Belgrandia Varica

	Belgrandia Varica ''Belgrandia varica'' is a species of minute freshwater snail with an operculum, an aquatic gastropod mollusc or micromollusc in the family Hydrobiidae. ''Belgrandia varica'' was previously considered to be extinct,Fontaine B., Bouchet P., Van Achterberg K., Alonso-Zarazaga M. A., Araujo R. et al. (2007). "The European union’s 2010 target: Putting rare species in focus." ''Biological Conservation'' 139: 167-185. Table 2 on the page 173. PDF however it has been classified as Critically Endangered (Possibly Extinct) by IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ... because it might still be present in a small spring that has been overlooked during previous surveys. Distribution This species is endemic to France. References Further reading * Falkner G., Ripke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Animalia Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Operculum (gastropod) The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]