Comparison of nt and deduced aa sequences of Perkinsus cob and cox1 with counterparts in other alveolates revealed that correct translation of Perkinsus mt genes required the Mold/Protozoan/ Coelenterate mt codon table (TGA codes for tryptophan) in general. To be fully translatable without internal stop codons, however, frameshifts had to be introduced at every AGG and CCC codon, the equivalent of using AGGY to code for glycine (six sites in cob and 7-8 sites in cox1) and CCCCU for proline (twice in cox1) (Figures 4, 5 ). An analogous result was reported by Masuda et al. [20] for the P. marinus cox1. Multiple cDNAs and genomic sequences substantiated these unusual reading frames, as well as the direct sequencing of PCR products. An interesting difference was found between the two Perkinsus species: at one site in cox1, glycine was encoded by an AGGU codon in P. marinus, but by a standard GGU codon in P. chesapeaki ( Figure 5 ). With the introduction of these invoked anomalous quadruplet and quintuplet codons, the deduced aa sequences of the two Perkinsus COX1 were 98% identical to each other, 46-50% similar to the homologs in apicomplexans, 42-49% to dinoflagellates, 29-31% to ciliates, and 38-42% to other organisms ( Figure 6 ). For cob (Figure 4) , besides the quadruplet codon AGGY, glycine was also encoded by the quintuplet codons UAGGC (for P. marinus) and UCGGU (for P. chesapeaki). After these adjustments, the deduced COB aa sequences of the two Perkinsus spp. shared 97% similarity to each other, 34-36% to apicomplexans, 22-44% to dinoflagellates, 15-17% to ciliates, 27-33% to other organisms (Figure 6 ).