Definition: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
Definition: Lecithotrophic larvae are provided with a source of nutrition to use during their dispersal, usually a yolk sac. They generally have greater dispersal potential than direct developers, but short pelagic larval durations relative to planktotrophic larvae.
Definition: Capable of creating a new organism by combining the genetic material of two gametes, which may come from two parent organisms or from a single organism, in the case of self-fertilizing hermaphrodites.
Definition: Peabody Museum of Natural History (YPM). New Haven, Connecticut, USA. The Yale Peabody Museum's collections are available to legitimate researchers for scholarly use. Loans are issued to responsible individuals at established institutions. Loans and access to the collection can be arranged through the Collections Manager of the appropriate Division. http://www.peabody.yale.edu/collections/index.html , URL for main institutional website, http://www.peabody.yale.edu/
Definition: A compound eye with no separation between the crystalline-cone layer and the retinula, each rhabdom receiving light only from its own corneal lens.