Is a Dolphin a Fish?


  • Fish: Breathe through gills, which extract oxygen from water.
  • Dolphins: Breathe air through lungs, just like humans. They need to surface regularly to take in air.

Body temperature

  • Fish: Cold-blooded (ectothermic), meaning their body temperature changes with the environment.
  • Dolphins: Warm-blooded (endothermic), meaning they maintain a constant internal body temperature.


  • Fish: Lay eggs in water and the young hatch on their own.
  • Dolphins: Give birth to live young and nurse them with milk produced by mammary glands.

Other differences

  • Dolphins: Have hair (modified as whiskers), a trait not found in fish.
  • Dolphins: Possess a complex social structure and exhibit advanced intelligence compared to fish.
Is a Dolphin a Fish?
Is a Dolphin a Fish?

Therefore, while dolphins may share some physical similarities with fish due to their aquatic environment, they are distinct in their internal biological processes and belong to the class Mammalia. In this article, we’ll delve Is a Dolphin a Fish?

What do Dolphins Eat?

Dolphins are carnivorous marine mammals whose diet primarily consists of fish and squid. The specific types of fish and squid they consume can vary depending on the species of dolphin and the region they inhabit.

Some common prey species for dolphins include herring, mackerel, anchovies, and various small to medium-sized fish.Dolphins are known for their hunting techniques, including cooperative hunting, where they work together to corral and catch schools of fish.

They are also skilled at using echolocation to locate and target prey underwater.

Are Dolphins Mammals or Fish?

Dolphins are mammals, not fish. Like other mammals, dolphins are warm-blooded, have lungs for breathing air, give birth to live young, and nurse their offspring with milk produced by mammary glands.

Despite their aquatic lifestyle, dolphins share these characteristics with other mammals, distinguishing them from fish, which are cold-blooded, lay eggs, and extract oxygen from water through gills.

Is a dolphin a cartilaginous fish?

No, dolphins are not cartilaginous fish. They are not even fish at all! Here’s why:

  • Dolphins are mammals: Just like humans, whales, and bats, dolphins have warm blood, breathe air with lungs, give birth to live young and nurse their babies with milk.
  • Cartilaginous fish are a distinct group: They have skeletons made of cartilage, like sharks and rays. Dolphins, conversely, have frames made of bones, similar to other mammals.
  • Dolphins and fish have different evolutionary histories: Dolphins belong to Mammalia, while cartilaginous fish belong to Chondrichthyes. These two classes diverged from an everyday ancestor millions of years ago and have followed different evolutionary paths.

While dolphins and some fish share superficial similarities, like living in water and having fins, their internal structures and biology are very different. So, the answer to your question is a definitive no: dolphins are not cartilaginous fish. They are air-breathing, warm-blooded mammals with bony skeletons, making them much closer relatives to humans than any fish.

What Type of Animal Is a Dolphin?

What Type of Animal Is a Dolphin?
What Type of Animal Is a Dolphin?

A dolphin is a marine mammal. Dolphins belong to the order Cetacea, which also includes whales and porpoises. They are characterized by their streamlined bodies, dorsal fins, and a high level of intelligence.

Dolphins are known for their playful behavior, social structures, and communication skills. While they spend their lives in the water, dolphins are mammals and share common characteristics with other group members, such as breathing air, giving birth to live young, and nursing their offspring.

Do Dolphins Have Lungs?

Yes, dolphins have lungs and are obligate air breathers. Despite living in the water, dolphins need to come to the surface to breathe air.

They have blowholes on the top of their heads, which they use to breathe. When a dolphin surfaces, it exhales forcefully through its blowhole, expelling a spout of air, and then quickly inhales fresh air before submerging again.

This process is repeated periodically as they swim and dive. The lung adaptation allows dolphins to extract oxygen from the air, unlike fish, which extract oxygen from water through gills.

Is a Dolphin a Fish?

Are There Any Similarities Between Dolphins and Fish?

While dolphins and fish share some similarities in their aquatic lifestyles, they are fundamentally different types of animals. Here are a few similarities and differences:


  • Aquatic Habitat: Both dolphins and fish live in aquatic environments, primarily in oceans and seas.
  • Streamlined Bodies: Both dolphins and fish have streamlined bodies that help them move efficiently through the water.
  • Fins: Dolphins and fish have fins that aid navigation and balance.


