dolphin quiz

What is a dolphin?

Answer explanation

Dolphins are small-toothed cetaceans easily recognizable by their curved mouths, which give them a permanent “smile.” There are 36 dolphin species, found in every ocean. Most dolphins are marine and live in the ocean or brackish waters along coastlines. There are a few species, however, like the South Asian river dolphin and the Amazon river dolphin, or boto, that live in freshwater streams and rivers.

The largest dolphin, the orca, can grow to be over 30 feet long. The smallest, the Maui dolphin, is just five feet long.

Dolphins feed chiefly on fish and squid, which they track using echolocation, a built-in sonar that bounces sound waves off prey and reveals information like its location, size, and shape. An echolocating bottlenose dolphin can make up to a thousand clicking noises per second.

Behavior and reproduction

Living in pods that can number a dozen or more, dolphins are intensely social mammals that communicate with squeaks, whistles, and clicks. Whether dolphins have language, as humans do, is a topic that scientists have debated for decades.

As mammals, they have warm blood and nurse their young. Dolphins have more than one mate, and generally produce a single offspring that will stay with the mother for up to six years, depending on the species.

Dolphins are graceful, sleek swimmers that can reach speeds of more than 18 miles an hour. They are also playful and often frolic in a boat’s wake, leaping out of the water—possibly for fun, to communicate, or even shed pesky parasites.

Threats

For centuries, people have hunted dolphins for their meat and blubber. Today, their main threat comes from being caught accidentally in commercial fishing nets. Dolphins must rise regularly to the surface to breathe—becoming entangled in nets prevents this, leading to drowning. For maine dolphins, warming ocean temperatures because of climate change have caused some of their primary food sources to move into deeper, cooler water. Furthermore, marine heatwaves, also caused by climate change, appear to have a negative affect on dolphins' reproductive rates and ability to survive.

In addition to hunting and entanglement in fishing gear, freshwater dolphins face the additional threat of dams fragmenting and degrading habitat.

Do dolphin eat turtules

• yes

• no

Answer explanation

There are more than forty species of dolphin and they live in environments ranging from freshwater rivers, estuaries, and coastal waters to deep sea open oceans. Most dolphins are opportunistic feeders, which means they eat the fish and other animals sharing their homes.  All dolphins eat fish and those living in deep oceans also eat squid and jellyfish.

Bottlenose dolphins are found worldwide in temperate and tropical seas and the types of fish they eat, is dependent on where they live and what time of year it is. Bottlenose dolphins living in the Moray Firth, Scotland, favour salmon when it is available in the spring and summer months. In the winter, salmon is scarce, and so they eat herring and mackerel. Bottlenose dolphins living elsewhere eat their favoured local fish which can be mullet, mackerel, catfish and more tropical species of fish. All dolphins have teeth but they don't chew their food, they just, grab, bite and swallow!

Amazon river dolphins are known to eat more than 40 different species of freshwater fish and they also eat freshwater crustaceans. Spinner dolphins eat fish, jellyfish and krill. Dusky dolphins eat shrimp, squid and various fish, including tiny anchovies. Rough-toothed dolphins live in deep water oceans and eat mostly squid. Commerson’s dolphins feed on small fish, crabs, octopus, and small crustaceans in kelp beds close to shore and near the seabed. New Zealand dolphins feed on species of small fish and squid in shallow coastal waters.

Orcas are the biggest members of the dolphin family; resident orcas in Northern British Columbia, Canada eat only fish – their favourite is salmon. Other orcas specialise in eating much bigger prey including seabirds and mammals such as sea lions, dolphins and whales. Orca diet depends on what food is available to them where they live and what techniques they have learnt from their elders to hunt their food.

Baleen whales extract their prey from seawater as it flows through or is forced through their baleen plates using their tongues and sometimes their throat muscles. They eat small shrimp-like krill, copepods and fish.

While toothed whales, such as dolphins, are thought to have a keen sense of taste, they lack an olfactory nerve and associated lobes and therefore it is believed that they are not able to smell their food. In baleen whales they are present but of limited use though there have been anecdotal reports that these whale might be capable of some airborne smell recognition.

How do whales and dolphin drink?

They get all the water they need directly from the food they eat. Their main prey (fish and squid) contains large amounts of water. Dolphins don’t lose water by sweating, like we do, and so they need less water than us in their diets.

Do dolphin eat jellyfish?

• yes

• no

dolphins like being alone

• true

• false

What sea creature eats kelp?

• starfish

• sea urchin

• dolphin

Dolphins are great swimmers. 

• True
• False

Đẹp đẽ

• Beautiful

• Polluted

• Dangerous

• Scared