Kinematics of level terrestrial and underwater walking in the California newt, Taricha torosa.
نویسندگان
چکیده
Salamanders are acknowledged to be the closest postural model of early tetrapods and are capable of walking both in a terrestrial environment and while submerged under water. Nonetheless, locomotion in this group is poorly understood, as is underwater pedestrian locomotion in general. We, therefore, quantified the movements of the body axis and limbs of the California newt, Taricha torosa, during steady-speed walking in two environments, both of which presented a level surface: a treadmill and a trackway that was submerged in an aquarium. For treadmill walking at a relative speed of 0.63 snout-vent lengths (SVL)/sec, newts used a diagonal couplets lateral sequence walk with a duty factor of 77%. In contrast, submerged speeds were nearly twice as fast, with a mean of 1.19 SVL/sec. The submerged gait pattern was closer to a trot, with a duty factor of only 41%, including periods of suspension. Environment appears to play a critical role in determining gait differences, with reduction of drag being one of the most important determinants in increasing duration of the swing phase. Quantitative analysis of limb kinematics showed that underwater strides were more variable than terrestrial ones, but overall were strikingly similar between the two environments, with joint movement reversals occurring at similar points in the step cycle. It is suggested that the fundamental walking pattern appears to function well under multiple conditions, with only minor changes in motor control necessary.
منابع مشابه
Kinematics of the transition between aquatic and terrestrial locomotion in the newt Taricha torosa.
California newts (Taricha torosa) are capable of locomotion in both aquatic and terrestrial environments. The transition between swimming and terrestrial walking was examined by videotaping individual Taricha walking both up and down a ramp, inclined at 15 degrees to the horizontal, that had its lower end immersed in water and its upper end out of the water. When ascending the ramp, California ...
متن کاملModified Interactions between Salamander Life Stages Caused by Wildfire-induced Sedimentation
A 1993 wildfire and subsequent landslides modified many streams in the Santa Monica Mountains of southern California (USA). Prior to the fire at Cold Creek Canyon, adult California newts (Taricha torosa) frequently preyed on conspecific eggs and larvae. Post-fire landslides increased the number of stream pools containing terrestrial earthworms. Earthworms were more common in adult newt diets af...
متن کاملSex-biased Predation on Newts of the Genus Taricha by a Novel Predator and its Relationship with Tetrodotoxin Toxicity
—Newts of the genus Taricha have long been studied in regards to their skin toxin, tetrodotoxin (TTX). It has been shown that the TTX levels across populations of Taricha are highly variable, and this has been mostly attributed to the interaction between Taricha and their only documented predators, garter snakes of the genus Thamnophis. Here we show that predators other than Thamnophis prey ext...
متن کاملPostcranial myology of the California newt, Taricha torosa.
Salamanders are generally agreed to represent the primitive tetrapod body plan, as well as a postural analog for early tetrapods. Dissection and description of the muscles of the forelimb, trunk, and hindlimb of the California newt, Taricha torosa, were undertaken to provide baseline data on the locomotor structures in this species. Hypaxial trunk muscles are similar to those of other vertebrat...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of experimental zoology. Part A, Ecological genetics and physiology
دوره 311 4 شماره
صفحات -
تاریخ انتشار 2009