THOSE TWO QUESTIONS PLS^

1: if the species health is low it will affect everyone in the habitat as well as how the habitat functions, because the species will not be behaving as normal and might not care for the habitat.

2: all the fish  in the stream can adapt a genetic protection against diseases due to the different types of adaptions and DNA structures, the fish mating will produce stronger fishes who can live through different types of disease

Explanation:

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.