verb (used with object), banned, ban·ning. to prohibit, forbid, or bar; interdict: to ban nuclear weapons;The dictator banned all newspapers and books that criticized his regime.

The concept of species is famously difficult, especially for bacteria. Mayr’s ‘Biological Species Concept’ — that species are interbreeding groups separated from other such groups by reproductive barriers — would not apply to bacteria at all if, as once believed, they are always asexual, never recombining genetically.

A species is often defined as a group of individuals that actually or potentially interbreed in nature.

A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche.

Species is one of the most specific classification that scientists use to describe animals. Scientists use a system of binomial nomenclature to describe animals without the confusion of common names.

Fishes are a group of animals that are completely aquatic vertebrates that have gills, scales, swim bladders to float, most produce eggs, and are ectothermic.

Are fish classed as animals? According to science, fish are classed as animals. Fish belong to one of the six general animal groups which are: mammals, birds, reptiles, amphibians, fish and invertebrates. While the flesh of fish might not be considered as meat, fish are animals which have brains and can feel pain.

Unlike groupings such as birds or mammals, fish are not a single clade but a paraphyletic collection of taxa, including hagfishes, lampreys, sharks and rays, ray-finned fish, coelacanths, and lungfish. Indeed, lungfish and coelacanths are closer relatives of tetrapods (such as mammals, birds, amphibians, etc.)

Whales are warm blooded, which means they keep a high body temperature that does not change in the cold water. Fish are cold-blooded, so their body temperature changes depending on the temperature of their environment. Fish lay eggs, which must still grow into a baby fish. So whales are indeed mammals and not fish!