PATTERNS OF SURVIVAL, GROWTH AND MATURATION IN TURTLES

A review of published data suggests that turtles (Order Testudines) re semble other previously studied Vertebrate and invertebrate groups in terms of the relationships among growth trajectories, adult survival r ates, and ages at maturation. For example, most turtles mature at arou nd 70% of maximum size, as do other reptiles. Adult lifespans are prop ortional to age at maturity, and the relationship between these two va riables is similar in turtles to that documented in other reptiles. Al though the ratio of the von Bertalanffy growth constant (k) to the adu lt instantaneous mortality rate (M) appears to be higher than ratios r eported for other animals (including squamate reptiles), the general r elationship between these two variables corresponds with that seen in other reptiles. These analyses show that turtles exhibit patterns of g rowth, survivorship and maturation that are of the same form as those that are present in other types of organisms in which growth continues after maturity.