The top predators in most marine food chains are nekton. Which of the following does not belong to the nekton?

Correct answers: (a) Jellyfish or (d) Lobsters

Explanation

Nekton are aquatic animals that swim actively and can move against water currents, such as fishes, sharks, squids, cuttlefish, whales and turtles.

• Jellyfish drift with the currents and are counted among the plankton (zooplankton), so they are not nekton.
• Lobsters mostly crawl on the sea floor and belong to the benthos (bottom-dwellers), so they are not nekton either.

The book's key is (a) jellyfish, which are plankton. Lobsters are bottom-dwellers (benthos), so they are not nekton either, and (d) is also accepted.