Can you tell the difference between a shark and a dolphin? Consider the following tips when identifying these two creatures that live in the same ecosystem.
The shark is a cartilaginous fish from a diverse group of animal with about 440 species. It can live in deep and shallow waters. It can be as small as 15 cm long such as the deep sea shark or as long as 12 m like the whale shark. The shark is the top hunter in the marine ecosystem. The shape of its tail varies within species. This creature does not have a swim bladder but its large oil-filled liver and its light cartilaginous skeleton help to keep it afloat. It breathes through gills and it can live for 20- 30 years.
The dolphin has mammalian features. There are about 40 species of dolphins all over the world. The dolphin is mostly found in shallow waters. Its size can vary from one to ten metres in length and from 40 kg to 10 tonnes in weight. Its streamlined body makes it a fast swimmer. It breathes through its lungs. It feeds on fish and squids. Dolphins are intelligent and they hunt in herds. The lifespan of a dolphin is about 20 years.
Test Your Science
1. Give two differences between the shark and the dolphin.
Look up the similarity between the dolphin and the shark in the Young Scientists Issue 109 Level 1.
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