Here's why:
* Limited Abilities: Fish larvae are often very small and fragile. They lack the developed features of adult fish, such as fully functional gills, fins, and digestive systems. They are also typically less adept at swimming and hunting for food.
* Metamorphosis: Fish larvae undergo a dramatic transformation as they grow. Their bodies change in shape, size, and structure, and they develop new abilities. This metamorphosis can take weeks or even months, depending on the species.
* Environmental Dependence: Larvae are highly dependent on their environment for survival. They need access to suitable food sources, adequate water quality, and protection from predators.
Examples:
* Salmon: Salmon hatchlings (called alevins) are small and have a yolk sac attached to their bellies. They live in gravel nests and rely on the yolk sac for nourishment until they develop the ability to swim and feed.
* Clownfish: Clownfish larvae are transparent and have a long, thin body. They drift with the currents and rely on their yolk sac for sustenance. They eventually develop their distinctive coloration and body shape.
Conclusion:
Fish are not fully developed when hatched. They undergo a complex developmental process called metamorphosis, which transforms them from larvae to adults. This process involves significant changes in their bodies, abilities, and behaviors.