Listen&Learn: Deep-sea gigantism

Learn why animals that live in deep water grow so large.

Pre-listening vocabulary

• phenomenon: a natural occurrence, especially a mysterious or unexplained one
• colossal: very large
• metabolism: the process of producing energy from food
• conserve: to limit the use of a resource so it isn’t wasted
• mature: to develop into an adult

Listening activity

Podcast: Play in new window | Download (Duration: 1:11 — 1.1MB)

Subscribe: Apple Podcasts | Google Podcasts | RSS | More

Gapfill exercise

Sea creatures that live in the of the ocean can sometimes grow much bigger than similar creatures that prefer waters. This is a phenomenon called deep-sea gigantism. A well-known example of deep-sea gigantism is the colossal , which can grow up to 14 metres long. There are several theories about the causes of deep-sea gigantism. It is believed that the colder at the bottom of the ocean can slow an animal’s metabolism. This is important for the of deep-sea creatures. Food can be hard to find in the cold, dark water, which means that these creatures have to conserve their energy. With such slow metabolisms, they take a long time to mature. This allows them to continue growing.

Comprehension questions

See answers below

1. Gigantism occurs
   a. in warm water
   b. in water with high salt levels
   c. in deep water
   
2. Deep-sea creatures have slower metabolisms because of
   a. the temperature of the water
   b. the lack of light
   c. the nutrients in the food
   
3. These animals grow larger because
   a. they eat more food
   b. they have more time to mature
   c. they need to look like predators

Discussion/essay questions

1. Scientists have only explored about 5% of the oceans. What else do you think they might discover in the future?

Transcript

Sea creatures that live in the depths of the ocean can sometimes grow much bigger than similar creatures that prefer shallow waters. This is a phenomenon called deep-sea gigantism. A well-known example of deep-sea gigantism is the colossal squid, which can grow up to 14 metres long. There are several theories about the causes of deep-sea gigantism. It is believed that the colder temperatures at the bottom of the ocean can slow an animal’s metabolism. This is important for the survival of deep-sea creatures. Food can be hard to find in the cold, dark water, which means that these creatures have to conserve their energy. With such slow metabolisms, they take a long time to mature. This allows them to continue growing.

Answers to comprehension questions

1c 2a 3b