Challenges
Captive breeding techniques are usually difficult to implement for highly mobile species like some migratory birds (e.g. cranes) and fishes (e.g. Hilsa). Species like large cetaceans (whales, dolphins, etc.) may also have some difficulties as it would be hard to meet their biological requirements in captivity, especially the vast amount of space required to keep large populations.
Read more about this topic: Captive Breeding
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