There are approximately 32,000 species of fish in the world, living in both fresh and saltwater bodies. Looking at classification, fish are classified as members of kingdom Animalia, falling under phylum Chordata and vertebrate subphylum. Due to this reason, therefore, most fish species found in the world are cold-blooded, except one species known as the Opah, which is a warm-blooded fish. However, as a member of Phylum Chordata, fish share some definite features with other vertebrates, for instance, gill slits, a tail, notochord, a dorsal hollow nerve cord, and a skeletal supporting rod.
Apart from knowing the kingdom, phylum, and sub-phylum classification of fish, there are several other things you need to know about fish. Fishes are of interest to humans for several reasons and most importantly being their relationship and dependence on the environment.
1. Fish Have Personalities
Many people have been forced to the belief that all fish species lack personalities as compared to some other living organisms. The fact is that fish do think just like other animals with minds and lives of their own. Just like human beings, some fish species are more aggressive; some are shy, and curious while others are devious. These, therefore, are but a few personalities the fish have.
2. Fish Go To Greater Lengths To Care For Their Young
It is also important to note that fish are the most sensitive animals on earth when it comes to matters about caring for their young ones. Just like a lion, parent fish defend their eggs from predators. Hence, some fish actually leave the water to lay their eggs in a hidden and safe place. In some extreme cases, some fish species wear their eggs like hats to keep them close and safe.
3. Fish Make Noises
For decades, scientists assumed that fish are deaf since they lack external ears. Of importance to note is that, just like any other living creature, fish can hear and make noise. More surprising is the fact that some fish species can hear noises and make sounds louder than we do as human beings. Therefore, some of these common noises made by fish include, croaking, whistling, clicking, humming, and growling.
4. Fish Can Feel Pleasure And Pain
Another essential fact about fish that you need to know is the fact the fish can also feel pleasure and pain. Research has proved that, apart from being annoying, scaly robots, fish can feel pain as intensely as other animals. On the other hand, when a stressed fish when stroked or touched, their cortisol levels lower due to pleasure.
5. Fish Join Forces
It is interesting also to know that, fish of different species team up together to combine forces just like Avengers do. Some of the fish species commonly known to joining forces are Coral groupers and moray eels who usually come together to hunt. These two species have been continually working hand in hand, with the groupers being great hunters while the eels are unstoppable in cracks and crevices, thus making a strong team which a few predators can escape.
The study of fish, which is referred to as the science of ichthyology is of immense importance. Therefore, these are but a few facts about fish that I thought you should know and more importantly help you understand some hidden truths about fish.