Snapping turtles are recognizable reptiles found in freshwater environments across North America. Understanding their growth patterns offers insight into their biology and adaptation to various aquatic habitats.
Snapping Turtle Growth Stages
Snapping turtles begin as small hatchlings, typically measuring 1.1 to 1.5 inches (2.9 to 3.8 cm) in carapace length. Their shells are initially soft, gradually hardening as they mature. Hatchlings grow quickly to increase their chances of survival against predators.
During the juvenile phase (one to five years), growth continues at a noticeable pace, though slower than the initial hatchling burst. By one year, a common snapping turtle can reach 3.5 to 5 inches (8.9 to 12.7 cm) in length. Their shell length can increase to 5.3 to 6.1 inches (13.5 to 15.5 cm) by two to three years old. As they transition into adulthood, their growth rate slows, with more emphasis on increasing body mass.
What Influences Their Growth
Several factors influence the growth rate of snapping turtles. Food availability and quality are primary drivers; a consistent, nutrient-rich diet allows for robust growth. Snapping turtles are opportunistic omnivores, consuming a wide range of prey and plant matter.
Environmental conditions also play a substantial role. Water quality, habitat size, and overall space impact how well a turtle thrives and grows. Temperature is another factor, as these reptiles are ectotherms, meaning their metabolism and growth rate are directly affected by ambient temperatures. Warmer conditions promote faster growth, while cooler climates slow development.
Common Versus Alligator Snapping Turtle Growth
There are notable differences in growth between the Common Snapping Turtle ( Chelydra serpentina) and the Alligator Snapping Turtle ( Macrochelys temminckii). Common snapping turtle adults typically reach a carapace length of 9.8 to 18.5 inches (25 to 47 cm) and weigh between 9.9 to 35.3 pounds (4.5 to 16 kg). Some individuals can grow larger, with the maximum recorded common snapper weighing around 75 pounds.
In contrast, the alligator snapping turtle is the largest freshwater turtle globally. Adults can reach carapace lengths of 31.5 to 39.3 inches (80 to 100 cm) and typically weigh between 154.3 to 198.4 pounds (70 to 90 kg). Exceptional individuals have been recorded weighing up to 249 pounds (113 kg). While both species grow rapidly in their early years, the alligator snapping turtle continues its substantial growth for a longer period, often reaching much greater sizes than its common counterpart.
Reaching Full Size and Maturity
Snapping turtles generally reach sexual maturity between 8 to 10 years of age, though this can vary with environmental factors and geographic location. For common snapping turtles, sexual maturity can occur around 4 to 6 years for males and 10 to 12 years for females, with carapace lengths of about 7 to 8 inches (18 to 22 cm). Alligator snapping turtles typically reach maturity between 11 to 13 years old.
While sexual maturity marks a significant milestone, snapping turtles continue to grow throughout their lives, albeit at a significantly slower rate. Growth after maturity primarily contributes to an increase in weight rather than dramatic changes in shell length. Common snapping turtles may take 15 to 20 years to approach their maximum size, while the larger alligator snapping turtles can continue growing for over 30 years. Their potential lifespan is considerable, with common snapping turtles living up to 30-40 years in the wild, and some individuals potentially exceeding 100 years. Alligator snapping turtles can live up to 45 years in the wild and even longer in captivity, with some documented living over 70 years.