The most likely explanation for the variation is the offspring were produced from different combination of genes. A single pair of gold fish mentioned in the question means a male and a female gold fish. The two of them mated and contributed different genes to the fertilized fish eggs, this results in production of various body shape and colouration which is known as variation.
In a swamp a bird and a turtle feed on the same kind of fish. This will most likely result in Competition is an relations between organisms or species in which both need a resource that is in limited pool.
<h3>What is competition in an ecosystem?</h3>
Competition will happen between organisms in an ecosystem when their niches overlay , they both try to utilize the exact resource and the resource is in lack of supply.
Fuana contend for chow, water and area to live. flora contend for light, water, minerals and root area.
So,Competition is an relations between organisms or species in which both need a resource that is in limited pool.
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