Experimental Studies On The Competition Between Artemia Franciscana And Two Strains Of Artemia Parthenogenetica

Competition experiments between Anemia franciscana and two strains of Anemia parthenogenetica (A. parthenogenetica o/Gahai and A. parthenogenetica of Chengkou) were carried out under different temperatures ( 15, 20 , 25 , 30 ) and different salinities (50, 100, 150, 200). These single-factor experiments were conducted in 2L-aquariums, designed with 5 replicates, and lasted for 150 days. The results are summarized as follows:When salinity was 100, the results of competition between A. franciscana and A. parthenogenetica of Gahai showed that at 15 , the sex ratio of competition treatments ranged from 1.36 to 1.95, A. franciscana had an advantage hi competition; at 20 , the two Artemia species coexisted with equal population in 2 replicates, and A. franciscana dominated hi the other 3 replicates; at 25 , A. franciscana won the competitionin 4 of the 5 replicates; at 30, A. franciscana won the competition (final sex ratio of each competition replicate fitted in with f/m=l :1)When temperature was 25 , the results of competition between A. franciscana and A. parthenogenetica of Gahai showed that under low (50) and high salinity (200), the final sex ratio of competition treatments fitted in with f/m=l:l, A. franciscana won the competition; under salinities of 100 and 150, 4 of the 5 replicates have the final sex ratio fitting in with f/m=l:l, A. franciscana won the competition; A. franciscana dominated in the remanent replicate of salinity 100, while in the remanent one of salinity 200, the two Artemia species coexisted with equal population.When salinity was 100, the results of competition between A. franciscana and A. parthenogenetica of Chengkou showed that both at 15 and 25 , 4 of the 5 replicates have the final sex ratio fitting in with f/m=l:l, A. franciscana won thecompetition; at 20 , the two Anemia species coexisted with equal population in 1 replicate, in the other three replicates A. franciscana dominated; at 30, A. franciscana won the competition in all 5 replicates, which sex ratio were fitting in withf/m=l:l.When temperature was 25, the results of competition between A. franciscana and A. parthenogenetica of Chengkou showed that the final sex ratio of competition treatments under salinity of 50 fitted in with f/m=l:l, A. franciscana won the competion; under salinities of 100, 150 and 200, the final sex ratio varied greatly among replicates: under salinity of 100, A. franciscana won the competition in 1 replicate and dominated in 2 replicates, A. parthenogenetica dominated in the other 2 replicates; under salinity of 150, A. franciscana dominated in 1 replicate, A. parthenogenetica dominated in 2 replicates, in the other replicates the two Artemia species coexisted with equal population; under salinity of 200, A. parthenogenetica dominated in 1 replicate, A. franciscana dominated in 2 replicates, in the other replicates the two Artemia species coexisted with equal population.