Table 1.

Comparative colonization characteristics ofV. fischeri strains

V. fischeri strainHost speciesaInoculum concn (CFU/ml) resulting in a 50% infection ratebTotal CFU per light organ (104) after 48 hc
ES114E. scolopes75042
ES12E. scolopes40025
ES213E. scolopesND46
ES401E. scolopesND90
EM17E. morsei20042
EM18E. morsei10031
EM24E. morsei7017
MJ11M. japonica10,0004.5
CG101C. gloriamaris2,0000.62
  • a Strains were isolated from light organ homogenates of the indicated host species (5). Each isolate was obtained from a different animal.

  • b For each strain, groups of 10 newly hatchedE. scolopes squids were exposed for 3 h to seawater containing between 102 and 105 V. fischeri cells per ml. The approximate concentrations of cells that were required to infect 50% of the juvenile animals are given. ND, not determined.

  • c Symbiont cell numbers (CFU) were estimated by homogenizing the light organ and plating serial dilutions on a nutrient medium (69).