Exposure to carbamate fungicide iodocarb does not affect reproductive behavior or milt volumes in precocious male brown trout (Salmo trutta L.) parr

K Håkan Olsén,Hanna L Olsén

doi:10.1007/s10695-020-00803-x

Abstract

Previous studies with olfactory-disturbing pesticides resulted after exposure in disturbed behavior and physiology in fish. In the present experiment, reproductive behavior and milt volumes of precocious brown trout (Salmo trutta L.) male parr were studied in a large stream aquarium after exposure to the olfactory-disturbing fungicide 15 μg l−1 IPBC (iodocarb; 3-iodo-2-propynyl butyl carbamate) for 96 h. The statistical analyses did not reveal any significant differences for time attending females between controls and IPBC-exposed males. Furthermore, there were no significant differences in milt volumes. However, when taking all fish into consideration, there were significant differences in milt volumes between parr that had been attending females and those had not been attending females. Controls that had attended females had significantly higher milt volumes than controls or IPBC-exposed males that had not attended females. Taking all control and IPBC parr into consideration, there was a statistically significant positive correlation between time attended females and volume of milt and gonadosomatic index (GSI), respectively. In summary, 15 μg l−1 IPBC did not have any significant effects on mature male parr reproductive behavior and milt volumes.

Highlights

Various types of pesticides are present in surface water, and there are concerns about their effects on aquatic organisms (e.g., Fulton et al 2014; Hessel et al 1997; Solomon et al 2014)
The aim of the present study was to investigate whether the olfactory-disturbing fungicide IPBC can affect mature male brown trout parr reproductive behavior and milt volumes
There were no significant differences for the time attending females between the exposures (MW U = 111, P > 0.05; N1 = N2 = 15)

Summary

Introduction

Various types of pesticides are present in surface water, and there are concerns about their effects on aquatic organisms (e.g., Fulton et al 2014; Hessel et al 1997; Solomon et al 2014). Electro-physiological studies (electro-olfactogram, EOG) have shown that some pesticides reduce the olfactory response to the amino acids L-serine and Lhistidine in juvenile coho salmon (Oncorhynchus kisutch) and rainbow trout (O. mykiss) (Jarrard et al 2004; Tierney et al 2006a, 2007). The carbamate fungicide IPBC (iodocarb; 3-iodo-2-propynyl butyl carbamate) was the most potent of the 10 compounds tested It is used in antisapstain formulations in the forestry industry and in treatment of fresh lumber and during water runoff and can result in IPBC contamination of aquatic environments (Juergensen et al 2000). IPBC reduced EOG responses and preferences for L-histidine at concentrations as low as 1 μg l−1, about 100 times lower than the 96-h LC50 value for the most sensitive stage in juvenile coho salmon and rainbow trout (Bailey et al 1999; Farrell et al 1998). No observed effect concentration (NOEC) for juvenile coho salmon was set to < 0.70 mg l−1 (Farrell et al 1998)

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Conclusion