Search results
Results from the WOW.Com Content Network
Gosner stage 31 tadpole of Nidirana leishanensis. (A) Dorsal view. (B) Lateral view. (C) Ventral view. (D) Mouth structure. [1]Gosner stage is a generalized system of describing stages of embryonal and larval development in anurans (frogs and toads).
Male Dendropsophus microcephalus calling. Sexual selection in amphibians involves sexual selection processes in amphibians, including frogs, salamanders and newts.Prolonged breeders, the majority of frog species, have breeding seasons at regular intervals where male-male competition occurs with males arriving at the waters edge first in large number and producing a wide range of vocalizations ...
As the blastopore deepens, a new embryonic cavity develops, the primitive gut, or the archenteron. It grows in length towards the future front part of the embryo. It can be seen from outside the embryo that the dorsal lip curves itself and grows, creating the side lips of the blastopore. During this time, the paraxial mesoderm enters the embryo.
The embryo during this process is called a gastrula. The germ layers are referred to as the ectoderm, mesoderm and endoderm. In diploblastic animals only the ectoderm and the endoderm are present. [8] * Among different animals, different combinations of the following processes occur to place the cells in the interior of the embryo:
The spotted salamander (Amblystoma maculatum) lives in a symbiotic relationship with a green algae known as Oophila amblystomatis. The algal cells make their way into tissue cells throughout the embryo's body and appears to avoid rejection by activating genes which suppress the embryo's immune response.
Hatching rates for North American salamander species have ranged from 19.5% [10] to 30.5%. [11] It is speculated that intergenomic exchanges, like crossing over during meiosis , may play a role. Intergenomic exchanges are often lethal due to the fact that chromosomes in unisexual species are homeologous (similar, but less so than homologous ...
Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, possibly by brooding and hatching the egg.
They are especially easy to breed compared to other salamanders in their family, which are rarely captive-bred due to the demands of terrestrial life. One attractive feature for research is the large and easily manipulated embryo , which allows viewing of the full development of a vertebrate.