Which tiny crustacean forms a major component of Antarctic zooplankton?

Which tiny crustacean forms a major component of Antarctic zooplankton?

• A. Meroplankton
• B. Macroplankton
• C. Frustule
• D. Krill

Answer: (D)

The main idea is recognizing which organism dominates Antarctic zooplankton as a crustacean. Antarctic zooplankton is heavily built around krill, small shrimp-like crustaceans that occur in enormous swarms. These creatures feed on phytoplankton and in turn are the main prey for many higher predators, from penguins and seals to baleen whales. Their huge biomass and central role in transferring energy from the sun-driven base of the food web up to larger animals make krill a defining component of the Southern Ocean’s zooplankton. Meroplankton refers to organisms that are planktonic only for a part of their life cycle, not a specific crustacean group. Macroplankton describes large planktonic forms, which is about size rather than identifying a particular crustacean. Frustule is the hard silica shell of diatoms, which are phytoplankton, not crustaceans. So krill best fits as the major crustacean component of Antarctic zooplankton.

The main idea is recognizing which organism dominates Antarctic zooplankton as a crustacean. Antarctic zooplankton is heavily built around krill, small shrimp-like crustaceans that occur in enormous swarms. These creatures feed on phytoplankton and in turn are the main prey for many higher predators, from penguins and seals to baleen whales. Their huge biomass and central role in transferring energy from the sun-driven base of the food web up to larger animals make krill a defining component of the Southern Ocean’s zooplankton.

Meroplankton refers to organisms that are planktonic only for a part of their life cycle, not a specific crustacean group. Macroplankton describes large planktonic forms, which is about size rather than identifying a particular crustacean. Frustule is the hard silica shell of diatoms, which are phytoplankton, not crustaceans. So krill best fits as the major crustacean component of Antarctic zooplankton.