Behavior persistence in defining threshold switch in stepwise response of aquatic organisms exposed to toxic chemicals.
As a characteristic in bacterial colony, persistence model described the dynamics of two subpopulations (normal (n) and persister (p)). In order to illustrate the switch of "Threshold" in the stepwise behavior responses of organisms, it is hypothesized that total behavior (Bt) of organisms consists of two types in behavior tendency, intoxication (Bp) and normal/recovery behavior (Bn). Both Bpand Bncould be concurrently affected by environmental stress E, and behavior response modes (M) are decided by the relationship between E and toxicity threshold of test organisms (Ti). The results suggested stress constant λ was decided by the constant rates gnE,gpE, anand ap. Due to different stress constant λ, the behavior responses of indicators showed great difference in different M, which included 'safe mode' (Ms), 'acclimation mode' (Mac), 'adjustment mode' (Maj) and 'toxic effect' (Mte). Usually, Btduring Mscould maintain around 0.8, and Mtewould happen once it is lower than 0.2. According to the relationship between Btvalues and E changes in 7 Majs, behavior persistence relying on adjustment could reflect the behavior homeostasis of organisms under environmental stress and be regarded as a threshold switch for the stepwise behavior responses. The mathematical analysis of behavior persistence allows making a quantitative prediction on environment assessment that would promote the emergence of persistence, as well as evaluating its ecological implications.
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China. Electronic address: zmren@sdnu.edu.cn.
Zongming
Z
Ren
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China.
Shangge
S
Li
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China.
Tingting
T
Zhang
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China.
Luhuizi
L
Qi
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China.
Na
N
Xing
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China.
Huimin
H
Yu
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China.
Jinfeng
J
Jian
Department of Biological Sciences, Pusan National University, Busan 609735, Republic of Korea; Ecology and Future Research Association, Busan 609802, Republic of Korea.
Tae-Soo
TS
Chon
Institute of Environment and Ecology, Shandong Normal University, Ji'nan 250014, PR China. Electronic address: tangb@sdnu.edu.cn.
Bo
B
Tang
D000465:Algorithms; D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects*; D001419:Bacteria / Q000187:drug effects*; D008962:Models, Theoretical; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D014874:Water Pollutants, Chemical
Behavior strength; Environmental stress; Homeostasis; Persistence model; Stepwise behavior response