定義： an animal that excavates holes or tunnels into soil or benthic sediment to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Inhabited burrows function as a refuge, protecting the inhabitants from predation and environmental extremes. They provide physical support for the digging and feeding activities of the burrow inhabitants. The harsh chemical environment deep in aquatic burrows must be counteracted by active or passive irrigation of burrow water.
定義： directly or indirectly modulating the availability of resources to other species, by causing physical state changes in biotic or abiotic materials; modifying, maintaining and/or creating habitats
定義： An organism that moves through the water column via movements of its fins, legs or appendages, via undulatory movements of the body or via jet propulsion; includes pelagic phases during reproduction (swarming at the surface)
定義： A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)
定義： Eye-spots which may be set into a pit to reduce the angles of light that enters, to allow the organism to deduce the angle of incoming light. Lens-like structures may be present, but stemmata, unlike lens eyes, cannot form an image, either for lack of refractive power or retinal resolution.
