title: [Acute toxicity of ammonia in the production process of postlarvae of Penaeus paulensis Pérez-Farfante, 1967].
abstract: Larval shrimp Penaeus paulensis showed a tendency to decrease in ammonia tolerance as the larva metamorphosed from nauplius to postlarvae stage. The 24-h LC50 were 4.04, 1.70, 2.72, and 1.42 mg/l NH3-N on nauplii, zoea, mysis and postlarvae, respectively. The zoea stage and the initial postlarvae substages were very susceptible to ammonia. The 96-h LC50 values on zoea and postlarvae were 0.69 mg/l and 0.32 mg/l, against 0.80 mg/l NH3-N on mysis. The eggs of Penaeus paulensis were very affected by ammonia, which provoked a progressive decrease in the hatching rate and induced morphological deformities in hatched nauplii. A "safe level" of ammonia was estimated at 0.032 mg/l NH3-N on the basis of 24-h LC50 for eggs.
authors.affiliation: Laboratório de Carcinocultura, Centro de Biologia Marinha, UFPR, Curitiba, PR.
authors.forename: A
authors.initials: A
authors.lastname: Ostrensky
authors.forename: M A
authors.initials: MA
authors.lastname: Marchiori
authors.forename: L H
authors.initials: LH
authors.lastname: Poersch
mesh_terms: D000641:Ammonia / Q000633:toxicity*; D000818:Animals; D001938:Brazil; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000187:drug effects; D033561:Penaeidae / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
chemical_list: D000641:Ammonia
vernacular_title: Toxicidade aguda da amônia no processo produtivo de pós-larvas de Penaeus paulensis Pérez-Farfante, 1967.