Phrynopus AmphibiaWeb keeps "Noblella" in Strabomantidae/Strabomantinae, a family/subfamily no longer recognized by the Amphibian Species of the World. "Phrynopus" are small to medium-sized frogs, from snout–vent length in "Phrynopus auriculatus" to in "Phrynopus kauneorum". Head is narrower than the body. Differentiated tympanic membrane and tympanic annulus are usually absent, except in "Phrynopus auriculatus" and "Phrynopus peruanus", two basal species. Dorsum is smooth to pustulate. Venter is smooth or areolate. There are 26 species in this genus: Phrynopus Phrynopus is a genus of frogs of the Craugastoridae family. Their common name is Andes frogs. They are endemic to Peru and inhabit the
Biological membrane fatty acid composition in accordance with differing temperatures. In animal cells, membrane fluidity is modulated by the inclusion of the sterol cholesterol. This molecule is present in especially large amounts in the plasma membrane, where it constitutes approximately 20% of the lipids in the membrane by weight. Because cholesterol molecules are short and rigid, they fill the spaces between neighboring phospholipid molecules left by the kinks in their unsaturated hydrocarbon tails. In this way, cholesterol tends to stiffen the bilayer, making it more rigid and less permeable. For all cells, membrane fluidity is important for many reasons. It enables membrane