FISHERY BULLETIN: VOL. 69. NO. 3 



bactericidal response against o;ram-negative ba- 

 cilli was reached within 48 hr after inoculation, 

 and high titers persisted throughout the obser- 

 vation period (11 days). In spiny lobsters, 

 presumably maintained at significantly higher 

 environmental temperatures at Bimini, the 

 Bahamas (reported as 26° -28° C in a later pa- 

 per) , the primary bactericidal response to intra- 

 cardial injection of living or killed suspensions of 

 the same gram-negative bacilli (originally iso- 

 lated from the digestive tract of spiny lobsters) 

 reached a peak at about 36 to 48 hr after in- 

 jection, then declined slowly for the following 2 

 weeks. Partial lack of specificity of the bac- 

 tericidin was indicated by its appearance follow- 

 ing injection of gram-positive bacilli and by its 

 activity against Salmonella typhosa and Esch- 

 erichia coli, as well as against the unidentified 

 gram-negative bacillus used as the homologous 

 test organism. The bactericidin was not active, 

 however, against Pseudomonas aeruginosa or 

 against three species of gram-])ositive bacteria. 



A subsequent study (Weinheimer, Acton, 

 Sawyer, and Evans, 1969) of the specificity of 

 the spiny lobster bactericidin further indicated 

 that the response was i^artially nonspecific. Low 

 titers of the bactericidin against gram-negative 

 bacilli could be demonstrated after injections of 

 Formalin-killed type 2 pneumococci and bovine 

 serum albumin. Formalin produced a pro- 

 nounced adjuvant efl:ect. 



Secondary responses — those following rein- 

 jection of the same antigen after a lapse of time 

 — of spiny lobsters to killed suspensions of gram- 

 negative bacilli were also examined by Evans, 

 Gushing, Sawyer, Weinheimer, Acton, and Mc- 

 Neely (1969). Titers of bactericidin were 

 slightly but significantly higher after reinocula- 

 tion than after primary inoculation, and the rate 

 of secondary response (the number of hours to 

 I'each peak titer) seemed somewhat accelerated 

 when comi)ared with the primary response. Un- 

 fortunately, the number of animals tested was 

 small. It seems important that similar obser- 

 vations be greatly extended — since, as the au- 

 thors pointed out, the results were reminiscent 

 of the specific anamnesis or immunological mem- 

 ory demonstrable in the immunoglobulin 

 responses of vertebrates. 



The spiny lobster bactericidin was apparently 

 a large molecule, as suggested by resistance to 

 dialysis and by Sephadex separations. Inacti- 

 vation occurred at 65° C and activity was not 

 restored by addition of unheated normal hemo- 

 lymph. Activity was not reduced by treatment 

 with EDTA or carageenin. These results indi- 

 cate dissimilarity with vertebrate comiilement- 

 based bactericidal systems, but the authors sug- 

 gested that the bactericidin may represent a 

 primordial immunoglobulin. 



Noteworthy is that all the American lobsters 

 and a number of the West Indian sjiiny lobsters 

 used in the studies by Evans, Weinheimer. Paint- 

 er, Acton, and Evans (1969) had demonstrable 

 pre-existing titers of bactericidins against the 

 gram-negative bacillus used in the experiments. 

 Possibly the remainder of the sijiny lobsters used 

 in the studies could have had titers of bacteri- 

 cidins lower than were demonstrable by the 

 methods used. Thus inoculation may not have 

 "induced" the bactericidin but instead may have 

 merely enhanced or increased the titers. A num- 

 ber of explanations were offered for the pre-ex- 

 isting titers of bactericidal activit.v, including 

 trauma because of handling, and response to pre- 

 vious bacterial infection. Two relevant obser- 

 vations are that in many American lobsters, a 

 rapid increase in bactericidal titer preceded 

 death, and in studies of spiny lobsters, the bac- 

 tericidal activity was found to be partially non- 

 specific, in that activity against other gram- 

 negative bacteria was enhanced. 



The conclusions reached by the research group 

 that examined the spiny lobster bactericidin 

 (Weinheimer, Acton, Sawyer, and Evans. 1969) 

 are in accord with findings for other phyla: 

 "These data suggest that, although invertebrates 

 appear capable of antigenic recognition, the mol- 

 ecules synthesized may have broad specificity 

 covering a wide range of antigenic determinants. 

 Further studies will be necessary to ascertain 

 whether these inducible substances represent 

 primitive immunoglobulins. In any event, it 

 would be surprising if they did not have a major 

 role in defense of the animal against pathogenic 

 microbes." 



An important qualification was pointed out by 

 Aarum (1967) regarding results obtained by ex- 



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