviewer went looking for an answer to and came back without, and the fields the record leaves empty because filling them would mean guessing.

It is here rather than at the bottom because a page that only shows what it knows is easy to read as a page that knows everything. For Shorthead redhorse there are 22 of them.

Named by a reviewer

19

Somebody looked for this and wrote down that they did not find it.

Behaviour

Nobody has sourced:

  • diel activity pattern — no primary source found
  • winter habitat and overwintering behaviour — no primary source found
  • cold-front / barometric response — no primary source found
  • water-level and flow-change response with primary-source support
  • angling-pressure response — no primary source found
  • cover use and predator avoidance — the accounts reviewed describe substrate and current association only
  • non-spawning social structure (school vs. loose association)
Identification

Nobody has sourced:

  • juvenile and young-of-year appearance — not described in the agency accounts reviewed
  • regional colour variation and any spawning colour change beyond male tubercles
  • a typical (rather than maximum) weight from a primary source
  • current taxonomic limits of Moxostoma macrolepidotum relative to closely related redhorse forms were not resolved from the sources reviewed; treat the record as the broad, widely used concept
Forage

Nobody has sourced:

  • direct dietary confirmation of mollusks for this species was not found in the sources reviewed; the catalog forage class is retained but is not independently verified here, and note that shorthead pharyngeal teeth are slender and comb-like rather than the molar, shell-crushing type carried by river redhorse
  • young-of-year and juvenile diet — not described in the sources reviewed
  • season-by-season diet shifts — not described in the sources reviewed
  • prey-size shifts with growth
Season

Nobody has sourced:

  • winter entry omitted — no sourced description of overwintering habitat or activity
  • depth tendency by season — not described in the sources reviewed
  • light sensitivity / diel pattern — not described in the sources reviewed
  • stillwater (lake and reservoir) seasonal use, which state accounts confirm occurs but do not describe

Absent from the record

3

No reviewer wrote a gap here. The field is simply empty, which is its own answer.

Water temperature

No agency or peer-reviewed temperature band for Shorthead redhorse was found that a review would accept. The reading runs without one rather than borrowing a number from a related fish.

Identification

No reviewed image. A photograph is only in this catalog when an agency or a named creator labelled the subject, and nobody has cleared one for this species yet.

Population context

No regional population profile is registered. The species-level reading stands on its own; it does not silently become a local one.

Where the record puts it

Water and range

Broadly distributed across Mississippi, Great Lakes, St. Lawrence, Hudson Bay, and connected central/eastern river systems.

Flowing water

5 reviewed holding classes
  • Riffle-to-run transition
  • Run
  • Pool tail
  • Current break
  • Deep pool

Stillwater

4 reviewed holding classes
  • Rocky shoreline
  • Drop-off
  • Inlet
  • Shallow flat

DepthBottom-oriented in runs and pools, moving onto shallower gravel during seasonal spawning movement.

Moving waterMost abundant in medium to moderately large rivers with strong flow and extensive clean sand, gravel, and rubble; can also use pools in smaller streams.

LightBenthic feeding makes substrate and current more important than light; bright clear conditions can reinforce depth.

Thermal band

Temperature

No reviewed temperature band

Nobody publishes a preferred or active temperature range for Shorthead redhorse that a review would accept. Borrowing one from a related fish would look like knowledge and behave like a guess, so the reading runs without it and says which parts of the answer that weakens.

How it uses water

Behaviour

This dossier is marked partial. It holds what was sourced and stops where the sourcing did.

Outside the spawning period the sources reviewed describe co-occurrence with other redhorse and stream fishes in the same current-swept habitat rather than a defined school. Aggregation at spawning time is documented but is conservation context only. The non-spawning social structure is not resolved by the sources reviewed.

A benthic invertivore. The sub-terminal, downward-facing sucking mouth is built to work the bottom, and a review of the genus found gut contents dominated by mayflies (53%), caddisflies (24%), chironomids (10%) and crustaceans (8%), with 46% of gut content by volume being sediment — that is, prey taken with a mouthful of substrate rather than picked out of the drift.

Recorded as a non-claim. No agency or peer-reviewed source reviewed here resolves a diel activity pattern for this species; 'mixed' is entered because the field is required, and the gap is listed rather than filled with a guess.

Seasonal activityAdults make a spring migration out of larger rivers into smaller rivers and streams; a review of the genus describes spring migration to coarse-substrate, fast-running water as the shared Moxostoma pattern. Autumn and winter movement was not resolved by the sources reviewed.

