التعريف: overall repetitive or reflective pattern in the body of one individual of this taxon. eg: bilateral symmetry, rotational symmetry, radial symmetry
التعريف: aquatic organisms that construct and inhabit simple unbranched vertical shafts with only one opening to the surface. These are primarily above-sediment filter-feeders, surface deposit-feeders, and subsurface deposit-feeders (head-down, conveyor-belt feeders)
التعريف: 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
التعريف: Downward conveyors exhibit a feeding strategy opposite to that of upward conveyors. Vertically oriented head-up feeders actively select and ingest particles at the surface and egest these non-locally as faeces in deeper sediment strata
التعريف: A landform consisting of loose rock particles such as sand, gravel, shingle, pebbles, cobble, or even shell fragments along the shoreline of a body of water.
التعريف: 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)
