Isozyme electrophoresis was used to identify the larvae of 7 species of penaeid prawn: Penaeus merguiensis
P. penicillatus
P. orientalis
P. monodon
P. japonicus
Metapenaeus ensis and M. affinis taken from the artificial nursery plants. The 7 species were examined for esterase in two development stages ( mysis and megalopa substage). A key to enzyme spectra of esterase
in the 7 species of penaeid prawn at larval stage
was suggested. The major factors affecting the electrophoretic identification system when being applied were discussed.