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Cell fate studies have revealed that also the overall temporal sequence in which groups of endomesodermal cells internalize along the frog blastopore and amniote primitive streak are surprisingly similar: the first cells that involute around the amphibian blastopore lip in the organizer region, and that immigrate through Hensen's node ...
The skin colour of amphibians is produced by three layers of pigment cells called chromatophores. These three cell layers consist of the melanophores (occupying the deepest layer), the guanophores (forming an intermediate layer and containing many granules, producing a blue-green colour) and the lipophores (yellow, the most superficial layer).
The largest part of it is a special structure called the valvula, which has an unusually regular architecture and receives much of its input from the electrosensory system. [ 66 ] Most species of fish and amphibians possess a lateral line system that senses pressure waves in water.
X-ray showing the skeleton of Typhlonectes (Typhlonectidae). Caecilians' anatomy is highly adapted for a burrowing lifestyle. In a couple of species belonging to the primitive genus Ichthyophis vestigial traces of limbs have been found, and in Typhlonectes compressicauda the presence of limb buds has been observed during embryonic development, remnants in an otherwise completely limbless body. [7]
Cell movements during amphibian gastrulation. In frog embryos, gastrulation initiates at the site identified as the gray crescent, located on the future dorsal side of the embryo, slightly below the equatorial region. This process involves cells migrating inward to form a structure similar to a blastopore.
The majority of amphibians use cutaneous respiration, or the process of breathing through the skin. Due to the importance of the skin, amphibians are very sensitive to what goes through their permeable skin, the stratum corneum is the main skin barrier which is much thinner than other classes such as mammals or birds.
Both the Joseph cells and Hesse organs are in the neural tube, the Joseph cells forming a dorsal column, the Hesse organs in the ventral part along the length of the tube. The Joseph cells extend from the caudal end of the anterior vesicle (or cerebral vesicle) to the boundary between myomeres three and four, where the Hesse organs begin and ...
The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including mollusks, crustaceans, insects, fish, and amphibians.