Geographic Range
Narrow-bridged musk turtles are found surrounding the Gulf of Mexico, occupying Mexico,
Guatemala, and Belize.
- Biogeographic Regions
- nearctic
- neotropical
Habitat
Narrow-bridged musk turtles are semi-aquatic, occupying terrestrial and freshwater
areas. They are commonly found in floodplains, semi-permanent water bodies, streams,
swamps, and ponds. They tend to be in hot and humid lowland areas with semi-arid and
dry tropical climates. They live in elevations below 300 meters and occupy small bodies
of water. During the dry season, primarily from March to May, narrow-bridged musk
turtles migrate either underground or in areas with an adequate amount of mud. Then,
during the rainy season which encompasses June to November, they congregate in common
areas in preparation for their courtship and reproduction period.
- Habitat Regions
- tropical
- terrestrial
- freshwater
- Terrestrial Biomes
- forest
- Aquatic Biomes
- lakes and ponds
- rivers and streams
- temporary pools
- coastal
- Wetlands
- swamp
Physical Description
Narrow-bridged musk turtles have an average adult weight of 350-600g, with males tending
to be larger than females. They exhibit sexual dimorphism, with the males being larger
than females and have fastening organs on the hind limbs and tail. There is little
to no information on their metabolic rate and differences in coloring based on gender.
These turtles are identified by sharp maxillary cusps in their upper jaw and large
heads with hooked jaws. They also have webbed digits and a long tail that ends in
a keratinized spine. Their heads and shells are dark in color with some light spots.
Their necks and undersides are more pale gray in color. They do not differ much based
on age, causing their infantile features to be very similar to their adult features.
- Other Physical Features
- ectothermic
- bilateral symmetry
- Sexual Dimorphism
- male larger
Development
Once eggs are fertilized, female narrow-bridged musk turtles will lay their eggs in
areas of vegetation where they then go through an incubation period of 95-229 days
before hatching. Their eggs are ellipsoidal and are produced asymmetrically in the
female. When they hatch, they are about 4.3-7.9g and continue to grow larger. They
are produced in a 1:1 ratio of males to females. They reach sexual maturity at a size
of 89mm for females and 98mm for males. However, they can range rather significantly
in size and reproductive maturity status.
Reproduction
During the rainy season, from June to November, narrow-bridged musk turtles enter
the courtship and reproduction period. This occurs when the narrow-bridged musk turtles
leave their underground nests and seek out mates. Males seem to outnumber females
in the wild, causing them to have to compete for female mates. Males also have larger
mass than females and fastening organs on their rear appendages to assist with mating.
Each season narrow-bridged musk turtles find a mate for that year only, in future
seasons they may find a different individual to mate with.
- Mating System
- monogamous
Narrow-bridged musk turtles reproduce once yearly, with their courting and reproduction
period being from June to November. Female narrow-bridged musk turtles typically have
1-2 clutches per season, with each clutch having 2-8 eggs. The females then lay their
eggs on or within vegetation. There seems to be no preparatory nest building or digging
and they just lay their eggs where they come across vegetation. They are then incubated
for 95-229 days, with an average of 194 days before they hatch. They seem to reach
sexual maturity when females are about 89mm and males are 98mm. It can also be known
when there is a presence of spermatozoa (mature and motile sperm) in males.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
There is limited information about parental investment, however, solely females participate
in caring for the hatchlings. Female narrow-bridged musk turtles don't prepare for
laying eggs by building a nest. Instead they lay their eggs when they come across
a site of vegetation. After that, the eggs take an average of 194 days to mature and
hatch. There is limited information on if the females help and care for them after
hatching.
Lifespan/Longevity
There is limited information on the lifespan of narrow-bridged musk turtles, with
the only known age of one held in captivity being 16.1 years. However, narrow-bridged
musk turtles face threats from illegal hunting, habitat loss and degradation, and
road mortality. They are often hunted for their meat or sold as pets, which decreases
their wild population.
Behavior
Narrow-bridged musk turtles are not very social with other species or within their
own species. As they are solitary creatures, they solely interact with others of their
species during the mating season or by coexisting in shared territory. They are known
to be aggressive towards other species and are commonly found with their mouths open
in a threatening display. Narrow-bridged musk turtles reside in their territory and
venture out to find food in shallow bodies of water.
