TY - JOUR
T1 - Influence of Test Method Variables on Sensitivity of Neocloeon Triangulifer to a Reference Toxicant in Short-Term, Effluent Style Evaluations
AU - Soucek, David J.
AU - Dickinson, Amy
AU - Norberg-King, Teresa J.
N1 - The experiments described in the present study were conducted at the Illinois Natural History Survey (INHS; Champaign, IL, USA), when D. Soucek was employed there. The study was funded by a US Environmental Protection Agency (USEPA) Regional Applied Research Effort program grant by way of a Cooperative Ecosystem Studies Unit grant from the US Geological Survey (USGS) to D. Soucek at INHS. The authors thank T. Schmidt (USGS), K. Edly (USEPA), and R. Hockett (USEPA) for providing helpful comments on an early draft of this article.
The experiments described in the present study were conducted at the Illinois Natural History Survey (INHS; Champaign, IL, USA), when D. Soucek was employed there. The study was funded by a US Environmental Protection Agency (USEPA) Regional Applied Research Effort program grant by way of a Cooperative Ecosystem Studies Unit grant from the US Geological Survey (USGS) to D. Soucek at INHS. The authors thank T. Schmidt (USGS), K. Edly (USEPA), and R. Hockett (USEPA) for providing helpful comments on an early draft of this article.
PY - 2022/11
Y1 - 2022/11
N2 - Recent literature has demonstrated the sensitivity of mayflies to environmental contaminants. However, to date, there are no methods approved by the US Environmental Protection Agency for using sensitive insects like mayflies in whole-effluent toxicity or receiving water toxicity tests. The parthenogenetic mayfly Neocloeon triangulifer has been shown to be amenable to continuous culture in the laboratory, and methods have been described for its use in both acute and chronic toxicity studies. The goal of the present study was to investigate aspects of N. triangulifer testing and culturing methods that might require adjustment so that they are applicable for testing effluents and receiving waters in a short-term exposure. To this end, the influence of organism age, test duration, and test temperature on sensitivity to NaCl as a reference toxicant were tested (concentrations ranging from 182 to 2489 mg/L). Further studies were conducted to assess the utility of commercially available diets and the influence of nutrient amendment of water on organism growth and sensitivity. Seven-day NaCl tests started with less than 24-h-old larvae were similar in sensitivity to 14-day and full life chronic tests, and were much more sensitive than those started with 7-day-old organisms. Reducing test temperature from 25 °C to 22 °C had a minor influence on culture timing, and little impact on sensitivity to NaCl. In other experiments, reconstituted test water supplemented with nutrients to potentially improve in-test food quality had minimal effect on growth at 7 days and did not significantly alter acute sensitivity to NaCl relative to unamended reconstituted water. A suitable commercially available, ready-to-feed diet substitute for cultured diatoms was not found. Testing N. triangulifer in effluents or receiving waters with the methods recommended will complement similar methods for Ceriodaphnia dubia. Environ Toxicol Chem 2022;41:2758–2768.
AB - Recent literature has demonstrated the sensitivity of mayflies to environmental contaminants. However, to date, there are no methods approved by the US Environmental Protection Agency for using sensitive insects like mayflies in whole-effluent toxicity or receiving water toxicity tests. The parthenogenetic mayfly Neocloeon triangulifer has been shown to be amenable to continuous culture in the laboratory, and methods have been described for its use in both acute and chronic toxicity studies. The goal of the present study was to investigate aspects of N. triangulifer testing and culturing methods that might require adjustment so that they are applicable for testing effluents and receiving waters in a short-term exposure. To this end, the influence of organism age, test duration, and test temperature on sensitivity to NaCl as a reference toxicant were tested (concentrations ranging from 182 to 2489 mg/L). Further studies were conducted to assess the utility of commercially available diets and the influence of nutrient amendment of water on organism growth and sensitivity. Seven-day NaCl tests started with less than 24-h-old larvae were similar in sensitivity to 14-day and full life chronic tests, and were much more sensitive than those started with 7-day-old organisms. Reducing test temperature from 25 °C to 22 °C had a minor influence on culture timing, and little impact on sensitivity to NaCl. In other experiments, reconstituted test water supplemented with nutrients to potentially improve in-test food quality had minimal effect on growth at 7 days and did not significantly alter acute sensitivity to NaCl relative to unamended reconstituted water. A suitable commercially available, ready-to-feed diet substitute for cultured diatoms was not found. Testing N. triangulifer in effluents or receiving waters with the methods recommended will complement similar methods for Ceriodaphnia dubia. Environ Toxicol Chem 2022;41:2758–2768.
KW - Aquatic invertebrates
KW - aquatic toxicology
KW - invertebrate toxicology
UR - http://www.scopus.com/inward/record.url?scp=85138693259&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85138693259&partnerID=8YFLogxK
U2 - 10.1002/etc.5463
DO - 10.1002/etc.5463
M3 - Article
C2 - 35959890
AN - SCOPUS:85138693259
SN - 0730-7268
VL - 41
SP - 2758
EP - 2768
JO - Environmental Toxicology and Chemistry
JF - Environmental Toxicology and Chemistry
IS - 11
ER -