neanic
From ZooTerms (Dictionary of Invertebrate Zoology)
immature; a stage of development between the brephic and mature.
neanic (adjective; Greek neanikos, fresh): 1. Being youthful or
2. (Arthropoda: Insecta) The pupal stage.
3. (Brachiopoda) A youthful stage when generic characters are beginning to become apparent.
4. (Bryozoa) Zooids laid down in the phase of astogenic change.