Pseudemys peninsularis

Geographic Range

Pseudemys floridana penisularis (Peninsula cooter) is found throughout the Florida peninsula. The northern limit of the range is unknown (Ernst and Lovich 2009; Thomas and Jansen, 2006), though it is assumed that individuals are only found south of Alachua County. Identification of individuals has become challenging due to taxonomic changes and invasion of other floridana sub-species into the range. One study has identified Peninsula cooters in the North and South peninsula, but not the panhandle (Enge, 1997).

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Peninsula cooters occupy any bodies of freshwater found in the range (Thomas and Jansen, 2006), though the primary habitats are floodplain swamps, basin marshes, and occasionally tidal marshes (Enge, 1997). Slow moving or stagnant waterways with abundant basking sites, submerged vegetation, and sandy bottoms are the most preferred (Ernst and Lovich, 2009; Thomas and Jansen, 2006).

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial
• freshwater freshwater

• Aquatic Biomes
• lakes and ponds
• rivers and streams

• Wetlands
• marsh marsh
• swamp swamp

Physical Description

Peninsula cooters exhibit a moderately domed carapace measuring 25-40 cm in length (Thomas and Jansen, 2006), and a plastron measuring 24-35 cm. The carapace is typically dark with light yellow or orange parallel lines. The plastron is unhinged and has an unremarkable, nondescript pattern. The skin is dark with longitudinal yellow stripes around the head and on the neck. Hatchlings have a mid-dorsal keel and are more green in color; however, this changes as the individual matures. All Pseudemys floridana species also do not have a notch in the upper jaw, while most other emydids do.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger

Development

Pseudemys peninuslaris lays eggs diurnally and correlates with rainfall (Thomas and Jansen, 2006). The eggs are retained in the oviducts for less than two weeks; however, captive individuals can retain eggs for up to sixty days and postpone development until the eggs are laid. Type 1A temperature dependent sex determination is seen in this species. The entire clutch hatches within three days, and females can lay up to three clutches per year. Most clutches hatch in the late summer or early fall; however, some clutches will overwinter in nests and hatch in early spring. Hatchlings range in size from 18-33 mm in length.

• Development - Life Cycle
• temperature sex determination

Reproduction

Little is known about the actual mating process of many turtle species, including Pseudemys peninsularis (Thomas and Jansen, 2006). Females reach sexual maturity at 5-7 years old, and males at 3-4 years old, with an average lifespan of 30 years. Females are typically larger than males and have higher domed carapaces, as well as shorter front claws. Tittilation behaviors are thought to represent courtship, but that remains undetermined. Typically, when copulation occurs, the male and female are seen facing the same direction before the male extends his head down towards the female then drops his tail and hind limbs behind the female carapace. The two individuals then sink to the bottom, and researchers presume copulation occurs.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Female peninsula cooters can lay up to three clutches per year (Thomas and Jansen, 2006), with a gestation period of 72 days with the longest documented period being 150 days. Eggs are typically deposited from the oviducts after two weeks; however, under certain conditions, the eggs can be retained for up to 60 days. Nests are built in open sandy areas with light cover with one deep central chamber and two to three satellite chambers. Researchers believe this is done as an anti-predatory tactic. Clutches contain 11-16 offspring. Females reach sexual maturity at 5-7 years, and males are sexually mature at 3-4 years.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous
• sperm-storing sperm-storing

Peninsula cooters do not exhibit parental care or nest guarding. The female is responsible for nest building and egg laying, but after that point, there is no more care given.

• Parental Investment
• no parental involvement

Lifespan/Longevity

Little information is available regarding longevity of the species; however,oon average, peninsula cooters have a life expectancy of 30 years (Congdon and Gibbons, 1989). Growth rates and lifespans are altered by competition with invasive species for food and habitat (Thomas and Jansen, 2006).

Behavior

Little information is described about the behavior of the peninsula cooter. It appears that this is a solitary species, aside from mating. They can be seen basking in small groups, but they do not establish hierarchies. Peninsula cooters can also often be found moving around the habitat, usually guided by resource needs.

• Key Behaviors
• terricolous
• natatorial natatorial
• diurnal diurnal
• motile motile
• solitary solitary

Home Range

Little information is found describing home range of the peninsula cooter. It is believed that they develop relatively large home ranges, which they seldom or never leave.

