Let's look at the classification of marine fish. Fish in the ocean are mainly categorized into two main groups: scleractinian fish and cartilaginous fish. The hard-boned fish include our common tuna, salmon, flounder and so on, which have a hard internal skeletal structure. Cartilaginous fish, on the other hand, include more specialized species such as sharks and manta rays, which have no real hard bones but are composed of cartilage.
Fish in the oceans can be further categorized into various families, genera, and species based on their habits and diet. Families categorize a group of similar species, while genera are further refined to groups of species that are more similar. Species, on the other hand, categorize groups of individuals of the same species that maintain a stable ability to reproduce with each other. This categorization leads down to the numerous species of marine fish.
Next, let's look at the classification of freshwater fishes. Freshwater fishes mainly live in freshwater environments such as rivers and lakes, and they are adapted to different habitats and climatic conditions. Common freshwater fishes include *fish, carp, tilapia, etc., which have obvious differences in their food habits and morphology. Similarly, freshwater fishes can be categorized by family, genus and species.
In addition to being categorized according to habitat and food habits, fish can also be classified according to body size and characteristics. Some fish are large, such as the giant whale shark, while others are smaller, such as ornamental fish. Some special forms of fish also attract attention, such as deep-sea camera fish with light-emitting organs and butterfly fish.
The world's fish are too diverse to list. They are found in different waters and are meticulously categorized according to their habits, food habits, body size and other characteristics. From bony marine fish to cartilaginous marine fish, to freshwater fish, each category has its own characteristics and unique features. With the continuous progress of science and technology, we believe that more new fish species will be discovered in the future.