Characteristics
- Fish are cold-blooded animals, meaning their body temperature changes with their surroundings. They have gills that extract oxygen from water, and most fish have scales. Fish lay eggs, and their young are called fry.
- Marine mammals are warm-blooded animals, meaning their body temperature is regulated internally. They have lungs that extract oxygen from air, and they give birth to live young. Marine mammals include whales, dolphins, seals, and sea lions.
Habitat:
- Fish can live in a wide range of aquatic environments, including oceans, lakes, rivers, and streams.
- Marine mammals are found in all oceans and some large rivers and lakes. They are most commonly found in coastal waters, but some species, such as whales, can travel long distances across the open ocean.
Reproduction
- Fish reproduce by laying eggs. The eggs are usually fertilized externally, and they hatch into larvae that develop into juvenile fish.
- Marine mammals give birth to live young. The young are born fully developed and are able to swim and feed on their own.
Communication:
- Fish communicate with each other using a variety of sounds and body language. For example, some fish produce clicking sounds to attract mates, while others use body movements to establish dominance or defend their territory.
- Marine mammals also communicate with each other using a variety of sounds and body language. For example, whales use complex vocalizations to communicate over long distances, while dolphins use body movements to express emotions and intentions.
Lifespan:
- Fish have a wide range of lifespans, from a few months to over a hundred years. Some species of fish, such as the Atlantic halibut, can live for over 50 years.
- Marine mammals also have a wide range of lifespans. Some species, such as the bowhead whale, can live for over 200 years.
Conservation status:
- Many species of fish are threatened by overfishing, pollution, and climate change. Some species of fish are considered endangered or critically endangered, and they are at risk of extinction.
- Many species of marine mammals are also threatened by human activities, such as hunting, pollution, and habitat loss. Some species of marine mammals are considered endangered or critically endangered, and they are at risk of extinction.