Definition: the method used by some animals (e.g. bats, dolphins and some whales) to determine the location of something by measuring the time it takes for an echo to return from it. These animals emit sound waves and listen for the echo, calculating the distance to the object from the time lapse between sound emission and the echo returning.
Definition: The institution that holds a type specimen for a given species. The recommended best practice is to use the identifier in a collections registry such as the Biodiversity Collections Index (http://www.biodiversitycollectionsindex.org/).
Definition: A light sensing organ composed of multiple ommatidia, visual units consisting of a limited number of rhabdomeric photoreceptor cells, cornea-secreting epithelial cells, interommatidial pigment cells, and sometimes crystalline cone cells