FWS Focus

Overview

Characteristics
Overview

The Pearl River map turtle is a member of the genus Graptemys, and like other map turtles, take their name from the intricate map-like pattern on their carapace (top shell). Within this genus is the megacephalic, or big-headed, clade that includes the Alabama, Barbour’s, Escambia, Pascagoula, and Pearl River map turtle. Currently, estimated population size is less than 22,000 turtles left in the wild, which are faced with several threats: 

•    Habitat loss and degradation (i.e., channel and hydrological modifications and impoundments; removal or loss of deadwood; declines in water quality from agricultural run-off; development; and in-stream gravel and sand mining)
•    Future projections to the year 2070 indicate that populations of the Pearl River map turtle may become increasingly isolated due to habitat alteration and in-stream barriers to movement (i.e., low head dams, sills), leading to inbreeding and loss of gene flow. 
•    Sea level rise threatens to reduce available freshwater habitats as saline waters from the Gulf of Mexico encroach into the Pearl River drainage. These effects will be magnified with hurricane-related storm surges into freshwater systems. 
 

There are several ways to help support conservation efforts for this species:
 
•    Support wildlife agencies and conservation organizations in their efforts to conserve this species and learn more about their conservation needs.  
•    Limit offroad vehicle use and disturbance on sand and gravel bars during the nesting season (early May to late July). 
•    Don’t collect or buy turtles that have been collected from the wild. If you suspect illegal collection or distribution of map turtles, report it to the authorities.  
•    Use pesticides responsibly to prevent runoff into aquatic habitats.  
•    Plant trees and other native vegetation to prevent erosion and sediment runoff.
 

Scientific Name

Graptemys pearlensis
Common Name
Pearl River Map Turtle
FWS Category
Reptiles
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

The Pearl River map turtle lives in rivers and large creeks of the Pearl River drainage of Mississippi and Louisiana. They prefer rivers and creeks with swift currents, sand and gravel bottoms, and an abundance of snail and mussel prey. Areas with high densities of deadwood are also required as this provides the structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.

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needed for basking. Deadwood is also necessary for Pearl River map turtle foraging and overnight resting. This species is not found in lakes or floodplain habitats.

River or Stream

A natural body of running water.

Characteristic category

Food

Characteristics
Food

Since adult females develop larger heads and jaws than males, there is a slight variation in diet between sexes. Adult females will consume native mussels and snails, as well as the Asian clam (Corbicula fluminea), which is a significant prey source that makes up a large part of their diet. This is an invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

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and it is likely an alternative food source due to declining native mussel populations. Adult males and juveniles primarily consume aquatic insects, like caddisfly larvae. They will also consume mollusks to a lesser degree than females.

Characteristic category

Physical Characteristics

Characteristics
Color & Pattern

The map turtle takes its name for the intricate map-like pattern on its carapace. The Pearl River map turtle is characterized by a broad light-colored blotch behind and between the eyes, usually with a three-pronged trident shape near the nostrils. This species also has a single vertical bar located near the center of each marginal scute. 

Size & Shape

The megacephalic clade of map turtles have the greatest sexual size difference, with females being twice the length and ten times the weight of males.  Females also have broad heads and jaws made for crushing mollusks, while males have smaller heads and more pronounced vertebral keels. 
 
•    males, 3-5 inches long
•    females, 6-10 inches long
 

Characteristic category

Life Cycle

Characteristics
Reproduction

The Pearl River map turtle nests May through August, with an average clutch size ranging from 6 to 8 eggs. Females likely lay multiple clutches, and hatching occurs July through November. Males become sexually mature at 2 to 3 years of age while females don’t sexually mature until 9 years of age. 

Geography

Characteristics
Range

The Pearl River map turtle inhabits the Pearl River drainage of Louisiana and Mississippi.

Timeline

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