Communication and Perception

Peninsula cooters use visual and tactile techniques for communication; although, they are occasionally vocal during mating or egg laying. Most tactile and visual communication occurs during mating, when the male performs for the female and uses his claws to touch her head (Thomas and Jansen, 2006).

• Communication Channels
• visual visual
• tactile tactile

• Perception Channels
• visual visual
• tactile tactile
• vibrations vibrations

Food Habits

Pseudemys penisularis is a herbivorous species (Thomas and Jansen, 2006). Adults feed solely on plants and filamentous algae, but some juveniles may eat insects or small fish. Some common diet items include Naias sp., Sagittaria lorata , Lemna sp., filamentous algae, Ceratophyllum sp., Vallisneria americana , Potamogeton illinoisensis , and Hydrilla verticillata (Bjorndal et al. 1997; Marchand, 1942; Thomas, 1972).

• Primary Diet
• herbivore herbivore
  • folivore folivore
  • algivore

• Animal Foods
• fish
• insects

• Plant Foods
• leaves
• wood, bark, or stems
• fruit
• algae

Predation

Adult peninsula cooters have very few predators (otters and alligators); however, a variety of animals prey upon the eggs (Thomas and Jansen, 2006). Because the eggs are so vulnerable, the egg-laying female often builds a series of nests. One nest will contain the majority of the eggs, and the other nests will only contain one or two eggs. This technique is the only well-known anti-predatory technique described.

Ecosystem Roles

It has been established that peninsula cooters are an integral part of the ecosystem, but the full magnitude of how remains unknown (Thomas and Jansen, 2006). Because they appear to be such an integral portion of the ecosystem, scientists have begun referring to peninsula cooters as a keystone species.

• Ecosystem Impact
• keystone species keystone species

Economic Importance for Humans: Positive

Researchs speculate that this species plays an integral role in the ecosystem; however, specific roles are unknown. Often, these individuals are exploited as part of the pet trade because they are easy to care for and maintain.

Economic Importance for Humans: Negative

While peninsula cooters do not actually pose negative effects to humans, there are a few myths that would indicate they do. Many fisherman shoot these individuals because the fisherman are convinced the turtles are killing and eating the game fish. This is inaccurate, because this species is solely an herbivore. A few juveniles eat fish, but only small fish such as minnows. Another people use them as cheap target practice.

Conservation Status

Although the current conservation status of Pseudemys peninsularis is Least Concern, there are still some threats affecting the species. The largest threat is habitat loss and degradation (Ernest and Lovich, 2009; Thomas and Jansen, 2006). The abundant aquatic vegetation found in the habitats is also being rapidly degraded by the invasive Asian Carp ( Ctenopharyngodon idella ). Water edge habitat is also being degraded by human recreational activities, leading to decrease nesting sites. Many individuals are also being exploited as part of the pet trade.

Additional Links

Encyclopedia of Life

Contributors

Ciera McCoy (author), Missouri State University, Brian Greene (editor), Missouri State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Bjorndal, K., A. Bolten, C. Lagueux, D. Jackson. 1997. Dietary overlap in three sympatric congeneric freshwater turtles ( Pseudemys ) in Florida. Chelonian Conservation and Biology , 2: 430-433.

Congdon, J., J. Gibbons. 1989. Freshwater Wetlands and Wildlife . Oak Ridge, Tennessee: U.S. Department of Energy Technical Information Center.

Ernst, C., J. Lovich. 2009. Turtles of the United States and Canada . Baltimore, Maryland: Johns Hopkins University Press.

Marchand, L. 1942. A contribution to the knowledge of the natural history of certain freshwater turtles. M.S. Thesis, University of Florida , 1: 1-27.

Thomas, K. 1972. The annual cycle of reproduction of the emydine turtle, Pseudemys floridana floridana with observations on its ecology. M.S. Thesis, Auburn University , 1: 1-30.

Thomas, R., K. Jansen. 2006. Pseudemys floridana -Florida Cooter. Chelonian Research Monographs , 3: 338-347.

Florida Game and Fresh Water Fish Commission. Habitat Occurrence of Florida's Native Amphibians and Reptiles. Tallahassee, Florida: Kevin Enge-Florida Game and Fresh Water Fish Commission. 1997.