Définition : A taxon is Endangered when the best available evidence indicates that it meets any of the \r\ncriteria A to E for Endangered, and it is therefore considered to be facing a very high risk of extinction in the wild.
Définition : A habitat that is in or on a body of water containing low concentrations of dissolved salts and other total dissolved solids (<0.5 grams dissolved salts per litre).
Définition : A compound eye with no separation between the crystalline-cone layer and the retinula, each rhabdom receiving light only from its own corneal lens.
Définition : A compound eye with no separation between the crystalline-cone layer and the retinula, each rhabdom receiving light only from its own corneal lens.
Définition : superposition compound eyes where each ommatidium is equipped with a set of plane mirrors, aligned at right angles, forming a square. Rays entering the eye at an oblique angle encounter two surfaces of each mirror box rather than one surface. In this case, the pair of mirrors at right angles acts as a corner reflector. Corner reflectors reflect an incoming ray through 180 degrees, irrespective of the ray’s original direction. This ensures that all parallel rays reach the same focal point and means that the eye as a whole has no single axis, which allows the eye to operate over a wide angle.
