Mechanisms behind interactive effects of temperature and bifenthrin on the predator avoidance behaviors in parr of chinook salmon (Oncorhynchus tshawytscha)

Transcriptomic and Histopathological Effects of Bifenthrin to the Brain of Juvenile Rainbow Trout (Oncorhynchus mykiss)

“…Subsequently, the increased use of pyrethroid insecticides, such as bifenthrin, since the mid-2000 s, coincided with decreased migratory returns in these spawning waters and may also be contributing to the POD [14][15][16][17][18]. Concentrations of bifenthrin in water samples collected from the Delta have been detected above acute and chronic benchmark values for several aquatic invertebrate and fish species (>1.3 and >40 ng/L, respectively) [10,19], and well above levels reported to dysregulate neuroendocrine function (≤1.5 µg/L) [20][21][22] and induce neurotoxicity in salmonids (≤120 ng/L) [23,24].…”

“…Water samples collected (in duplicate, 1 L samples) from exposure tanks after 24 hours (h), 7 days (d), and 14 d were stored at 4 • C in amber glass bottles and extracted within two weeks following initial sample collection by liquid-liquid extraction. Bifenthrin extractions were conducted as previously reported [22]. Samples were analyzed using an Agilent gas chromatograph (6850A) and mass spectrometer (5975C; Santa Clara, CA, USA) in methane negative ionization mode.…”

“…The primary mode of action for bifenthrin is binding to and disrupting voltagegated Na + channels, impairing neuronal function by altering the release of neurotransmitters [25][26][27]. Bifenthrin is a known endocrine disruptor in fish [28][29][30][31][32], dysregulating the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-thyroid (HPT) axis in salmonids by acting upon the dopaminergic pathway [20][21][22]31]. Bifenthrin is also capable of dysregulating Ca 2+ homeostasis by impairing signaling molecules, as recently reported in inland silversides (Menidia beryllina) and zebrafish (Danio rerio) following bifenthrin treatment (<10 ng/L) [33,34].…”

Temperature increase and its effects on fish stress physiology in the context of global warming

“…In the long term, these stress responses inhibit energy allocation to biological processes such as immunity, growth and reproduction, also called tertiary responses. Normal arrows represent an activation while bar-headed arrows represent an inhibition study, however, temperatures of 5 and 8 C had no effect on brain DA levels when compared to fish reared at 2 C. By contrast, exposure to higher temperature for 2 weeks (19 vs. 16 and 11 C) induced a decrease of DA level in the brain of Chinook salmon Oncorhynchus tshawytscha (Walbaum 1792) (Giroux et al, 2019). This suggests that the response of the dopaminergic system to a temperature shift may depend on various different factors, such as duration of exposure, extent of temperature change and species under study.…”

“…By contrast, exposure to higher temperature for 2 weeks (19 vs . 16 and 11°C) induced a decrease of DA level in the brain of Chinook salmon Oncorhynchus tshawytscha (Walbaum 1792) (Giroux et al ., 2019). This suggests that the response of the dopaminergic system to a temperature shift may depend on various different factors, such as duration of exposure, extent of temperature change and species under study.…”