Fish are aquatic vertebrates. Usually they have fins and a long body covered with scales. They are cold-blooded.
The word fish commonly relates to ray-finned fishes, sharks, lampreys and coelacanths. Them recognize can be a hard task because fish are surprisingly different. Around 33,600 species live through the whole world.
Easy Ways to Identify Fish
Body shape is a good spot for start identification of fish. Here the simplest ways separate them according to families. For instance, eel-alike form calls eel-like.
Such body helps biologists focus on certain species. Round shape also is common type. Such fishes have long a bit rounded body with eyes on either side.
Fin shape and position gives extra indications. They even show do the fish swims slowly or quickly.
Other traits help get closer to the identification. Some fishes have even spaced black spots according to rows under a black lateral line. At others show little rough thicket of teeth on the tongue.
Spotted bass have the first and second dorsal fins combined. Some like a crossing between crappie and red ear. Then observe the scale pattern and body are helpful.
For instance burbot have eel-alike body where anal and dorsal fins involve half the length of the body and seem to coincide with the tail.
Many methods help to find the identity. Google image reverse search works well for any fish. Mobile apps identify them wherever you are.
Some allows to search according to color pattern region habitate or physical form. Field guide over and over forms a base for image identification. That means to start with the family later genus and species.
Diving in tropics many from the 4,000 species belong to only some families. Knowing those attributes identification becomes much more simple.