Lethal concentration (CL50) of un-ionized ammonia for pejerrey larvae in acute exposure

Abstract

Ammonia results from decomposition of effluents organic matter, e.g. feed wastes and fish faeces. Its un-ionized form can be toxic because diffuses easily through fish respiratory membranes, damaging gill epithelium and impairing gas exchanges. The objective of this work was determining the 96-hour CL 50 of un-ionized ammonia for newly hatched pejerrey Odontesthes bonariensis larvae. Trials were set up completely randomized design, with three different concentration of un-ionized ammonia (0.57, 0.94, and 1.45 mg L -1 NH 3 -N) and a control treatment (n = 3). Experimental units were 20-L, aerated aquaria stocked with 20 larvae (average weight 3.9 mg). Pejerrey larvae exposed to un-ionized ammonia during 96 hours present 50% mortality at 0.71 mg L -1 NH 3 -N. Key words: pejerrey, Odontesthes bonariensis, toxicity, nitrogen, larvae CONCENTRAÇÃO LETAL (CL 50 ) DE AMÔNIA NÃO IONIZADA PARA LARVAS DE PEIXE-REI EM EXPOSIÇÃO AGUDARESUMO: A amônia é originada da decomposição da matéria orgânica dos efluentes, como restos de rações e fezes dos peixes. Sua forma não ionizada pode atingir concentrações tóxicas, pois difunde-se facilmente através das membranas respiratórias causando danos ao epitélio branquial, dificultando as trocas gasosas entre o animal e a água. O objetivo deste trabalho foi determinar a CL 50 para 96 horas de exposição a amônia não ionizada de larvas recém-eclodidas de peixe-rei Odontesthes bonariensis. O experimento foi conduzido em delineamento completamente casualizado, usando três diferentes concentrações de amônia não ionizada (0,57, 0,94 e 1,45 mg L -1 NH 3 -N) e um controle (n = 3). As unidades experimentais constaram de aquários de 20 litros, aerados, povoados com 20 larvas (peso médio 3,9 mg). Larvas de peixe-rei expostas por 96 horas à amônia não ionizada apresentam mortalidade de 50% na concentração de 0,71 mg L -1 NH 3 -N.

Acute toxicity of ammonia on juvenile cobia (Rachycentron canadum, Linnaeus, 1766) according to the salinity

“…The toxicity of ammonia-N for fish juveniles has been studied by several authors (Frances et al 2000;Hargreaves and Kucuk 2001;Wang and Walsh 2000;Wicks and Randall 2002;Sampaio et al 2002;Cavero et al 2004;Lamarié et al 2004;Piedras et al 2006). The results of this study confirm that the ammonia-N and NH 3 are toxic to cobia, an ecologically and economically important fish in coastal waters.…”

“…The lethal effects of ammonia in fish juveniles have been studied in Bidyanus bidyanus (Frances et al 2000), Arapaiama gigas (Cavero et al 2004), Morone saxatilis (Hargreaves and Kucuk 2001), Dicentrarchus labrax (Lamarié et al 2004), Opsanus tau (Wang and Walsh 2000), Mugil platanus (Sampaio et al 2002), Oncorhynchus kisutch (Wicks and Randall 2002) and Odontesthes bonariensis (Piedras et al 2006). However, little information is available on the lethal effect of ammonia at different salinity levels in Rachycentron canadum (Rodrigues et al 2007).…”

Acute toxicity of ammonia in Pacu fish (Piaractus mesopotamicus, Holmberg, 1887) at different temperatures levels

“…The lethal effects of ammonia in juvenile fish have been studied in Oncorhynchus mykiss (Arthur, Corlis, Allen & Hedtke ), Ictalurus punctatus (EPA – United States Environmental Protection Agency ), Dicentrarchus labrax (Lamarie, Dosdat, Cove's, Dutto, Gasset & Ruyet ), Opsanus tau (Wang & Walsh ), Cyprinus carpio (Peyghan & Azary Takami ), O. kisutch (Wicks & Randall ) and Odontesthes bonariensis (Piedras, Pouey, Moraes & Cardoso ), Hyphessobrycon callistus (Danato & Barbieri ), Rachycentron canadum (Barbieri & Doi ). However, information about the lethal effect of ammonia at different temperatures levels in P. mesopotamicus is rare.…”

Acute toxicity of ammonia and nitrite to different ages of Pacific cod (Gadus macrocephalus) larvae

“…Miller et al [36] found that the 96-h LC 50 for UIAN in larval inland silversides (Menidia beryllina) was 0.97 mg L −1 at 25 °C, a salinity of 31, and pH 7. Piedras et al [37] stated that the 96-h LC 50 for UIAN in newly hatched pejerrey (Odontesthes bonariensis) larvae (average weight 3.9 mg) was 0.71 mg L −1…”