Aquatic Life Zones Organisms

Vocabulary flashcards defining the primary types and categories of organisms found in aquatic life zones based on the lecture notes.

Plankton

Weakly swimming, free-floating organisms in saltwater and freshwater life zones that are carried by currents.

Phytoplankton

Plant plankton (from the Greek for drifting plants) and algae that serve as producers supporting most aquatic food chains and food webs.

Zooplankton

Animal plankton (from the Greek for drifting animals) consisting of primary consumers (herbivores) that feed on phytoplankton and secondary consumers that feed on other zooplankton, ranging from single-celled protozoa to large invertebrates such as jellyfish.

Ultraplankton

Extremely small photosynthetic bacteria no more than $2\,\text{micrometres}$ ($40\text{ millionths of an inch}$) wide that are estimated to be responsible for $70\%$ of the primary productivity near the ocean surface.

Nekton

Strongly swimming aquatic consumers, such as fish, turtles, and whales.

Benthos

Bottom-dwelling aquatic organisms, such as barnacles, oysters, burrowing worms, lobsters, and crabs.

Decomposers

Aquatic organisms (mostly bacteria) that break down organic compounds in the dead bodies and wastes of aquatic organisms into simple nutrient compounds.