Medical definition of posterior median sulcus: a shallow groove along the midline of the posterior part of the spinal cord that separates the twoâ¦ a shallow groove along the midline of the posterior part of the spinal cord that separates the two posterior funiculi and is the externalâ¦
Zooplankton Fact Sheet. Zooplankton are microscopic invertebrate animals that swim or drift in water. They are at the base of the food chain, feeding on microscopic plants and being fed upon by aquatic insects, fish and salamanders.ooplankton Fact Sheet. Zooplankton are microscopic invertebrate animals that swim or drift in water. They are at the base of the food chain, feeding on microscopic plants and being fed upon by aquatic insects, fish and salamanders.
An archived version is available as a PDF file. Derived from the Greek words phyto (plant) and plankton (made to wander or drift), phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Some phytoplankton are bacteria, some are protists, and most are single-celled plants.Among the common kinds are cyanobacteria, silica-encased diatoms, dinoflagellates, green algae, and chalk-coated coccolithophores.n archived version is available as a PDF file. Derived from the Greek words phyto (plant) and plankton (made to wander or drift), phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Some phytoplankton are bacteria, some are protists, and most are single-celled plants.