Biometry and Growth of Freshwater Turtle Kinosternon Scorpioides (chelonia: kinosternidae) on Curupu Island, Brazil

Studies on turtle life history are often limited by their extended lifespans. This study investigated the growth patterns and biometric characteristics of Kinosternon scorpioides, a freshwater turtle species, using data collected over a 12-year period on Curupu Island, Maranhão, Brazil. Individuals were captured using traps, permanently marked for individual recognition, and standard biometric measurements—maximum carapace length, plastron length, tail length, body height, carapace width, and body mass—were recorded. Males and females exhibited similar biometric values, with the exception of tail length (greater in males) and carapace width (greater in females). The most frequent plastron length classes were 103 - 111 mm for males and 112 - 120 mm for females. While absolute plastron growth was comparable between sexes, females showed a non-significant trend of greater body mass gain. A negative relationship was observed between the exponential growth rate and the geometric mean body size in both sexes (females: R = –0.54, p < 0.0001; males: R = –0.35, p > 0.05). Growth rates did not significantly differ between sexes. These biometric and growth data likely correlate with reproductive characteristics and provide valuable insights into the ecological dynamics of K. scorpioides. Such findings are crucial for developing effective conservation strategies for the species.