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These land snails have opercula, which helps identify them as "winkles gone ashore", in other words, snails within the clade Littorinimorpha and the informal group Architaenioglossa. Members of the snail family Pulmonata , which includes carboniferous land sails and some freshwater snails of the order Basommatophora , are protandrous ...
The freshwater snail Physa acuta is a self-fertile organism that can be exposed either to strong sexual selection or to self-fertilization depending on its mode of reproduction. Noel et al. [ 29 ] used Physa acuta to experimentally determine whether accumulation of deleterious mutations is avoided by inbreeding populations of the snail, as well ...
This is because in asexual reproduction a successful genotype can spread quickly without being modified by sex or wasting resources on male offspring who will not give birth. Some species can produce both sexually and through parthenogenesis, and offspring in the same clutch of a species of tropical lizard can be a mix of sexually produced ...
The anatomy of a common air-breathing land snail: much of this anatomy does not apply to gastropods in other clades or groups. Snails are distinguished by an anatomical process known as torsion, where the visceral mass of the animal rotates 180° to one side during development, such that the anus is situated more or less above the head. This ...
Garden snails mating. A hermaphrodite (/ h ər ˈ m æ f r ə ˌ d aɪ t /) is a sexually reproducing organism that produces both male and female gametes. [1] Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic.
Parthenogenesis is a mode of asexual reproduction in which offspring are produced by females without the genetic contribution of a male. Among all the sexual vertebrates, the only examples of true parthenogenesis, in which all-female populations reproduce without the involvement of males, are found in squamate reptiles (snakes and lizards). [1]
As its Latin name suggests, it is a viviparous (ovoviviparous) snail, a rare phenomenon among snails. The female gives birth to live young, after producing eggs that hatch internally. The female gives birth to live young, after producing eggs that hatch internally.
The female has 17 to 72 embryos in its brood pouch. [4] One female can give life to 62 to 79 newborn snails in the laboratory. [2]The average size of the shell of a newborn snail varies according to the locality from 1.2 to 1.4 millimetres (0.047 to 0.055 in) in width and from 1.9 to 2.1 millimetres (0.075 to 0.083 in) in the height of the shell.