organized according to the plan of a full factor experiment (FFE-2^), 

 the experimental object was the Balanus , the factors were the 

 Vorticella , tenellia and hydroid. In accordance with the planning 

 matrix, each factor was represented at two levels: the upper (+) and 

 lower (-) levels. For the Tenellia and hydroid, the lower level 

 represents absence of the species in the corresponding versions of the 

 FFE, while the upper level represents its presence. The Vorticella , in 

 versions with a lower level, was periodically eliminated. The plan and 

 results of the experiment are presented in Fig. 7. As we can see from 

 the graph, significant suppression of the Balanu s is observed only in 

 those versions in which the hydroid developed; tHe hydroid and 

 Vorticella developed well only when the Tenellia were absent, while a 

 high population of Tenellia was formed where the hydroid was present and 

 the Vorticella was periodically eliminated. 



The results of the experiment allowed us to calculate the relative 

 intensity (ratio of value of partial effects to results of experiment in 

 those versions in which effect of given connections has been revealed) 

 of the connections which we modeled (Table 9). It was found that the 

 coefficients of relative effectiveness C for the various connections are 

 not the same, and change from comparatively small positive to high 

 negative values. For bilateral connections, the two coefficients of 

 relative intensity differed not only in magnitude, but also (in two 

 cases) in sign. The higher the value of negative coefficient C, the 

 greater the suppression of the dependent species; the higher the value 

 of the positive coefficient, the more favorable the conditions for 

 development of the dependent species; the lower the modulus of 

 coefficient C, the weaker the effect of the connection. 



The values of coefficients of relative intensity produced for the 

 connections modeled were compared with the characteristics of 

 development of the animals or the status of the populations. To do 

 this, using the results of the FFE, we calculated the specific rate of 

 weight increase (C^) of the Balanus and hydroids. We found that the 

 specific rate of growth of the Balanus changed as a function of the 

 specific growth rate of the hydroid (Fig. 8). The suppression of the 

 Balanus was weakest when the three-member connection 7a was functioning 

 (Fig. 7 , version 8) with C^ of the hydroid less than 0.3. An increase 

 in the specific growth rate of the hydroid to about 0.4 was accompanied 

 by a severe inhibition of the growth of the Balanus . Comparison of the 

 coefficients c of the connections of complex I with the values of C„ for 

 the hydroid showed that the growth rate of the Balanus , with low growth 

 rate of the hydroid (less than 0.3), was determined by the conditions 

 under which the animals were maintained. With a further increase in C^ 

 of the hydroid, the effect of symphysiologic connections appeared, the 

 intensity of which increased with an increase in the growth rate of the 

 hydroid. In turn, the specific growth rate of the hydroid changed as a 

 function of the Tenellia population (connection of complex II). Eating 

 the hydroid, the Tenellia constantly damages the hydranths, penetrating 

 their cover and sucking out the plasma. The damaged hydranths 

 regenerate after 3 or 4 days, but until this happens, the total food 

 intake of the hydroid colony decreases, and its growth is slowed. The 

 frequency of damage, obviously, is related to the population density of 

 the Tenellia , which can be estimated by the weight of the hydroid colony 



194 



