FATE OF THE 2ND MAXILLA DURING EMBRYOGENESIS IN SOME ANOMOPODA CRUSTACEA (BRANCHIOPODA)

The maxilla II, normally present in crustaceans, is absent in most adu lt anomopods although it was found to occur in embryos of six species of this group. The appendage is reduced in representatives of families that lack it in the adult. The disappearance of the second maxilla is accomplished in a different way in the Chydoridae and Bosminidae as c ompared with the Daphniidae. A biramous structure of this appendage wa s observed in some stages of development in the largest species of Ano mopoda. This feature of morphology is similar to the situation in othe r Branchiopoda. (C) 1996 The Linnean Society of London