title: Ammonia toxicity as a criterion for the evaluation of larval quality in the prawn Macrobrachium rosenbergii.
abstract: The feasibility of a short-term ammonia toxicity test as an evaluation criterion for larval quality was assessed in three trials. In each one, Macrobrachium rosenbergii larvae originating from the same spawn were nutritionally differentiated in two groups by feeding them either a nutrient-rich (Artemia nauplii enriched for 24 h with n-3 highly unsaturated fatty acids (HUFA) and ascorbic acid (AA)) or a nutrient-poor diet (Artemia nauplii starved for 24 h). Throughout their development, larvae from both treatments were exposed during 24 h to six concentrations of total ammonia (NH(4)(+)+NH(3)) and a control (no ammonia added). Based on mortality rates, the median lethal concentration for 50% of the population (LC(50)) was estimated. As expected from earlier work, larvae fed the optimal diet presented higher n-3 HUFA and AA contents as well as higher growth and metamorphosis rates. From the moment the effect of diet quality was analytically detectable in the tissues of the larvae, the ammonia test was able to distinguish both groups of larvae. Differences in ammonia tolerance were observed as early as larval stage 4 and remained evident throughout larval development. The short-term ammonia toxicity test proved to be a valuable, sensitive and reproducible criterion for the establishment of larval quality.
authors.affiliation: Laboratory of Aquaculture and Artemia Reference Center, University of Gent, Rozier 44, 9000 Ghent, Belgium. ronaldo.cavalli@rug.ac.be
authors.forename: R O
authors.initials: RO
authors.lastname: Cavalli
authors.forename: E V
authors.initials: EV
authors.lastname: Berghe
authors.forename: P
authors.initials: P
authors.lastname: Lavens
authors.forename: T T
authors.initials: TT
authors.lastname: Nguyen
authors.forename: M
authors.initials: M
authors.lastname: Wille
authors.forename: P
authors.initials: P
authors.lastname: Sorgeloos
mesh_terms: D000367:Age Factors; D000641:Ammonia / Q000633:toxicity*; D000821:Animal Feed; D000818:Animals; D017756:Aquaculture / Q000379:methods*; D001156:Artemia; D001205:Ascorbic Acid / Q000008:administration & dosage; D015415:Biomarkers / Q000032:analysis; D004032:Diet; D005080:Exercise Test / Q000379:methods; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005240:Feasibility Studies; D007814:Larva / Q000737:chemistry / Q000254:growth & development*; D050356:Lipid Metabolism; D033541:Palaemonidae / Q000254:growth & development*; D011786:Quality Control; D015996:Survival Rate
chemical_list: D015415:Biomarkers; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D000641:Ammonia; D001205:Ascorbic Acid