Scientific community is aware of the present scenario of pollution level in aquatic ecosystems and changing climate.

Is the rate of description of new species of fishes correct/ justified? Where the minor changes in the environmental conditions and exposure to toxic conditions or pollution in developmental stages is bound to bring some changes, most probably negative and may bring changes in phenotypic characters. These changes may be seen in single specimen or a group. The long exposure may also bring in changes at genetic levels. These changes may be very small or measurable. Can this not be considered as deformity/ abnormality? Many times new species are described based on a single specimen and with smallest / minor change in character. Many times against the rule of nature breeding/ feritization may occur in two species; probability is more in closely related ones.

I feel a new species should not be described based on single specimen and with little change in character with closely related species, like very small change in number of gill raker or number of rays.