Shark vs Dolphin | How to tell the difference - (2023)

Imagine; You're surfing the beach with your friends and you spot a fin sticking out of the water and you don't know if it's a shark or a dolphin. In such situations, it is important to know whether the fin sticking out of the water is from a shark or a dolphin. However, there can be many similarities between the two, which is why we're going to take a look at all the tiny details of Shark vs Dolphin Fin. The two are similar and different in several ways. Let's examine them in this article.

Sharks and dolphins can be misunderstood by people who don't understand the clear differences between the two. Sharks are deadlier creatures than dolphins. Dolphins, on the other hand, are friendly but exceptionally intelligent creatures. Seeing one of them on a beach would require different reactions, so it's important to know what the difference is between a shark fin and a dolphin fin.

They may appear similar from the water's surface, but they are quite different when you look closely. Let's learn more about shark and dolphin fins.

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What do sharks and dolphins have in common?

These species also share some similarities as both are greyish in colour, aquatic animals characterized as vertebrates because both possess a backbone. Both typically tend to live and swim in the ocean, and their diet includes invertebrates and small fish. Both have dorsal fins positioned on the back and pectoral fins positioned on the sides.

Are they different from each other?

Although sharks and dolphins share many physical characteristics that are similar to both of them, it sometimes makes it difficult for people to decide whether it could be a shark or a dolphin? But knowing a few details about their distinctive traits will help you distinguish between them. Let's find out what characters distinguish them from each other.

What are the differences between sharks and dolphins?

First, let's talk about the shape of a shark fin and a dolphin fin. As for the dolphin's fin, it's bent backwards a bit. This would mean that there is a distinct backward curve seen on a dolphin's fin. Most dolphins have a fin with a sharply curved tip that distinguishes it from a shark's fin. The exact shape of a dolphin's fin may differ with type change, but the backward curve is always there.

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Sharks also have their fins angled backwards. However, the difference lies in the trailing edge of a shark fin. As we mentioned earlier, dolphins have a sharply curved rear end while sharks have a straight rear end, although the fin is angled in a flexed position. So if you're looking at a curved fin with a straight back end, it's most likely a shark and you should get to safety before it reaches you.

Second, let's see how you can distinguish between a shark fin and a dolphin fin based on their movements. It's important to understand that both sharks and dolphins have a lot of control over their fins. The only thing that counts is how they cross the water. If this changes, it can have different effects on their visible fin. If you observe a dolphin you will see that it has a broad horizontal tail that bobs up and down as it moves in the water.

However, how sharks move is different. If you watch a shark swimming around you will see that it has a high vertical tail. Sharks swim by moving these vertical tails side by side. Now the effects of movement type on a fish's fin can be observed from outside the water to determine if it is a shark or a dolphin. If the fin seems to move up and down, it's most likely a dolphin. On the other hand, a fish is most likely to be a shark when its fin is moving back and forth.

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By observing the fin, you can also identify it; it's progressing by the way. Sharks usually keep moving forward without bobbing around. So if you see a fin heading straight for something, there's a good chance it's a shark. On the other hand, if you see a fin swimming around in the water and playing with the waves, it's more likely a dolphin.

The number of fins you see in the water at once can also tell you if a shark is coming your way or a dolphin. Sharks don't usually swim around in groups. Even when there are multiple sharks in one area, they avoid swimming together, so when you look at a shark, you only see one fin.

In dolphins, however, the situation is different. This is because dolphins typically live in small groups called pods, unlike sharks, which are solitary. So that establishes that when you see a dolphin, you're more likely to see a bunch of them together.

(Video) Sharks for Kids

groupSharks are cartilaginous fishDolphins are mammals
species distributionSharks have nearly 440 species distributed around the worldThere are 40 species of dolphins that have been reported to date
HighSharks have rough and tough skinDolphins have a shiny and smooth outer layer of skin
SizeThey range in size from 6 inches to 40 feet in lengthThey range in size from 6 feet to 31 feet in length
speedThey can move in sea water at a speed of 50 kilometers per hourThey can move through the ocean at a high speed of up to 29 kilometers per hour
CanThe location of her mouth is just below her skullHer mouth is in front of her skull
TeethSharks typically have 5 to 300 teeth with multiple rows of teeth in the jawThey have a variable number of teeth ranging from 14 to 240 with only one row of teeth in the jaw
ZahnformSharks have triangular teeth for catching preyDolphins usually have cone-shaped teeth to catch prey
habitatSharks are found in the oceans all their lives, but some extraordinary species can live in fresh waterBecause dolphins are mammals, they spend most of their time near the sea surface
ThermoregulationsmechanismusSharks are cold-blooded species, so they don't tend to regulate their body temperature with the environmentDolphins are warm-blooded species, so they have the ability to adapt their body temperature to environmental changes
respiratory organsThey have lungs that help them breatheThey have gills that are responsible for the respiratory mechanism
ReproductionSharks are ovoviviparous, meaning they lay eggs and give birth to young pupsDolphins demonstrate a viviparous mode of reproduction by giving birth to their young pups
skeletonShark skeletons are completely impregnated with cartilageThe dolphin skeleton is made of bones
WeightThe weight of sharks ranges from 680 to 2268 kgThe weight of the dolphins ranges from 40 kg to 10 tons
BehaveThey mostly prefer to live solitary, but may gather at some pointThey are very social species and have a friendly relationship with other aquatic species
digestive systemShark intestines are smaller compared to dolphinsThe dolphins have longer intestines compared to sharks
DietSharks will feed on any animal that comes near themDolphins feed on squid, small fish and jellyfish
intelligenceSharks are significantly less intelligent than dolphins due to the size of their brainsDolphins are considered more intelligent than sharks because they can mimic, are confident, understandable, and lively
Tail finsThey have vertical caudal finsThey have horizontal caudal fins
lifespanThe lifespan of sharks is around 20 to 30 yearsThe lifespan of dolphins is usually 20 years

Do sharks and dolphins have a common ancestor?

There are many internal or external characteristics that distinguish them from one another. Sharks are the cartilaginous fish species while dolphins are categorized as aquatic mammals. Both species belong to the same evolutionary period as they prefer to thrive in the sea and enjoy swimming at high speeds. Most interestingly, they share the same ancestral history – the ancestors of sharks and dolphins have been reported to have appeared on Earth more than 290 million years ago.


There are many differences between a shark fin and a dolphin fin. However, most of them cannot be spotted until they are fairly close to you. So, to observe if the fin coming your way is a shark or a dolphin, you should consider the above things to educate yourself about the species beforehand.


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