title: The evaluation of 3 diets for rearing Hyalella azteca and the influence of diet on acute ammonia toxicity.
abstract: Three Hyalella azteca cultures were reared on different diets since birth, reflecting the recommended diets of various investigators. The 3 diets consisted of fish flakes (FF), a mixture of fish flakes supplemented with the diatom Thalassiosira weissflogii (FF-D), and a mixture of fish flakes supplemented with yeast, cereal grass media, and trout chow (FF-YCT). The 3 diets were evaluated by comparing 20 wk of culturing data, along with the organism's response to standard 96-h toxicity testing with ammonium chloride over a range of pH and temperature. Hyalella azteca fed the FF-D diet had the highest overall survival rate (96.6%, standard deviation [SD] 4.3%) compared to those fed the FF diet (92.0%, SD 12.7%), or the FF-YCT diet (91.1%, SD 14.8%), although difference in survival was not statistically significant. Organisms fed the FF-D diet produced a higher number of young per week per adult (6.1, SD 2.8) than the FF diet (5.1, SD 2.2), or the FF-YCT diet (4.0, SD 1.2), although differences were not statistically significant. Of the diets evaluated, H. azteca reared on the FF-D diet were often significantly more resistant to total and un-ionized ammonia toxicity in acute 96-h testing than those reared on the other 2 diets across the 2 temperatures and 5 pHs tested, suggesting this may be the most optimal diet for this species. Environ Toxicol Chem 2016;35:2416-2424. © 2016 SETAC.
authors.affiliation: Environmental Sciences and Standards Division, Laboratory Services Branch, Ontario Ministry of the Environment and Climate Change, Etobicoke, Ontario, Canada. lisa.kennedy@ontario.ca.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Kennedy
authors.affiliation: Environmental Sciences and Standards Division, Laboratory Services Branch, Ontario Ministry of the Environment and Climate Change, Etobicoke, Ontario, Canada.
authors.forename: Trudy L
authors.initials: TL
authors.lastname: Watson-Leung
authors.affiliation: Environmental Sciences and Standards Division, Laboratory Services Branch, Ontario Ministry of the Environment and Climate Change, Etobicoke, Ontario, Canada.
authors.forename: David G
authors.initials: DG
authors.lastname: Poirier
mesh_terms: D000641:Ammonia / Q000633:toxicity*; D033304:Amphipoda / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D000818:Animals; D004032:Diet; D005260:Female; D063427:Food Quality; D006863:Hydrogen-Ion Concentration; D012098:Reproduction / Q000187:drug effects; D013696:Temperature; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D000641:Ammonia
keywords: Ammonia; Diet; Hyalella azteca; Standardization; Toxicity Testing