What is the difference between fish eggs and bird eggs?

Fish eggs, commonly known as roe, are typically small, jelly-like, and often found in clusters, depending on the species. They are usually fertilized externally in water, where the developing embryos rely on the surrounding environment for oxygen and nutrients. In contrast, bird eggs have a hard shell that provides protection and a controlled environment for the developing embryo, which is fertilized internally. Bird eggs contain yolk and albumen, providing nourishment during development, and are usually laid in nests.