\Zo"["e]*a\, n. [NL., fr. Gr. ? life.] (Zo["o]l.)
A peculiar larval stage of certain decapod Crustacea,
especially of crabs and certain Anomura. [Written also
{zo[ae]a}.]

Note: In this stage the anterior part of the body is
      relatively large, and usually bears three or four long
      spines. The years are conspicuous, and the antenn[ae]
      and jaws are long, fringed organs used in swimming. The
      thoracic legs are undeveloped or rudimentary, the
      abdomen long, slender, and often without appendages.
      The zo["e]a, after casting its shell, changes to a
      megalops.