title: Responses of Takifugu obscurus fertilized eggs and larvae to increased ammonia exposure.
abstract: Ammonia is a common toxicant in aquatic systems; this substance has become a critical threat to fish, especially in early life stages. This study aimed to evaluate the effects of unionized ammonia (NH3-N: 0, 0.068, 0.138, 0.206, 0.275, 0.343, 0.412, and 0.481 mg L(-1)) on fertilized eggs and larvae of obscure puffer Takifugu obscurus, a fish species with potential economic value. Results showed that hatch time was significantly retarded and hatch rate was significantly decreased as NH3-N concentrations increased; newly hatched larvae exhibited high rate of abnormalities and low viability. The survival rate of larvae also decreased significantly as NH3-N concentrations increased; larvae could tolerate NH3-N to a less extent than embryos. NH3-N also caused a significant decrease in superoxide dismutase (SOD) and Na(+)/K(+) ATPase activities but not in malondialdehyde (MDA) levels of larvae. Two-way ANOVA indicated that there was a statistically significant interaction between NH3-N concentrations and exposure times on SOD activity but not on Na(+)/K(+) ATPase activity. Such responses indicated that an increase in ammonia concentration in surface water may negatively affect the early development of T. obscurus and thus likely impair population recruitment and persistence of this fish species.
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Jiangsu Institute of Freshwater Fisheries, 79 East Chating Street, Nanjing, 210017, China.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Li
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Nuo
authors.initials: N
authors.lastname: Xu
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Ziheng
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Lake and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China. chenyf@niglas.ac.cn.
authors.forename: Yafen
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000641:Ammonia / Q000633:toxicity*; D000818:Animals; D054750:Ecotoxicology; D004781:Environmental Exposure / Q000009:adverse effects*; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D023741:Takifugu / Q000196:embryology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015053:Zygote / Q000187:drug effects* / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D008315:Malondialdehyde; D000641:Ammonia; D013482:Superoxide Dismutase
keywords: Embryonic development; Hatch rate; Incubation period; Obscure puffer; Superoxide dismutase; Unionized ammonia