Editing Transparency and translucency (section)

== As camouflage ==

[[File:Expl0469 - Flickr - NOAA Photo Library.jpg|thumb|upright|Many animals of the open sea, like this ''[[Aurelia labiata]]'' jellyfish, are largely transparent.]]

{{Further|List of camouflage methods}}

Many [[Sea|marine]] animals that float near the surface are highly transparent, giving them almost perfect [[camouflage]].<ref name=HerringTransparency>Herring, Peter (2002). ''The Biology of the Deep Ocean''. Oxford University Press. {{ISBN|978-0-19-854956-7}}. pp. 190–191.</ref> However, transparency is difficult for bodies made of materials that have different [[refractive index|refractive indices]] from seawater. Some marine animals such as [[jellyfish]] have gelatinous bodies, composed mainly of water; their thick [[Mesoglea|mesogloea]] is acellular and highly transparent. This conveniently makes them [[buoyancy|buoyant]], but it also makes them large for their muscle mass, so they cannot swim fast, making this form of camouflage a costly trade-off with mobility.<ref name=HerringTransparency/> Gelatinous [[plankton]]ic animals are between 50 and 90 percent transparent. A transparency of 50 percent is enough to make an animal invisible to a predator such as [[cod]] at a depth of {{convert|650|m|ft}}; better transparency is required for [[invisibility]] in shallower water, where the light is brighter and predators can see better. For example, a cod can see prey that are 98 percent transparent in optimal lighting in shallow water. Therefore, sufficient transparency for camouflage is more easily achieved in deeper waters.<ref name=HerringTransparency/> For the same reason, transparency in air is even harder to achieve, but a partial example is found in the 
[[glass frog]]s of the South American rain forest, which have translucent skin and pale greenish limbs.<ref>{{cite web|last=Naish|first=D.|title=Green-boned glass frogs, monkey frogs, toothless toads|url=http://scienceblogs.com/tetrapodzoology/2007/11/09/green-boned-glass-frogs/|work=Tetrapod zoology|publisher=scienceblogs.com|access-date=14 February 2013|url-status=live|archive-url=https://web.archive.org/web/20121111125205/http://scienceblogs.com/tetrapodzoology/2007/11/09/green-boned-glass-frogs/|archive-date=11 November 2012}}</ref> Several Central American species of clearwing ([[Ithomiini|ithomiine]]) butterflies and many [[dragonfly|dragonflies]] and allied [[insect]]s also have wings which are mostly transparent, a form of [[crypsis]] that provides some protection from predators.{{Citation needed|date=April 2021}}