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 | Sharks | Dolphins |
| Group | Sharks are cartilaginous fish | Dolphins are mammals |
| Species distribution | Sharks have nearly 440 species that are distributed all over the world | There are 40 species of dolphins that are reported till date |
| Skin | Sharks possess rough and hard skin | Dolphins have shiny and smooth outer skin layer |
| Size | They ranging in size from 6 inches to 40 feet in length | They ranging in size from 6 feet to 31 feet in length |
| Speed | They can move with the speed of 50 kilometer per hour in the ocean water | They can move with high speed throughout the ocean up to 29 kilometers per hour |
| Mouth | The location of their mouth is just under their skull | Their mouth is located in front of their skull |
| Teeth | Sharks possess normally 5 to 300 teeth with several rows of teeth in jaws | They have variable number of teeth ranging from 14 to 240 with only single row of teeth in jaws |
| Teeth shape | Sharks bears triangular shaped teeth for capturing prey | Usually dolphins have cone shaped teeth to capture prey |
| Habitat | Sharks are found in the oceans throughout their life but some exceptional species may live in freshwater | As dolphins are categorized as mammals, so they mostly spent their time near the ocean surface |
| Thermoregulation mechanism | Sharks are cold blooded species so they do not tend to regulate their body temperature with the surrounding environment | Dolphins are warm blooded species so they have the ability to regulate their body temperature with the environmental changes |
| Respiratory organs | They possess lungs which helps them in respiration | They have gills which are responsible for respiratory mechanism |
| Reproduction | Sharks are ovoviviparous means they lay eggs as well as give birth to young pups | Dolphins exhibit viviparous mode of reproduction by giving birth to their young pups |
| Skeleton | The skeleton of sharks is completely impregnated with cartilage | The skeleton of dolphin is made up of bones |
| Weight | The weight of sharks ranges from 680 to 2268kg | The weight of dolphins ranges from 40kg to 10 tonnes |
| Behavior | They mostly prefer to live lonely but may gather sometime | They are highly social species and have friendly relation with other water species |
| Digestive system | The intestines of sharks are smaller in size as compared to dolphins | The dolphins have longer intestines as compared to sharks |
| Diet | Sharks feed on any animal present in its vicinity | Dolphins feed on squids, small fishes an jellyfishes |
| Intelligence | Sharks are quite less intelligent than dolphins because of the larger size of their brain | Dolphins are reported as more intelligent than sharks because they are capable of imitating, have self-awareness, understandable and liveliness |
| Tail fins | They possess vertical tail fins | They possess horizontal tail flukes |
| Life span | The lifespan of sharks is about 20 to 30 years | The 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.