Temperature-driven behaviourHabitat accounts place the species in rivers of intermediate temperature. Reproductive activity begins near 14°C (57°F) and is sustained to about 22°C (72°F); Minnesota records spawning across 8–16°C. The upper lethal limit is reported at 33.3°C and the critical thermal maximum at 35.1°C, so the catalog's 55–70°F band sits well inside the species' tolerance rather than at its edge.

Facing the currentAssociated with strong current. State accounts place it in medium-sized to moderately large rivers with strong flow and substantial areas free of silt, and Montana specifically with the shallow, swift water of larger rivers.

ClarityTolerant across clear to moderately turbid water, but tied to sand, gravel or rock bottom without heavy silt deposition. Iowa classifies it as a species of intermediate pollution tolerance.

Spawning (conservation context)Spring spawner over coarse rubble in shallow, moderate-to-fast flowing water; adults move from larger rivers into smaller rivers and streams to do it. Reported spawning temperatures run from about 8°C to 22°C depending on latitude, with initiation near 14°C. Fecundity is reported at roughly 12,000–45,000 eggs per female, with no parental care. Spawning substrate and any spawning-period concentration are excluded from target guidance.

Where the general rule stops

  • Do not convert spring tributary migrations into aggregation recommendations.
  • Redhorse identification matters; similar sucker species can carry different conservation status.

What it can eat

Forage

A capacity list, not a report from this week. What is actually available on your water is a separate question, and Hatch Match is the tool that asks it.
  • Aquatic insects
  • Mollusks
  • Crustaceans
  • Worms / annelids

Predominantly immature aquatic insects gleaned from the bottom — a review of the genus found mayflies at 53%, caddisflies at 24% and chironomids at 10% of gut contents, and Minnesota calls this the most insectivorous of its suckers. Crustaceans made up about 8% (water fleas, copepods and amphipods are named in state accounts) and worms are also taken. Nearly half the gut content by volume was sediment, which is what a substrate-vacuuming feeding mode looks like. Capacity is not a current hatch.

Feeding style
Opportunistic
Feeding zone
Benthic

By life stage

Adult
Benthic invertivore: immature midges, mayflies and caddisflies taken off and within the bottom, plus small crustaceans and worms.

Diet capacity is not proof that a hatch or prey event is occurring. Observed current forage still comes from a user observation or Hatch Match.

Through the year

Season

A current-and-substrate fish rather than a cover fish: medium-to-large rivers with strong flow, sand-gravel-rock bottom and little silt, worked from below by a downward-facing sucking mouth. Spring brings a movement out of larger rivers into smaller flowing water, which is conservation context. Autumn and winter habitat use is not resolved by the sources reviewed, and no entry is written for winter.

Spring

Where they sit
Riffle-to-run and run over clean gravel, rubble and rock in medium-to-large rivers, and the same water in the smaller rivers and streams adults move into.
Movement
Adults move from larger rivers into smaller rivers and streams as water warms.
Feeding
Bottom-worked immature insects; feeding is a substrate activity, not a drift-interception activity.
Temperature
Reproductive activity begins near 14°C (57°F); Minnesota records the spawning window across 8–16°C, running from late April in the south to early June in the north.
Current
Moderate to fast flow over coarse substrate.

What that changesBottom-contact drift and tight-line drift keep an offering on the substrate where this species actually feeds; stationary bait is the other reviewed flowing family that matches a bottom-oriented invertivore. Surface families do not match the mouth.

What would count against it

  • treating a spring movement into smaller water as a location cue
  • reading the spawning aggregation as holding water

Spring spawner. Spawning substrate and any spawning-period concentration are excluded from target guidance.

Summer

Where they sit
Strong-flow runs, riffle-to-run and pool tails over sand, gravel or rock with substantial silt-free area; current breaks adjacent to that water.
Feeding
Continued benthic invertivory on mayfly, caddisfly and midge immatures.
Temperature
Well inside tolerance through summer — the upper lethal limit is reported at 33.3°C and critical thermal maximum at 35.1°C, far above the catalog's 55–70°F preferred band.
Current
Holds in and beside swift water rather than in slack backwater.

What that changesBottom-contact drift and stationary bait remain the families matched to a downward-facing benthic feeder; tight-line drift covers the same substrate in faster water.

