@article{wang_kunz_hardesty_steevens_norberg-king_hammer_bauer_augspurger_dunn_martinez_et al._2021, title={Method Development for a Short-Term 7-Day Toxicity Test with Unionid Mussels}, volume={40}, DOI={10.1002/etc.5225}, abstractNote={The US Environmental Protection Agency's short-term freshwater effluent test methods include a fish (Pimephales promelas), a cladoceran (Ceriodaphnia dubia), and a green alga (Raphidocelis subcapitata). There is a recognized need for additional taxa to accompany the three standard species for effluent testing. An appropriate additional taxon is unionid mussels because mussels are widely distributed, live burrowed in sediment and filter particles from the water column for food, and exhibit high sensitivity to a variety of contaminants. Multiple studies were conducted to develop a relevant and robust short-term test method for mussels. We first evaluated the comparative sensitivity of two mussel species (Villosa constricta and Lampsilis siliquoidea) and two standard species (P. promelas and C. dubia) using two mock effluents prepared by mixing ammonia and five metals (cadmium, copper, nickel, lead, and zinc) or a field-collected effluent in 7-day exposures. Both mussel species were equally or more sensitive (more than two-fold) to effluents compared with the standard species. Next, we refined the mussel test method by first determining the best feeding rate of a commercial algal mixture for three age groups (1, 2, and 3 weeks old) of L. siliquoidea in a 7-day feeding experiment, and then used the derived optimal feeding rates to assess the sensitivity of the three ages of juveniles in a 7-day reference toxicant (sodium chloride [NaCl]) test. Juvenile mussels grew substantially (30%-52% length increase) when the 1- or 2-week-old mussels were fed 2 ml twice daily and the 3-week-old mussels were fed 3 ml twice daily. The 25% inhibition concentrations (IC25s) for NaCl were similar (314-520 mg Cl/L) among the three age groups, indicating that an age range of 1- to 3-week-old mussels can be used for a 7-day test. Finally, using the refined test method, we conducted an interlaboratory study among 13 laboratories to evaluate the performance of a 7-day NaCl test with L. siliquoidea. Eleven laboratories successfully completed the test, with more than 80% control survival and reliable growth data. The IC25s ranged from 296 to 1076 mg Cl/L, with a low (34%) coefficient of variation, indicating that the proposed method for L. siliquoidea has acceptable precision. Environ Toxicol Chem 2021;40:3392-3409. © 2021 SETAC.}, number={12}, journal={ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY}, author={Wang, Ning and Kunz, James L. and Hardesty, Douglas K. and Steevens, Jeffery A. and Norberg-King, Teresa and Hammer, Edward J. and Bauer, Candice R. and Augspurger, Tom and Dunn, Suzanne and Martinez, David and et al.}, year={2021}, month={Nov}, pages={3392–3409} } @article{popp_cope_mcgregor_kwak_augspurger_levine_koch_2018, title={A Comparison of the chemical sensitivities between in vitro and in vivo propagated juvenile freshwater mussels: Implications for standard toxicity testing}, volume={37}, ISSN={0730-7268}, url={http://dx.doi.org/10.1002/etc.4270}, DOI={10.1002/etc.4270}, abstractNote={Abstract Unionid mussels are ecologically important and are globally imperiled. Toxicants contribute to mussel declines, and toxicity tests using juvenile mussels—a sensitive life stage—are valuable in determining thresholds used to set water quality criteria. In vitro culture methods provide an efficient way to propagate juveniles for toxicity testing, but their relative chemical sensitivity compared with in vivo propagated juveniles is unknown. Current testing guidelines caution against using in vitro cultured juveniles until this sensitivity is described. Our objective was to evaluate the relative sensitivity of juvenile mussels produced from both in vitro and in vivo propagation methods to selected chemicals. We conducted 96‐h acute toxicity tests according to ASTM International guidelines with 3 mussel species and 6 toxicants: chloride, nickel, ammonia, and 3 copper‐based compounds. Statistically significant differences between in vitro and in vivo juvenile 96‐h median effect concentrations were observed in 8 of 17 tests, and in vitro juveniles were more sensitive in 6 of the 8 significant differences. At 96 h, 4 of the 8 statistically different tests for a given chemical were within a factor of 2, which is the intralaboratory variation demonstrated in a recent evaluation of mussel toxicity tests. We found that although differences in chemical sensitivity exist between in vitro and in vivo propagated juvenile mussels, they are within normal toxicity test variation. Therefore, in vitro propagated juvenile mussels may be appropriate for use in ASTM International‐based toxicity testing. Environ Toxicol Chem 2018;37:3077–3085. © 2018 SETAC}, number={12}, journal={Environmental Toxicology and Chemistry}, publisher={Wiley}, author={Popp, Anakela and Cope, W. Gregory and McGregor, Monte A. and Kwak, Thomas J. and Augspurger, Tom and Levine, Jay F. and Koch, Leroy}, year={2018}, month={Nov}, pages={3077–3085} }