- Key Behaviors
- natatorial
- motile
- solitary
Home Range
Narrow-bridged musk turtles travel short distances and don't have specific territories
that they defend. During different seasons they do change the type of area they reside
in, however, they do not have a specific range. They also are not territorial as they
can live with others of their own species in the same area.
Communication and Perception
Narrow-bridged musk turtles have developed auditory and visual systems. The auditory
system most likely evolved to be a motion detector. They have otoliths and a tympanic
middle ear, which allows them to detect acceleration and acoustics. They can hear
wavelengths between 100-500 Hz and 35 dB. Their visual system exhibits corneal eyes,
which provides refraction and the deformable lens supports accommodation. They are
not very social and have been reported as hostile towards other species. There is
limited information on how they communicate with other animals.
Food Habits
Narrow-bridged musk turtles are able to puncture and pin their prey with maxillary
cusps or fangs that are on either side of their jaws. They have a varied diet and
eat arthropods, mollusks, tadpoles, frogs, and aquatic vegetation. They also do eat
other smaller turtle species. They eat crustaceans, aquatic insects, and their larvae.
Narrow-bridged musk turtles are not selective with their diet and have been found
to eat meat, fish, shrimps, and worms.
- Primary Diet
-
carnivore
- insectivore
- eats non-insect arthropods
- molluscivore
-
herbivore
- eats sap or other plant foods
- omnivore
- Animal Foods
- amphibians
- insects
- mollusks
Predation
Narrow-bridged musk turtles have glands at the rear of their bodies that give off
a foul scent to ward away predators as a chemical defense. They also have barbels
on their chin and throat, along with a hinge on their shell to enclose themselves
inside for protection. Some of their predators include racoons
Procyon lotor
, skunks
Mephitis mephitis
, birds
Aves
, foxes
Vulpes vulpes
, snakes
Serpentes
, alligators, and occasionally other turtles. Their eggs are targeted more often than
adult bodies and are eaten by many snakes and mammals. As narrow-bridged musk turtles
are a predatory animal, they also partake in cannibalism.
Ecosystem Roles
Narrow-bridged musk turtles are not parasitic and don't use other species as a host.
However, they have been found carrying many organisms including algae and parasites.
They are also predators towards a multitude of small aquatic animals while being prey
to larger aquatic and mammalian species.
- Algae
- trematodes ( Telorchis corti )
- trematodes ( Telorchis patonianus )
- parasitic flatworms ( Herpetodiplostomum delillei )
- parasitic flatworms ( Heronimus chelydrae )
Economic Importance for Humans: Positive
Narrow-bridged musk turtles are hunted for meat consumption and are often captured
to be sold as pets. Humans benefit from both the meat trade and the pet trade, where
narrow-bridged musk turtles are captured and sold throughout the world.
Economic Importance for Humans: Negative
Narrow-bridged musk turtles are commonly used as household pets, causing them to be
bought and sold by humans. They are also known to cause injury to humans by biting
when they are handled. Bites are known to cause salmonella infections as these turtles
carry the bacteria.
- Negative Impacts
-
injures humans
- bites or stings
- causes disease in humans
- household pest
Conservation Status
Narrow-bridged musk turtles are classified as near threatened from their popular use
in trade. They are often captured for meat consumption by humans or killed when crossing
roads. There are also threats from forest loss and degradation that increase their
mortality rate. There are currently no actions to reduce the mortality of narrow-bridged
musk turtles other than attempts to reduce hunting. There is no population estimate
known, however, they are constantly being bred in captivity and sold as pets.
Additional Links
Contributors
Madeline Salomon (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- freshwater
-
mainly lives in water that is not salty.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- swamp
-
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
- monogamous
-
Having one mate at a time.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- natatorial
-
specialized for swimming
- motile
-
having the capacity to move from one place to another.
- solitary
-
lives alone
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- pet trade
-
the business of buying and selling animals for people to keep in their homes as pets.
- food
-
A substance that provides both nutrients and energy to a living thing.
- causes disease in humans
-
an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- molluscivore
-
eats mollusks, members of Phylum Mollusca
- herbivore
-
An animal that eats mainly plants or parts of plants.
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
References
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