Tadpoles of Xenopus laevis reared in water containing 0-01% propylthiouracil continue to grow but fail to develop or metamorphose. The haemoglobin of such tadpoles has been extracted in buffer, converted to a cyanmet form, and run on polyacrylamide gels. The developmentally retarded tadpoles are found to possess adult-type haemoglobin rather than the tadpole type which normally characterizes th...

The effects of acute and developmental temperature on maximum burst swimming speed, body size, and myofibrillar ATPase activity were assessed in tadpoles of the Pacific tree frog, Hyla regilla. Tadpoles from field-collected egg masses were reared in the laboratory at 15 degrees (cool) and 25 degrees C (warm). Body size, maximum burst swimming speed from 5 degrees to 35 degrees C, and tail myofi...

Biotic factors such as body size and shape have long been known to influence kinematics in vertebrates. Movement in aquatic organisms can also be strongly affected by abiotic factors such as the viscosity of the medium. We examined the effects of both biotic factors and abiotic factors on buccal pumping kinematics in Xenopus tadpoles using high-speed imaging of an ontogenetic series of tadpoles...

Xenopus laevis tadpoles that arrest development and remain as larvae for several years sometimes occur spontaneously in laboratory populations. These tadpoles cease development at an early hindlimb stage, but continue to grow and develop into grossly deformed giants. Giant tadpoles lack thyroid glands, and differ in morphology and behaviour from normal larvae. They are negatively buoyant, typic...

Amphibians, widely studied as environmental indicators, facilitate the transfer of nutrients between aquatic and terrestrial habitats. To examine the role of amphibians in nutrient cycling, I studied bullfrog (Rana catesbeiana) tadpoles in an artificial stream environment. I hypothesized that the presence of tadpoles would decrease algal stock biomass and sedimentation but increase chlorophyll ...

heavy metal pollution plays an important role in global biodiversity decline. however, there is paucity of information concerning the effects of metals on amphibians. in the present study, investigations were made on the accumulation of heavy metals, copper (cu) and lead (pb) in water, sediment and tadpoles inhabiting the water bodies of barak valley, assam. tadpoles of six different anuran spe...

The characteristics of microhabitats in streams can drive the distribution tadpoles. We experimentally examined microhabitat selection tadpoles Dryophytes plicatus . used a series choice experiments to test if had preferences for particular substrate types, colors, and vegetation. Tadpoles D. strong preference mud substrates over sand, gravel, rock preferred darker lighter substrates. non-veget...

Though light conditions are known to affect the development and anti-predation strategies of several aquatic species, relatively little is known about how different species react to light, or how light can affect these species during different points in their life-cycle. In this study, we used four sympatric anuran tadpoles (Bufo gargarizans, B. melanostictus, Pelophylax nigromaculatus and Micr...