Only animals which are viviparous (give birth to live offspring) have gestation periods.
Not always, but in general, the larger the animal, the longer the gestation period.
cod doesnt have a gestation period, because it is an egg layer. Cod, being a type of fish is an external reproductive organism, therefore there isnt a gestation period for any kind of fish
it is different for every animal
oppossum
The gestation period for each animal is different. For example Elephants have a gestation period of 22 months where as polar bears one of only 8 months.
The shortest known gestation period is the Virginian opossum, which is 12 days. The longest period belongs to the Indian elephant, which has a gestation period of 22 months.
Sheep and goats.
Gestation is the pregnancy of an animal. In heelers it is usually 56-72 days.
Two marsupials share the shortest gestation period. The Virginian opossum and the yapok (an unusual, rare water opossum) have a gestation period period of 12-13 days. Several sources cite the Eastern quoll of Australia as also having a gestation period of 12-13 days, but this is incorrect. The Eastern quoll's gestation period is 21 days. The longest known gestation period of any animal is that of the African elephant. Its gestation period averages 660 days but can extend to 760 days.
Gestation is when an embryo is inside the womb of female animal. The gestation period is the female's pregnancy, from conception to birth.
The gestation period of a mouse, a small animal known for its rapid reproductive cycle, is typically around 19 to 21 days.
The gestation (not gestination) period of an animal is the time from conception to birth. In humans it's 9 months.