Sharks vs Dolphins – What’s the Difference?

Sharks and dolphins are the beautiful creatures of the aquatic ecosystems. If you have a sight from the surface of water, it is very difficult for you to differentiate between sharks and dolphins because they look quite similar due to their color and shape but if you look closely, you can find a number of differences among them. To get a full knowledge of these ocean species, let’s start by exploring the similarities and major differences between them.

Do Sharks and dolphins share common ancestors?

There are many features either internal or external, which differentiate them from each other. Sharks are the type of cartilaginous fishes while dolphins are categorized as mammals that live in water. Both species belong to the same evolutionary period, as they prefer to thrive in the ocean and enjoy swimming at a high speed. Most interestingly, they share the same ancestral history – It was reported that the ancestors of sharks and dolphins appeared more than 290 million years ago on the Earth.

What similarities do sharks and dolphins have?

These species also share some similarities as both are of grayish color, aquatic animals which are characterized as vertebrates because both possess backbone. Both usually tend to live and swim in the ocean and their dietary food includes invertebrates and small fishes. Both possess dorsal fins positioned at the back as well as pectoral fins positioned on the sides.

Do they differ from each other?

Although  sharks and dolphins have many physical characteristics that are similar to both of them, sometimes it makes it difficult for people to choose whether it could be a shark or a dolphin? But to know a bit of detail about their distinctive features will help you to differentiate between them. let’ find out what characters make them different from each other.

Features SharksDolphins
Group Sharks are cartilaginous fishDolphins are mammals
Species distributionSharks have nearly 440 species that are distributed all over the worldThere are 40 species of dolphins that are reported till date
SkinSharks possess rough and hard skinDolphins have shiny and smooth outer skin layer
SizeThey ranging in size from 6 inches to 40 feet in lengthThey ranging in size from 6 feet to 31 feet in length
 SpeedThey can move with the speed of 50 kilometer per hour in the ocean waterThey can move with high speed throughout the ocean up to 29 kilometers per hour
MouthThe location of their mouth is just under their skullTheir mouth is located in front of their skull
 TeethSharks possess normally 5 to 300 teeth with several rows of teeth in jawsThey have variable number of teeth ranging from 14 to 240 with only single row of teeth in jaws
Teeth shapeSharks bears triangular shaped teeth for capturing preyUsually dolphins have cone shaped teeth to capture prey
 HabitatSharks are found in the oceans throughout their life but some exceptional species may live in freshwaterAs dolphins are categorized as mammals, so they mostly spent their time near the ocean surface
  Thermoregulation mechanismSharks are cold blooded species so they do not tend to regulate their body temperature with the surrounding environmentDolphins are warm blooded species so they have the ability to regulate their body temperature with the environmental changes
 Respiratory organsThey possess lungs which helps them in respirationThey have gills which are responsible for respiratory mechanism
 ReproductionSharks are ovoviviparous means they lay eggs as well as give birth to young pupsDolphins exhibit viviparous mode of reproduction by giving birth to their young pups
SkeletonThe skeleton of sharks is completely impregnated with cartilageThe skeleton of dolphin is made up of bones
WeightThe weight of sharks ranges from 680 to 2268kgThe weight of dolphins ranges from 40kg to 10 tonnes
 BehaviorThey mostly prefer to live lonely but may gather sometimeThey are highly social species and have friendly relation with other water species
Digestive systemThe intestines of sharks are smaller in size as compared to dolphinsThe dolphins have longer intestines as compared to sharks
DietSharks feed on any animal present in its vicinityDolphins feed on squids, small fishes an jellyfishes
  IntelligenceSharks are quite less intelligent than dolphins because of the larger size of their brainDolphins are reported as more intelligent than sharks because they are capable of imitating, have self-awareness, understandable and liveliness
Tail finsThey possess vertical tail finsThey possess horizontal tail flukes
Life spanThe lifespan of sharks is about 20 to 30 yearsThe lifespan of dolphins is usually 20 years

Final Thoughts

Sharks and dolphins share many common features and share the same evolutionary history but they differ from each other in many ways as well. The information provided in the above article might be enough to differentiate between sharks and dolphins. So whenever you see a giant gray coloured species in the water, don’t panic, use your knowledge to recognize whether it is a shark or a dolphin.

About the author