What would count against it

  • fishing it as a mid-column or surface feeder
  • assuming heavy siltation holds the same density of fish as clean gravel

Fall

Where they sit
The same current-swept gravel and rubble runs and pool tails as water cools; no autumn habitat shift is documented in the sources reviewed.
Feeding
Benthic invertivory continues; no seasonal prey switch is described in the sources reviewed.

What that changesBottom-contact drift and tight-line drift; the mechanics do not change because the calendar does.

What would count against it

  • importing a fall-spawning pattern from salmonids — this is a spring spawner

Spawning · Spring

Spring spawning migrations can create dense concentrations on shallow gravel riffles; those concentrations are explicitly not targeting outputs.

Recorded as conservation context. No spawning site, staging concentration or migration bottleneck is named anywhere in this catalog, because naming one is how a population gets fished out.

Telling it apart

Identification

Back and upper sides olive to greenish brown with golden reflections; lower sides a rich golden yellow to yellow-brown; belly white to yellow. Caudal fin red, dorsal fin green or grey.

What to look at

  • Caudal fin is bright red in life. Montana's state key states that no other Montana sucker carries a red tail fin, which makes tail colour the fastest field cut where only one red-tailed redhorse occurs.
  • Rear margin of the lower lip is nearly straight, and the lower lip is broken into parallel folds (plicae) rather than papillae. This straight rear margin is the primary separation from golden and river redhorse, whose lower-lip margin forms a V-shaped angle.
  • Head is short — about 17–19% of total length — the character the common name refers to; other redhorse have proportionally longer heads.
  • Dorsal fin is short, 12–13 rays (12–14 in some state accounts), with a strongly concave, inward-curving outer margin.
  • 41–45 scales in the complete lateral line; body scales are large and even in size front to back, many with a dark crescent-shaped mark at the base.
  • Pharyngeal (throat) teeth are slender and blade-like in a comb-like series, with no flattened molar grinding surfaces.
  • A pea-shaped swelling is often present at the middle of the upper lip (reported as especially common in Ozark specimens).
Average adult length
Adults commonly 300–400 mm (12–16 in); fish over 500 mm (20 in) occur. A Canadian review of the genus puts the species mean near 500 mm TL, so mean length is population-dependent rather than a single figure.
Common angling size
Most fish encountered are in the 12–16 in range; state accounts give an overall adult span of roughly 9–30 in.
Typical weight
Not consistently reported in the agency accounts reviewed. Montana gives a state maximum near 5 lb, which brackets the upper end rather than describing a typical fish.
Maximum documented
State accounts give a length span to about 30 in; Montana reports fish to roughly 5 lb. A single continent-wide maximum was not found in the sources reviewed.
Longevity
Commonly 8–10 years, occasionally 12 or more; a review of the genus gives a mean lifespan near 11 years and notes this is the shortest-lived of the redhorses.

What it gets confused with

Golden redhorse (Moxostoma erythrurum)
Golden redhorse has the rear margin of the lower lip forming a V-shaped angle; shorthead's rear lip margin is nearly straight. Golden redhorse also has a proportionally longer head than the shorthead's 17–19%-of-total-length head.
River redhorse (Moxostoma carinatum)
River redhorse also has a bright red tail, so tail colour will not separate them. Use the mouth: river redhorse has few, broad, molar-like pharyngeal teeth with flat grinding surfaces (a shell-crusher) and a slight V-angle to the rear lip margin, and its dorsal margin is straight to slightly convex. Shorthead has comb-like slender teeth, a nearly straight rear lip margin, and a strongly concave dorsal margin.
White sucker
White sucker has fine scales that are largest near the tail and get smaller toward the head, and lips covered in small bumps (papillae). Shorthead redhorse has large, evenly sized scales over the whole body and plicate (folded) lips, plus the red tail.
Northern hog sucker (Hypentelium nigricans)
Northern hog sucker has a large, square, bony head that is concave between the eyes and usually four dark crossbars over the body. Shorthead redhorse has a small rounded head and no crossbars.

What follows from all of that

Presentation families

These are the families the record will consider for this fish, and what each one has to do. They are not ranked here — ranking needs a season, a temperature and a piece of holding water, which is what the reading is for.

Flowing water

Bottom-contact drift

Tick or crawl a food form along the substrate through a feeding lane without snagging constantly.

