Question

What are introduced species? How are they a threat to biodiversity?

Answer 1

Species is a rank in taxonomy given to a large group of organisms that can reproduce their young ones similar to them. Species of animals are adapted to the environment they live in. If the animals of a species do not adapt to the environment or other species around them, they are not able to survive. Thus the ability to adapt to the surrounding is an important factor for existence or extinction of living organisms.

Complete answer:
-An introduced species is the non-native species. When a species is intentionally or accidentally introduced to an environment that is not native to it, mostly due to human activities, it is called an introduced species. For example, water transport using large ships has been going on for many years. Along with the grains or goods of import or export, the rat species were also unintentionally transported from one region to another. Thus those species of rats could be called the introduced species.
Other examples of introduced species are that of agricultural animals like cows, buffaloes, or pets like rabbits, cats, dogs, hens, etc.
-When a non-native species is introduced along with the native species, they tend to reproduce hybrids. This may be advantageous as well as can show negative effects. The hybrids formed may or may not be able to withstand the changing environment thus leading to reduced survival. Also, competition can be introduced between the native and non-native species for access to food, habitat, or any other factor.
-This may lead to reduced survival rates of the native species. There are chances that the predator dependent upon the native species are not able to get their food due to a low number of prey species. In short, the balance of the food chain may be disrupted causing a threat to biodiversity. Thus the introduced species may prove to be advantageous in case of plant species (Eg. corn, Wheat Triticum ) or may even be a threat to biodiversity (Eg. Atlantic Salmon).

Note: The reasons for the intentional introduction of species may be:
-Human enjoyment
-Agricultural needs (to develop crop varieties)
-Animal husbandry and cattle for increased milk, meat, or fur production.
-Other names for introduced species are alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species.