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- Jaensson, Alia, 1971-, et al.
(författare)
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Effects of a pyrthroid pesticide on endocrine reponses to female odour and reproductive behaviour in male parr of brown trout (Salmo trutta)
- 2007
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Ingår i: Aquatic Toxicology. - : Elsevier. - 0166-445X .- 1879-1514. ; 81:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Reproductive behaviour of brown trout (Salmo trutta L.) from an anadromous stock was studied in a large stream water aquarium. Four adult males and two ovulated females were placed in the aquarium together with eight mature male parr. Four of the parr were exposed during the previous 4 days to two concentrations (0.1 or 1.0 μg l−1) of the pyrethroid pesticide cypermethrin (a disrupter of olfactory receptor function) and four of the parr to the solvent ethanol. The behaviour of all fish was followed for 24 h and then blood and milt was collected. Exposure to the higher concentration of cypermethrin disturbed the reproductive behaviour of the parr. They displayed fewer courting events, spent less time near the nesting females and had lower volumes of strippable milt. They also had significantly lower amounts of 11-ketotestosterone (11-KT) in the blood plasma than the control group. The higher cypermethrin group also had significantly lower levels of all these variables than the lower cypermethrin group, apart from strippable milt that showed no significant differences between two groups. No significant differences in non-reproductive behaviours were observed between any of the groups. In the control fish, there were significant positive correlations between (a) the number of courting events and the amount of time spent near the female, (b) blood plasma levels of 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) and time spent near the female and (c) plasma levels of 17,20β-P and the number of courting events. Further, in control fish, higher plasma levels of 17,20β-P were observed in parr interacting with a female compared to those with no female contacts. A priming experiment confirmed a previous study that cypermethrin damages olfactory reception. Parr exposed to cypermethrin had significantly lower blood plasma levels of 17,20β-P and 11-KT than control males after exposure to ovarian fluid and urine (known to contain reproductive priming pheromones). When ethanol-exposed males were exposed to ovarian fluid and urine they had significantly higher plasma levels of 17,20β-P compared to those exposed to water only.
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| 2. |
- Jaensson, Alia, et al.
(författare)
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Effects of copper on olfactory-mediated endocrine responses and reproductive behaviour in mature male brown trout Salmo trutta parr to conspecific females
- 2010
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 76:4, s. 800-817
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the effects of copper (CuSO4) on the ability of mature male brown trout Salmo trutta parr to detect and react both physiologically and behaviourally to female pheromones were studied. The study was composed of two parts. In the first experiment, priming effects of the female pheromone prostaglandin F2α (PGF2α) were evaluated by determining the amount of milt produced and the blood plasma levels of 11-ketotestosterone (11-KT) and 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) after the PGF2α exposure. In the second experiment, male parr were placed in a large stream tank together with a group of adult males and ovulated females and their individual behaviours were recorded. In the priming experiment, the amount of expressible milt was significantly lower, less than half, in groups exposed during 4 days to 10 or 100 µg l−1 copper compared with control parr only exposed to water. No significant differences were observed in plasma levels of 11-KT and 17, 20β-P. During the behavioural experiment, exposed parr spent less time with the female and had a lower number of courting events. Blood plasma levels of 11-KT were, however, significantly higher in the group exposed to 100 µg l−1 copper compared with the control group. Furthermore, the exposed group spent significantly less time swimming upstream than did the control group. The present study demonstrates that exposure to copper affects reproductive behaviours and endocrinology of S. trutta male parr.
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| 5. |
- Jaensson, Alia, 1971-
(författare)
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Pheromonal Mediated Behaviour and Endocrine Responses in Salmonids : The impact of Cypermethrin, Copper, and Glyphosate
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The effects of cypermethrin, copper and glyphosate on the endocrine system and subsequent response to female pheromones were investigated in mature male brown trout (Salmo trutta) parr. Responses measured were the amount of strippable milt, blood plasma levels of both an androgen (11-ketotestosterone (11-KT)) and a progestin (17α,20β-dihydroxy-4-pregnen-3-one (17,20b-P)), and behavioural changes. This was done in a two phased investigation where parr were exposed to one of the following via ambient water: 1) 0.1 or 1.0 μg L-1 cypermethrin, 2) 10 or 100 μg L-1 copper (Cu2+), or 3) 150 μg L-1 glyphosate for a 96 hour period. Phase one was a priming experiment exposing parr to a treatment followed by priming with PGF2α or ovarian fluid (OVF). Atlantic salmon (Salmo salar) parr were, also exposed to glyphosate during phase I. The second phase was centered on behavioural observations. Exposed parr were placed in a 35,000 L stream aquarium together with two ovulated females and four anadromous males. After the experiments a blood sample was taken, milt volumes measured and testes weighed. The plasma was analyzed for 11-KT and 17,20b-P concentrations using radioimmunoassay (RIA). Results from phase I-priming: 1.0 μg L-1 cypermethrin exposure lowered 17,20b-P and 11-KT; Copper exposure lowered milt volumes; glyphosate exposure lowered 11-KT in salmon and raised 17,20b-P in trout. Results from phase II-behaviour: 1.0 μg L-1 cypermethrin exposure lowered 11-KT, milt and spawning behaviour; copper exposure lowered spawning behaviour and raised 11-KT; Glyphosate exposure lowered 11KT; continuous cypermethrin exposure raised 17,20b-P, 11-KT and gave a tendency towards increased aggression. It is concluded that low concentration exposure to the compounds examined can induce negative effects on male salmonid endocrine systems, either through a disruption in the olfactory system or through a direct effect.
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