Benthos and benthic both refer to living on or under the substrate at the bottom of the ocean. Sessile means the organism is attached to the substrate. Pelagic refers to living in the water of the ocean above the bottom. Pelagic organisms usually have some ability to move around.
Any of a diverse group of aquatic plants and animals that lives on the bottom of marine and fresh bodies of water. The presence or absence of certain benthic organisms can be used as an indicator of water quality.
Growing or living on or near the bottom of an aquatic system. Benthic invertebrates are small animals without backbones living on the bottom of a lake or river; for example clams and mayfly nymphs. [Gk. benthos, depth of the sea.
A term that applies to those things or organisms that live on the bottom floor of a body of water. Caddysflies and stoneflies are benthic macroinvertebrates because they live crawling on the bottom of a river among rocks and gravel.