<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The purpose of this study was to investigate the sublethal Co toxicity on rainbow trout (<italic>Oncorhynchus mykiss</italic>). Trout were exposed to Co and selected parameters were evaluated at intervals of 1, 15 and 30 days. Fish exposed to higher levels of Co grew slower than fish exposed to lower levels of Co. Weight gain, specific growth rate (SGR) decreased linearly with the increase of cobalt in the water. The body condition factor (CF) of fish reared in water with low cobalt concentration decreased substantially but this decrease was not significant for fish exposed to higher cobalt concentration. The values of the feed conversion ratio (FCR) increased in fish exposed to higher levels of Co. Co significantly changed the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and decreased at day 30, and in both cases this decrease was more remarkable at day 15 so that the level of AST and ALT reached the control value at day 30. The alkaline phosphatase (ALP) level also showed a remarkable 15-day decline. There was a significant increase in glucose (G) concentration in both Co-exposed groups on day 15. However, serum cholesterol (Chl) was significantly reduced on day 15 and increased on day 30; there were no significant differences in both exposed Co-groups. The triglyceride (TG) level also decreased substantially. There was no regular pattern of total protein (TP) in the serum, so that no significant differences were found in the level of TP between low and high-exposed fish. In summary, this study suggests that exposure of essential trace elements such as cobalt may change growth and biochemical parameters, and that measurement of these parameters may be used in toxicological studies to determine the general health status of fish.</p></abstract>

The purpose of this study was to investigate the sublethal Co toxicity on rainbow trout (Oncorhynchus mykiss). Trout were exposed to Co and selected parameters were evaluated at intervals of 1, 15 and 30 days. Fish exposed to higher levels of Co grew slower than fish exposed to lower levels of Co. Weight gain, specific growth rate (SGR) decreased linearly with the increase of cobalt in the water. The body condition factor (CF) of fish reared in water with low cobalt concentration decreased substantially but this decrease was not significant for fish exposed to higher cobalt concentration. The values of the feed conversion ratio (FCR) increased in fish exposed to higher levels of Co. Co significantly changed the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and decreased at day 30, and in both cases this decrease was more remarkable at day 15 so that the level of AST and ALT reached the control value at day 30. The alkaline phosphatase (ALP) level also showed a remarkable 15-day decline. There was a significant increase in glucose (G) concentration in both Co-exposed groups on day 15. However, serum cholesterol (Chl) was significantly reduced on day 15 and increased on day 30; there were no significant differences in both exposed Co-groups. The triglyceride (TG) level also decreased substantially. There was no regular pattern of total protein (TP) in the serum, so that no significant differences were found in the level of TP between low and high-exposed fish. In summary, this study suggests that exposure of essential trace elements such as cobalt may change growth and biochemical parameters, and that measurement of these parameters may be used in toxicological studies to determine the general health status of fish.

Sublethal Cobalt Toxicity Effects on Rainbow Trout (<italic>Oncorhynchus mykiss</italic>)

Croatian Journal of Fisheries

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Sublethal Cobalt Toxicity Effects on Rainbow Trout ()

The purpose of this study was to investigate the sublethal Co toxicity on rainbow trout (Oncorhynchus mykiss). Trout were exposed to Co and selected parameters...

Sublethal Cobalt Toxicity Effects on Rainbow Trout (Oncorhynchus mykiss)

Published Online: Dec 21, 2019

Page range: 243 - 252

Received: Jun 03, 2019

Accepted: Oct 17, 2019

DOI: https://doi.org/10.2478/cjf-2019-0018

Keywords
Rainbow trout, Heavy metals, Cobalt, Growth, Biochemical parameters

© 2019 Fereshteh Nasri et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Sublethal Cobalt Toxicity Effects on Rainbow Trout (Oncorhynchus mykiss)

Published Online: Dec 21, 2019

Page range: 243 - 252

Received: Jun 03, 2019

Accepted: Oct 17, 2019

DOI: https://doi.org/10.2478/cjf-2019-0018

KeywordsRainbow trout, Heavy metals, Cobalt, Growth, Biochemical parameters

© 2019 Fereshteh Nasri et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Rainbow trout, Heavy metals, Cobalt, Growth, Biochemical parameters