Yellow-Blotched Map Turtle (Gratemys flavimaculata)
Description: Yellow-blotched Map Turtles have distinctive stripes covering their head, neck, and legs. These stripes alternate from yellow to olive green and begin with yellow circles surrounding the eyes, which then extend posterior to the base of the shell. The shells of yellow-blotched sawbacks have orange spots in circular orbits around the shell. They also have tall ridges bisecting the shell on the first four vertebrae. These ridges are black and sometimes are lacking in adult females. The carapace of Yellow-Blotched Map Turtles can be light brown to olive in color.
Yellow-blotched Map Turtles differ in coloration in comparison to other turtles within Graptemys. Ringed Map Turtles (Graptemys oculifera) and black-knobbed map turtles (Graptemys nigrinoda) have a ring on each costal which is light in color and have patterns on their heads that differ from yellow-blotched sawbacks. These two are also lacking in the black vertebrae that are distinctive in yellow-blotched Map Turtles.
Adult females are typically seven to ten times the mass of adult males. The minimum carapace length (CL) of females is 3.15 inches and the maximum CL is 7.1 inches. Males have a CL range of 1.9 to 4.3 inches. The minimum mass of male yellow-blotched sawbacks is 1.75 ounces while the maximum mass is 8 ounces. For females, the minimum mass is 3.3 ounces and the maximum is 41.75 ounces. Males possess longer front claws and thicker tails than females.
At hatching, yellow-blotched sawbacks typically measure 1.17 to 1.35 inches. The minimum mass of juveniles is 12.5g while the maximum is 45g. When these turtles hatch, their markings are generally darker and more defined than full-grown adults. Although the shape and placement of the markings do not change, these markings lighten as the turtles age. Even as juveniles, yellow-blotched sawbacks have vertebrae that come out of the spine on the dorsal side of the shell.
Habitat: Yellow-blotched Map Turtles can inhabit differing widths of rivers, having been found in rivers with widths between 110 and 120m as well as rivers with widths between 65 to 165 feet. They live in reaches of these rivers that contain sandbars for nesting, floating logs for basking, and where the water is exposed to sunlight at some point during the day. The substrates of these rivers are typically sand and silt. Yellow-blotched Map Turtles prefer areas where there is flowing water, but they have been found in stagnant lakes or ponds. In addition to this, they remain in areas where the water stays between 10-35 °C. In warmer weather (June through October), yellow-blotched Map Turtles remain in areas with reduced water flow. In cooler weather (November through May), these turtles tend to remain where there is greater water flow.
Range: Yellow-blotched map turtles (or Yellow-blotched sawback turtles) (Graptemys flavimaculata) are native to rivers of southeastern Mississippi. The main river these turtles inhabit is the Pascagoula River, as well as three tributary rivers: the Leaf River, the Chickasawhay River, and the Escatawpa River. The Leaf River and the Chickasawhay River are both north of the Pascagoula River while the Escatawpa River flows east from the Pascagoula River. The Leaf River flows from the northwest, the Chickasawhay River flows from the northeast, and the Escatawpa River flows from Alabama into Mississippi, feeding into the Pascagoula River.
Found in these States:
MS
Diet: Yellow-blotched map turtles consume sponges, other invertebrates, plants, and algae. The proportions of these can change depending on what is available in the area where these turtles are living; however, the largest portion in volume of diet is sponges: 71% for males and 55% for females. If there are more plants than sponges, they will eat a greater volume of plants without significant effects on their health. Generally, females consume more mollusks than males because they have larger jaws (about 40% more mussels in volume than males). Other animals and plants that these turtles ingest are plant stems, moss, spiders, fruits, seeds, and flowers.
Reproduction: Yellow-blotched Map turtles are polygynadrous. Mating begins underwater when males approach the females while extending their necks forward. Females will face the males and likewise extend their necks. Males will then stroke females’ faces with their claws. Females will attempt to also stroke the males’ faces and necks. It has been reported males biting females on the legs and neck before placing their tails under the females
Yellow-blotched Map turtle females are gravid as early as May and as late as August, but exact gestation period cannot be determined. Nests are also found as early as May and as late as August. It takes an average of 34 minutes for females to build a nest for egg laying. They typically mate once a year but can occasionally mate twice per year. Females dig a nest in which to lay the eggs. The eggs are a creamy white color when laid, as well as slightly pliable. The egg sizes are, on average, 1.45 by 0.9 inches, with an average mass of 0.5 ounces. Clutch sizes are typically three to nine eggs, and hatchlings in nature were observed emerging from their nests in September or October. At hatching, the young are completely independent from both parents. Sexual maturity for males is reached when the plastron length is 2.8 to 3.125 inches, which happens between age 2 to 4. Females are thought to become sexually mature at 8 to 10 years of age.
Status: This species is listed as threatened under the US Endangered Species Act due to a recent decline. This can be attributed to a low reproductive frequency as compared with most other map turtles. A high level of nest mortality due to fish and crow predation and river flooding are also attributed to endangerment. Unexpectedly high occurrences of nesting in shaded areas could possibly be attributed to human disturbances on and near sandbars, which raises mortality rates.
Also, its habitat suffers from pollution and agricultural changes to water levels, affecting nesting beaches. "Turtle plinking", shooting turtles for casual target practice, kills significant portions of this endangered turtle's population each year.
Since yellow-blotched map turtles are freshwater turtles mainly found in the Pascagoula River of Mississippi, human disturbances like an increase in boats in the area of inhabitance, also leads to many physiological issues due to less time to bask or endangerment of the nest.
»» Kingdom: Animalia - Animals
»» Phylum: Chordata - Chordates
»» Subphylum: Vertebrata - Vertebrates
»» Class: Reptilia - Reptiles
»» Order: Testudines - Turtles & Tortoises
»» Family: Emydidae - Pond, Marsh, & Box Turtles
»» Genus: Gratemys
»» Species: Gratemys flavimaculata - Yellow-Blotched Map Turtle
This article uses material from the Wikipedia article "Yellow-Blotched Map Turtle", which is released under the Creative Commons Attribution-Share-Alike License 3.0. Content may have been omitted from the original, but no content has been changed or extended.
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