Variations in biochemical composition of juvenile Ruditapes philippinarum infected by a Vibrio sp.

Abstract

The biochemical composition of young Rudltapes phlllppinaruln was exanlined in 2 groups of clams, healthy clams and those expenmentally Infected with the pathogenic V ~b n o P1 bactenum to document utilization of biochemical reserves in ~n d ~v i d u a l s affected by 'brown ring d ~s e a s e ' After 1 mo of starvation, refeedlng half of the expenmental clams induced recovery as determined by the absence of v ~s u a l slgns of disease D ~s e a s e was associated with decreased dry weights In both fed and starved individuals (from 41 down to 30-35 mg clam ' ) Glycogen was found to be the main biochemical reselve used by diseased ~ndlviduals A significant decrease In glycogen (from 45 down to 20-25 my g ' dry wt) was observed in infected clams Lipid and proteln amounts were related to nutritional conditions In refed ~ndividuals, carbohydrate reserves were low In s p ~t c of some iecovery These results could Indicate an ~rieversible change of the digestive gland manifested by the inabil~ty to store reserves and distnbute them to other tissues In the field, mass mortal~ties obseived in infected popul a t ~o n s could result from the degeneration of metabolic actlvity