An ectoperitrophic association of microorganisms with the fairy shrimp Branchinella spinosa was investigated by standard
plate counts and scanning electron microscopy. Yeasts were found to form a monolayer structure attached to the inner surface
of the peritrophic matrix suggesting a strong symbiotic association. The bacterial population consisted mostly of members of
the genus Serratia, concentrated in the hindgut, and exhibiting chitinolytic activity. z 1998 Published by Elsevier Science
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