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The eggs of some salamanders and frogs contain unicellular green algae. These penetrate the jelly envelope after the eggs are laid and may increase the supply of oxygen to the embryo through photosynthesis. They seem to both speed up the development of the larvae and reduce mortality. [98]
The family Proteidae is a group of aquatic salamanders found today in the Balkan Peninsula and North America. The range of the genus Necturus (commonly known as waterdogs or mudpuppies) runs from southern central Canada, through the midwestern United States, east to North Carolina and south to Georgia and Mississippi. [1]
Molecular studies of extant amphibians based on multiple-locus data favor one or the other of the monophyletic alternatives and indicate a Late Carboniferous date for the divergence of the lineage leading to caecilians from the one leading to frogs and salamanders, and an early Permian date for the separation of the frog and salamander groups.
Sexual dimorphism is seen as size difference between sexes in salamanders [46] and in 90% of anuran species. [47] Larger females is a result of selection for fecundity, including egg size or clutch size as they can store more energy and produce more offspring. [48] as cited by [41] Females are never more than twice the size of males. [41]
After internal fertilization and the habit of laying eggs in terrestrial environments became a reproduction strategy amongst the amniote ancestors, the next major breakthrough appears to have involved a gradual replacement of the gelatinous coating covering the amphibian egg with a fibrous shell membrane. This allowed the egg to increase both ...
A cross between a toad, Amietophrynus regularis, and a frog, Rana fusca, would not produce a viable embryo, but fertilization of a toad egg by an irradiated frog sperm would produce a haploid larva. [1] Parthenogenesis has also been induced in Pelophylax nigromaculatus by pricking an egg with a needle. [2] This method produced tadpoles which ...
The temnospondyl Eryops had sturdy limbs to support its body on land Red-eyed tree frog (Agalychnis callidryas) with limbs and feet specialised for climbing Japanese giant salamander (Andrias japonicus), a primitive salamander The bright colours of the common reed frog (Hyperolius viridiflavus) are typical of a toxic species Wallace's flying frog (Rhacophorus nigropalmatus) can parachute to ...
A few species deposit eggs on land or bypass the tadpole stage. Adult frogs generally have a carnivorous diet consisting of small invertebrates, but omnivorous species exist and a few feed on plant matter. Frog skin has a rich microbiome which is important to their health. Frogs are extremely efficient at converting what they eat into body mass.