Apalone muticaLesueur, 1827

Smooth Softshelled Turtle

Photograph by Eric Schmidt, CC BY, via iNaturalist

A water-living, day-active, omnivorous turtle from the Nearctic region, reaching 36 cm across the shell.

Reptilia › Testudines › Trionychidae › Apalone

Grows to: 360mm; greatest recorded
Eats: Omnivorous
Active: Diurnal
Lives up to: 20years

Body length across Trionychidae

Longer than only 11% of all species in Trionychidae anyone has measured.

11% of 28 species are smaller89% larger

230 mmthe whole family, smallest to largest2,000 mm

The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 230 to 2,000 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.

What is known

31 sourced facts, each taken from a named scientific dataset. How to read these.

Cited from a dataset unless a row is marked otherwise.

Standing in the world

Conservation status: Least Concern

The animal itself

Colour on the back: Brown
Pattern on the back: Blotched
Pupil: Round
Venomous: No
Fangs: None
Longest recorded life: 20years

Size

Length nose to tail · greatest recorded: 360mm14 in
Shell length, front to back · greatest recorded: 356mm14 in
Largest female · shell length: 356mm14 in
Largest male · shell length: 178mm7 in
Largest juvenile · shell length: 40mm1.5 in
Body mass · greatestcomputed: 4663g10 lb
Body mass · a typical adult: 819g1.8 lb
Body mass at hatching: 7.06g0.25 oz

How it lives

Diet: Omnivorous
How it hunts: Active foraging
Active: Diurnal
Where it lives: Aquatic
Habitat: Wetlands
Region: Nearctic
Highest it lives · above sea level: 650m

Breeding

Reproduction: Oviparous
Average clutch: 12.2eggs
Eggs or young per clutch: 3–28eggs
Clutches in a year: 2.5per year
Age at first breeding · female: 3285days

Naming and history

Subspecies: Apalone mutica mutica (LESUEUR 1827) Apalone mutica calvata (WEBB 1959)
Described by: Lesueur
Moved to another genus · since it was first described: Yes
Described in: 1827

Keeping one

No enclosure size is given here

The standard sets enclosure size for turtles and tortoises genus by genus, and this genus is not among the roughly sixty it lists. No figure is given rather than one borrowed from a different animal.

No preferred body temperature has been recorded for Smooth Softshelled Turtle. Rather than repeat a number from a care sheet, this page leaves it out.

Feeding

A prey item should be no wider than the space between the animal's eyes.

Widely used across reptile husbandry references. The stated reason is that the gap approximates the width of the throat, so wider prey is associated with impaction. This is established practice, not a measurement.

358kJ per day

Worked out for an animal of 4,663 g, the heaviest recorded for Smooth Softshelled Turtle — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.

An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.

What nobody knows

These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.

— Still living
— Length snout to vent · greatest recorded
— Length snout to vent · adult female mean
— Length snout to vent · adult male mean
— Length snout to vent · adult mean
— Female length · mean, nose to tail
— Length nose to tail · adult male mean
— Length nose to tail · adult mean
— Largest female · snout to vent
— Largest male · snout to vent
— Hatchling length · snout to vent
— Hatchling length · nose to tail
— Largest juvenile · snout to vent
— Egg length
— Egg width
— Body mass · adult female, mean
— Preferred body temperature · chosen in a laboratory gradient
— Body temperature when active · measured in the wild
— Eats arthropods
— Eats vertebrates
— Eats plant matter
— How the young develop
— Gestation or incubation
— Mean clutch · smallest reported
— Mean clutch · largest reported
— Clutches a year · fewest
— Clutches a year · most
— First breeds from · youngest recorded
— First breeds by · oldest recorded
— Hatchling length · smallest recorded
— Hatchling length · largest recorded
— Mature from · youngest recorded
— Mature by · oldest recorded
— Size at maturity · smallest recorded
— Size at maturity · largest recorded
— Body temp in the wild · lowest mean recorded
— Body temp in the wild · highest mean recorded
— Limbs
— Sex decided by
— Status assessed · the year the Red List last looked
— Population trend
— Red List criteria
— Biome
— Active season · shortest recorded
— Active season · longest recorded
— Density · lowest recorded
— Density · highest recorded
— Home range · largest recorded
— Suborder
— Infraorder
— Type locality
— Active in
— Mainland or island
— Lowest it lives · above sea level
— Range size

Others in Trionychidae

Take this data

Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.

This species as JSON · the whole dataset

Cite this page

The Reptile & Amphibian Encyclopedia (2026). Apalone mutica. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/apalone-mutica

@misc{apalone_mutica_2026,
  title  = {Apalone mutica},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/apalone-mutica}
}

Sources

Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
AnAge, Human Ageing Genomic Resources (de Magalhães et al.), used under CC BY 3.0.
Catalogue of Life (dataset 3LR), used under CC BY.
Moura, M. R. et al. TetrapodTraits: a database of 33,281 tetrapod species. Used under CC BY 4.0. Observed values only; this encyclopedia does not publish its imputed predictions.