How is fish classification done? How do scientists decide which fish are included in which subgroups?
Scientists classify fishes in order to have a working method of describing various species of fish and to be able to appropriately follow how one generation of fish evolves from another. We need to have such classifications in order to know just how diverse the world is when it comes to living creatures. It also helps when it comes to knowing which type of fish we're eating on our dining room tables, and keeps us in context when it comes to knowing the backgrounds of different types of fish.
In recent decades, scientists have taken the classification of fish a step further. They wanted an even more organized way of describing different fish. So, they created various levels of classification such as a class, order, family, or genus of animal. Each species in related categories share the same ancestors but have evolved differently.
Most fish fall under three main classes: jawless fish (i.e. hagfish and lampreys), cartilaginous fish (i.e. sharks, rays, and skates), and bony fish (i.e. lungfish, eels, carp, lizardfish, silversides, salmon, and etc.).
Achieving proper identification for fish is a priority for many scientists. A series of rules called The International Code of Zoological Nomenclature looks at many of the issues associated with naming animals. It establishes rules for naming fish, and what to do if one fish is ever learned to have been given two different names. The goal of these rules is to have one common worldwide method of naming these creatures.
New animals are discovered each year, mainly because the world's animal kingdom is constantly under development and not all regions of every land, ocean and stream area has yet been explored at all depths.