How do crustacean larvae differ from adult crustaceans?

Crustacean larvae often differ from adults in their physical structure, particularly regarding their complexity and development. The most widespread and typical crustacean larva is the nauplius, which is characterized by a simple, unsegmented body, a single naupliar eye, and only three pairs of appendages—the antennules, antennae, and mandibles.1

In contrast, adult crustaceans typically possess a full complement of limbs, paired compound eyes, and a more complex, segmented body structure. During development, many crustaceans undergo a series of molts, gradually adding new segments and appendages until they reach their adult form. Some species transition through various specialized larval stages, such as the protozoea, zoea, or megalops, each adapted for different methods of locomotion or environmental needs.12

While many crustaceans utilize these distinct larval stages for dispersal or to exploit different ecological niches, some species bypass free-living larval stages entirely; in these cases, the young emerge from the eggs already resembling miniature versions of the adults.1