[Adaptability of Moina affinis (Crustacea: Cladocera: Moinidae) to seawater salinity].
By the methods of experimental ecology, this paper studied the effects of different salinity (0, 1, 2, 3, 4, 5) on the survival, growth, and reproduction of Moina affinis (Crustacea: Cladocera: Moinidae) at 25 degrees C +/- 0.5 degrees C under laboratory conditions, aimed to know the adaptability of freshwater cladocerans to seawater salinity. The results indicated that when the salinity increased from 0 to 5, the mean lifespan of M. affinis was 16.8 +/- 1.3, 17.8 +/- 3.5, 14.2 +/- 5.7, 13.0 +/- 1.6, 9.6 +/- 1.5 and 6.6 +/- 1.8 days, intrinsic increase rate (rm) was 0.91 +/- 0.01, 0.96 +/- 0.01, 0.86 +/- 0.10, 0.86 +/- 0.05, 0.49 +/- 0.18 and 0.24 +/- 0.06 d (-1) mean eggs production per clutch was 34.5 +/- 3.7, 34.2 +/- 3.9, 27.5 +/- 7.1, 34.6 +/- 3.9, 12.3 +/- 5.0 and 9.1 +/- 2.1 ind., and life fecundity was 410 +/- 32, 445 +/- 84, 250 +/- 106, 294 +/- 47, 59 +/- 38 and 24 +/- 6 ind., respectively. There was a significant difference in mean lifespan, intrinsic increase rate, and mean eggs production per clutch between treatments salinity 0, 1, 2 and 3 and treatments salinity 4 and 5, and in life fecundity between treatments salinity 0 and 1 and treatments salinity 2, 3, 4 and 5. The body length and daily growth rate was lower in control than in other treatments. It was suggested that salinity 5 was the maximum threshold salinity for the survival and reproduction of M. affinis, but after a short period of acclimatization in diluted seawater, the maximum threshold could reach 6. 5.
Zhao
Wen
W
Key Laboratory of Hydrobiology in Liaoning Province' s Universities, Dalian Fisheries University, Dalian 116023, China. zhaowen@dlfu.edu.cn
Yu
Boshi
B
Wang
Ting
T
Song
Liang
L
D000064:Acclimatization; D000223:Adaptation, Psychological; D000818:Animals; D033361:Cladocera / Q000254:growth & development / Q000502:physiology*; D012098:Reproduction / Q000502:physiology; D012623:Seawater