Claudius angustatus

Geographic Range

Narrow-bridged musk turtles are found surrounding the Gulf of Mexico, occupying Mexico, Guatemala, and Belize.

• Biogeographic Regions
• nearctic nearctic
  • native native
• neotropical neotropical
  • native native

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 tropical
• terrestrial terrestrial
• freshwater freshwater

• Terrestrial Biomes
• forest forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• temporary pools
• coastal coastal

• Wetlands
• swamp 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 ectothermic
• bilateral symmetry 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 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 seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous 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 natatorial
• motile motile
• solitary 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.

• Perception Channels
• visual visual
• acoustic acoustic

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 carnivore
  • insectivore insectivore
  • eats non-insect arthropods
  • molluscivore molluscivore
• herbivore herbivore
  • eats sap or other plant foods
• omnivore 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.

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.

• Positive Impacts
• pet trade pet trade
• food food

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 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

Encyclopedia of Life

Contributors

Madeline Salomon (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

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