Bacterial Viruses in the Sea 



355 



details of the phages isolated. In all, six liters of sea water were 

 examined by the direct method and almost 40 liters by the in- 

 direct method. 



TABLE 3 

 Details of the Marine Phages Isolated 



THE CHARACTERISTICS OF MARINE PHAGES 



Although phages active against marine bacteria have now 

 been shown to be present in sea water, virtually nothing would 

 appear to be known of the ecology of such phages; their dis- 

 tribution in the seas, in space or in time, their inteiTelationship 

 witli bacterial populations; nor their characteristics. A few fig- 

 ures for their concentration in one area over a limited period of 

 time have been given, together with a few details of certain 

 characteristics of one marine phage (17). These few details do, 

 however, raise the interesting possibility that some marine phages 

 may have certain characteristics quite different from terrestrial 

 bacteriophages and that these characteristics may be a reflection 

 of their environment. Two characteristics which tend to differ- 

 entiate marine bacteria from terrestrial bacteria are response to 

 temperature and response to the ionic concentration of their 

 environment, and consequently the remainder of this paper will 

 be concerned with recent work on the various facets of these 

 two characteristics of the marine phages isolated by myself. 



