A) They can provide food for certain species. B) They filter pollutants from water. C) They eliminate oxygen from water. D) They act as predators to most fish.
A) Cold water currents B) High pH levels C) Reduced salinity D) Eutrophication
A) Open ocean B) Coastal areas C) Freshwater lakes D) High mountain streams
A) They have a slow growth rate. B) They require complex mating rituals. C) They migrate during breeding season. D) They can reproduce both sexually and asexually.
A) The mature, free-swimming stage of jellyfish. B) The polyp stage of jellyfish. C) The larvae stage of jellyfish. D) A type of jellyfish predator.
A) The Arctic Ocean B) Lake Baikal C) The Amazon River D) The Black Sea
A) Radioactive tagging B) Satellite tracking C) Underwater sound monitoring D) Airborne surveys
A) Their thick gelatinous bodies B) Their ability to swim against strong currents C) Their strong propulsion ability D) Their ability to drift with currents |