A crustacean or rotifer is infected with a recombinant infectious virus that expresses a protein exogenous to the virus. The genome of the crustacean or rotifer itself remains unaltered. Crustacean, rotifer, insect, or viral promoters drive the transcription of a gene inserted into the recombinant virus genome, and the virus replicates in the crustacean or rotifer cell cytoplasm. The infected crustacean or rotifer can be provided directly to humans or non-human animals, or, following production and harvest of the crustaceans or rotifers, purified recombinant protein or polypeptide can be provided. Large quantities of biopharmaceuticals can be produced rapidly and inexpensively using this production system.