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Without light guppies (and most other species of fish) can not see one another so it would be extremely difficult for them to locate one another let alone breed successfully. Therefor I would say that the effect of light would be to 'enable' reproduction of guppies.
the fish have to have sex
The highest rate of reproduction for a population is called a biotic.
He called the differential rate of reproduction 'Survival of the Fittest.'
A higher birth rate is a rate of reproduction greater than the current norm, or average, or a rate of reproduction greater than a norm or average at a given time.
Guppies typically grow about 1-2 inches in their first few months of life. Factors that can influence their growth rate include water temperature, food availability, genetics, and overall health.
37
woodchuck reproduction rate
Biotic Potential.
456
Fries (the term for baby guppies), are eaten by older guppies, but guppies are eaten by fish like tuna.
Only guppies breed with guppies naturally.