604 Marine Microbiology 



large chitinoclastic microflora was found associated with a cope- 

 pod and an amphipod, with fewer or none found in others, even 

 of morphologically similar (same species?) plankters. 



It should be noted, in comparing the three zooplankton 

 samplings, that the plankters in Cruise 4 were taken in a mid- 

 water trawl, and were generally much larger specimens than the 

 plankters of Cruise 3 and 5, which were taken in standard net 

 tows. 



Table 3 shows the semiquantitative estimation of the micro- 

 flora of tire zooplankters of Cruise 5. The data in Table 2 are the 

 records of the numbers of colonies on plates, while these data 

 have been recalculated, taking dilution into account, in Table 3 

 to indicate the approximate levels of the bacterial populations 

 and the chitinoclastic microflora associated with the individual 

 zooplankters. The counts range from 10^ to 10^ per organism, and 

 with a method of sampling that would provide more homogeneity, 

 would probably be considerable greater. 



Eight fish were taken in the midwater trawl of Cruise 4, and 

 the viscera aseptically removed and treated as described above. 

 The chitin agar plates made on the cruise met misfortune, but the 

 viscera were left to stand in the sea water blanks for 30 days at 

 room temperature, then sampled and plated on chitin agar. Four 

 specimens of the myctophid Lampanyctus sp. contained many 

 chitinoclastic bacteria, while the viscera from three specimens of 

 saury, Cololabis saira, showed few chitinoclasts. On Cruise 5 the 

 viscera from one myctophid was sampled and showed the pres- 

 ence of chitinoclasts, while one saury showed none. 



DISCUSSION 



The distribution of heterotrophic bacteria in pelagic waters 

 has been described by many investigators, among them Gazert 

 (9), Reuszer (21), Russell (22), Otto and Neumann (19), Graf 

 (10), Bertel (4, 5), Schmidt-Nielson (23), Foyn and Gran (8), 

 Drew (7), ZoBell (28), Jannasch and Jones (14) and Kriss et al. 

 (17). Most of the Russian endeavors in this field were recently 

 summarized by Sieburth (24). 



From the literature and from the data presented here, pela- 