  • feel the bottom
  • short hops
  • reset after hang
  • weight just enough
What it asks of the tackle
Depth control
High
Sensitivity
High
Casting distance
Moderate
Weight range
1/8–3/8 oz
Cover resistance
Moderate
Line visibility
Low
Retie frequency
Moderate

Dead drift

Allow a food-form imitation to move at or near current speed through a defined feeding lane.

  • controlled depth
  • minimal drag
  • short-to-medium presentation lane
  • occasional repositioning
What it asks of the tackle
Depth control
High
Sensitivity
High
Casting distance
Short to moderate
Weight range
1/64–1/8 oz or unweighted fly
Cover resistance
Low
Line visibility
Low
Retie frequency
Moderate

Stationary bait

Hold a scent or food form in one feeding station and wait for a fish to move to it.

  • anchor the presentation
  • keep bait in the pocket
  • detect takes without sweeping
  • refresh often
What it asks of the tackle
Depth control
High
Sensitivity
Moderate
Casting distance
Short
Weight range
1/4–1 oz
Cover resistance
High
Line visibility
Moderate
Retie frequency
High

Stillwater

Bottom contact

Keep a bait on or just above the substrate along a break, flat, or inside a weed edge.

  • feel bottom
  • drag or hop
  • pause on the break
  • stay in contact
What it asks of the tackle
Depth control
High
Sensitivity
High
Casting distance
Moderate
Weight range
1/8–1/2 oz
Cover resistance
High
Line visibility
Low
Retie frequency
High

Slow drag

Move a bait along the bottom slowly enough that it stays in the feeding layer of inactive fish.

  • continuous contact
  • very slow travel
  • pause at changes in bottom
  • do not hop out of the zone
What it asks of the tackle
Depth control
High
Sensitivity
High
Casting distance
Moderate
Weight range
1/8–3/8 oz
Cover resistance
Moderate
Line visibility
Low
Retie frequency
Moderate

What moves them for this fish

Reviewed rules that push particular families up when the conditions match. Each one names the conditions it needs and why it exists, so you can disagree with it.

  • Shorthead redhorse are clean-substrate benthic feeders; reinforce bottom/current mechanics outside spring spawning aggregations.

    When

    Riffle-to-run transition, Run, Pool tail, Current break, Deep pool, Rocky shoreline, Drop-off · Aquatic insects, Mollusks, Crustaceans, Worms / annelids

    Moves up

    Bottom-contact drift, Dead drift, Stationary bait, Bottom contact, Slow drag

    Reviewed 2026-08-27

Where every sentence came from

Sources

Reviewed 2026-08-27, next review 2026-11-27. Each entry says which part of the page leans on it, so you can check the claim you care about rather than the whole list.
  1. Agency

    Missouri Department of Conservation — Field Guide: Shorthead Redhorse

    Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-23.

  2. Agency

    Illinois Department of Natural Resources — Wild About Fishes: Shorthead Redhorse

    Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-23.

  3. Agency

    Montana Field Guide (Montana Natural Heritage Program / Montana Fish, Wildlife & Parks) — Shorthead Redhorse

    Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-23.

  4. Agency

    Iowa Department of Natural Resources BioNet — Shorthead Redhorse species overview

    Used for behaviour; forage; season. Read 2026-08-30, next check 2026-12-11.

  5. Agency

    Missouri Department of Conservation shorthead redhorse field guide

    Used for habitat, thermal band and presentation families. Read 2026-08-27, next check 2026-11-27.

  6. Agency

    Minnesota river-fish habitat synthesis for redhorse species

    Used for habitat, thermal band and presentation families. Read 2026-08-27, next check 2026-11-27.

  7. Agency

    Missouri Department of Conservation — Field Guide: River Redhorse (comparative characters)

    Used for identification. Read 2026-08-30, next check 2026-11-23.

  8. Agency

    Missouri Department of Conservation — Field Guide: Golden Redhorse (comparative characters)

    Used for identification. Read 2026-08-30, next check 2026-11-23.

  9. Agency

    Missouri Department of Conservation — Field Guide: White Sucker and Northern Hog Sucker (comparative characters)

    Used for identification. Read 2026-08-30, next check 2026-11-23.

  10. Peer reviewed

    Biology and Conservation of Moxostoma spp. Occurring in Canada (review, Fishes 2025)

    Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-23.

A source with no link predates the rule that one has to carry a URL. It is still a real citation and still checkable; it just takes a search rather than a click, and that is worth knowing before you rely on it.