  • Warm-Blooded vs. Cold-Blooded: Dolphins are warm-blooded mammals, meaning they can regulate their body temperature internally. On the other hand, fish are cold-blooded, and the temperature of the surrounding water influences their body temperature.
  • Breathing: Dolphins are air-breathing mammals with lungs surfacing to breathe through a blowhole. Fish extract oxygen from water through gills.
  • Reproduction: Dolphins give birth to live young, whereas most fish lay eggs.
  • Mammals vs. Fish: Dolphins belong to the group of marine mammals, while fish belong to the group of aquatic vertebrates.
  • Communication and Intelligence: Dolphins are known for their advanced communication skills and high level of intelligence, whereas fish generally do not exhibit complex social behaviors or communication.

Is There Any Fish Called “Dolphin”?

Yes, there is a fish called “dolphin,” commonly known as mahi-mahi or dolphinfish. The term needs to be clarified, as it doesn’t refer to marine mammals. Mahi-mahi (Coryphaena hippurus) is a vibrant, fast-swimming fish in tropical and subtropical waters.

Its distinctive colors and delicious flesh make it popular in both sport fishing and culinary contexts. The broader “dolphinfish” category includes various species like pompano dolphinfish (Coryphaena equiselis).

It’s crucial to differentiate between these fish and marine mammals like dolphins, warm-blooded mammals with lungs and a blowhole for breathing air.

11 Dolphin Fish Fun Facts

  • Not Actual Dolphins: Despite their name, dolphin fish, also known as mahi-mahi or dorado, are unrelated to actual dolphins. They belong to the Coryphaenidae family and are distinct species in warm ocean waters.
  • Vibrant Colors: One of the most striking features of dolphin fish is their vibrant colors. They can display a range of hues, including bright green, blue, and yellow, making them one of the most colorful fish in the ocean.
  • Rapid Growth: Dolphin fish are known for their rapid growth rate. They can reach lengths of up to 1 meter (3 feet) in their first year of life, and some individuals can grow even faster under optimal conditions.
  • Short Lifespan: Despite their impressive growth rate, dolphin fish have relatively short lifespans, typically lasting about four to five years. This short life cycle contributes to their high turnover in populations.
  • Fast Swimmers: These fish are renowned for their speed and agility. They can swim up to 50 miles per hour, making them one of the fastest fish in the ocean.
  • Migratory Behavior: Dolphin fish are highly migratory and often travel long distances. Following warm ocean currents, they are commonly found in tropical and subtropical waters worldwide.
  • Feeding Habits: Their diet consists of various prey, including small fish, squid, and crustaceans. They are opportunistic feeders, often hunting near floating debris where smaller fish gather for shelter.
  • Distinctive Head Bumps: Adult male dolphin fish often develop a bony, vertical forehead known as a “forehead.” This distinctive feature is absent in females and is believed to play a role in social interactions and hierarchy within the species.
  • Excellent Game Fish: Due to their size, speed, and acrobatic displays when hooked, dolphin fish are highly prized as game fish. Anglers seek them for their challenging fights and delicious flesh.
  • Rapid Reproduction: Dolphin fish are prolific breeders. Female fish can produce hundreds of thousands of eggs in a single spawning event, contributing to their ability to maintain populations despite their short lifespan.
  • Culinary Delight: Besides being a popular sportfish, mahi-mahi is a sought-after culinary delight. Its firm, white flesh has a mild flavor, making it a favorite in seafood restaurants worldwide. It’s commonly grilled, pan-seared, or used in ceviche.


In conclusion, dolphins are not fish but mammals with unique characteristics. Understanding and spreading this knowledge is essential for accurate conservation measures and a deeper appreciation of these incredible marine creatures.

Frequently asked question

  • Is a whale a fish?
    • No, a whale is not a fish. Whales are mammals belonging to the order Cetacea, while fish are cold-blooded vertebrates that belong to various classes, such as Osteichthyes and Chondrichthyes.
  • What type of animal is a dolphin?
    • Dolphins are marine mammals. They belong to the order Cetacea, which also includes whales and porpoises. Dolphins are known for their high intelligence, social behavior, and communication skills.
  • Is dolphin meat halal?
    • The permissibility of consuming dolphin meat in Islam is a matter of interpretation among Islamic scholars. Generally, most scholars consider marine mammals, including dolphins, permissible to eat, but opinions may vary. Individuals should consult with their local religious authorities for specific guidance.
  • Are mammals fish?
    • No, mammals are not fish. Mammals are animals characterized by mammary glands, giving birth to live young, and having a backbone. Conversely, fish are a diverse group of aquatic, cold-blooded vertebrates that typically have scales and fins. The classification of mammals and fish is based on distinct biological characteristics.

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