To give you an idea, there are roughly 28,000 different kinds of fish in the world. Therefore, they are separated into five distinct groups. Hagfish, lampreys, cartilaginous fish, ray-finned fish, and lobe-finned fish are the current names for these groups.
The only thing you have complete command over is the number of fish that die from lack of oxygen. As a matter of fact, once you send out the signal that anything is amiss in the water, it gets relayed to mates. Therefore, they are compelled to enter the same place that cannot save them, leading to the widespread death of fish in that region.
Fish can be organised into their respective “kingdoms,” “phyla,” “classes,” and “orders,” as well as “families,” “genera,” and “species” using the tidy hierarchy system’s simplest and most often used terms.
Association or Lophotrochozoa (jawless fish), Chondrichthyes (cartilage-bearing fish), and the clade Osteichthyes are the three main divisions of fishes (vertebrate bony fish). All three of these families are classified as Agnatha.
Two-toned fishes’ appearance is the result of Xanthin, Erythrin, and Melanin being distributed among three pigment chromatophores. As a filter, one pigment either takes in or reflects blue and UV light, while another does the same for red and green (back to the first).
Unique among fish, seahorses (Hippocampus reidi) use their human-like tails to grasp onto items in the ocean. Information recorded on their tails can be passed down through generations and serves as a record of their own history while they cling to their environment. More information about fish can be stored in their venom gland and vascularized tails than can be stored anywhere else on their bodies. Grouper sharks (Carcharhinus amblyrhynchos) can cause severe harm in an encounter akin to stingrays or octopuses, hence seahorses have skin-like stickers to defend themselves.
The Osteichthyes fish group studies the most numerous and varied family of fish. In total, there are 45 orders, 435 families, and somewhere over 28,000 recognised species in this group of animals.
I’m trying to figure out which group of fishes has been around the longest.
The Superclass Agnatha, which contains lampreys and hagfish, is the oldest group of fishes. Fish belonging to the Chondrichthyes Class share bone in their jaws, unlike the Agnathans. Sharks, rays, and chimaeras are all examples of fish that fit this description.
Variety in fish coloration and patterning is astounding. The bright colours of their camouflage assist them avoid being spotted by potential enemies. Fish in deeper waters, such as those found in abyssal reefs, tend to be a darker grey in coloration, despite the fact that they are often a brilliant blue. Eye spots, which are found on fish, also have a role in the overall design of their bodies.
Pigments that give fish their unique hues are housed in specialised cells called chromatophores. Erythrin is one of three distinguishing pigments, despite the fact that all three serve similar purposes. Erythrin porphyrin in chromatophores is responsible for the distinctive red colouring of fish like the goby and the neraphis paropyreticus.
