Loggerhead Turtle Research Paper

Loggerhead turtles have many significant adaptations to their current and past environments. Turtles of the family Cheloniidae have various morphological adaptations for aquatic life. Early turtles lost the capacity for aquatic propulsion by body and tail undulations when they developed a shortened, more rigid body form during the Triassic, as an adaptation for armored resistance to attack by predators. However, terrestrial body form with a carapace and walking-type limbs precluded aquatic locomotion and was preadapted for different types of propulsion. In the transition to aquatic life, the shell underwent minimal modifications. These were a lower more streamlined profile and an expansion of the plastrel lobes as an adaptation for swimming rather than walking. The limbs required
greater adaptations including longer hind limbs and more extensive webbing in hind limbs in order to generate a propulsive force. This function is constrained by the need to use hind limbs for nest construction (Pritchard 1997).
The phalanges of forelimbs limbs also became extended, thin, and flattened to gain optimum resistance to water while swimming (Le Buff 1990). This makes the limbs poorly adapted for terrestrial movement; however, because of the importance of aquatic movement in sea turtles, sea turtle species have adapted to have uncompromised adaptations for aquatic locomotion, while evolutionary sacrifices were made for terrestrial locomotion, making movement on land more slow and labored (Pritchard 1997). The loggerhead turtle has a relatively large head and beak compared to other turtles. Loggerhead turtles also have a harder and stronger mandible than other turtle species. This is because it is adapted for it’s foraging behavior of crushing hard bodied organisms such as mollusks. The neck of turtles of the Cheloniidae family is short. All turtle species in this family have lost the ability to completely retract the head and limbs. This is likely due to adaptation to marine existence. The skull of turtles of the Cheloniidae family also provides more protection compared to other turtles (Kamezaki
2003). Additionally, loggerhead sea turtles as well as other sea turtle species have extremities that are adapted to an aquatic habitat. Loggerhead turtles have evolved to have an enlarged flipper and a reduced carapace over time. These are adaptations for long aquatic migrations (Kamezaki 2003). Loggerhead turtles also show morphometric differences among rookeries on different continents. These adaptations occurred over a shorter and more recent timescale and are likely adaptations to the conditions of different ocean basins (Kamezaki 2003). Loggerheads are considered a resilient and adaptable species within their natural environments; however, despite adaptation for survival and function in cold water, they are vulnerable to cold-stunning in areas that normally do not experience extreme cold weather, such as Florida during the freezes in December of 1983 and January of 1985. Turtles that are late to migrate to the south in the fall months may also experience cold-stunning (Dodd 1988).