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Avoidance response by shrimps to a copper gradient: does high population density prevent avoidance of contamination?

A new interesting article has been published in Environ Toxicol Chem. 2018 Sep 25. doi: 10.1002/etc.4277. and titled:

Avoidance response by shrimps to a copper gradient: does high population density prevent avoidance of contamination?

Authors of this article are:
Araújo CVM Pereira KC Blasco J.

A summary of the article is shown below:
Bioassays using the non-forced exposure approach have shown to be a relevant tool that might complement the traditional ecotoxicological risk assessment. As the non-forced exposure approach is based on spatial displacement of organisms and the consequent habitat selection processes, the population density might play an important role in the decision of avoiding or preferring an ecosystem. Therefore, the aim of the present study was to assess if the avoidance response to contamination, measured in a non-forced exposure system, is density-dependent and how determinant contamination could be for the habitat selection process in comparison with the population density. The freshwater shrimp Atyaephyra desmarestii was exposed to a copper gradient in a non-forced exposure system formed by seven interconnected compartments (total volume: 600 mL), which contained different copper concentrations. The density treatments used were: 3, 5 and 10 organisms per compartment that correspond to 0.5, 0.8 and 1.7 organisms per 100 mL, respectively. Clearly, the avoidance response to copper was more intense in the population with the lower density: the highest population density showed the lowest avoidance. The AC50 values (concentration that triggers an avoidance of 50% of the population) were: 47, 134 and 163 µg · L-1 . In summary, it was observed that shrimps were able to detect and avoid potentially toxic copper concentrations, but the avoidance response was affected by population density. This article is protected by copyright. All rights reserved.

Check out the article’s website on Pubmed for more information:



This article is a good source of information and a good way to become familiar with topics such as: contamination gradient;non-forced exposure system;population density;sensitivity;spatial avoidance.

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