Efeito da amônia sobre a fertilização artificial de ovócitos e no desenvolvimento inicial do jundiá cinza (Rhamdia quelen; Siluriformes, Heptapteridae)

Abstract

de taxa de fertilização, unidade térmica acumulada para início e término da eclosão, taxa de eclosão, desenvolvimento embrionário e percentual de larvas normais. Os resultados foram submetidos a análise de variância e a análise de regressão a um nível de 5% de probabilidade. Os níveis de amônia presentes na água não interferiram sobre os parâmetros avaliados (p>0,05), exceto quanto ao desenvolvimento embrionário inicial, onde os embriões expostos aos maiores níveis de contaminação por amônia apresentaram maiores (p<0,05) taxas de fechamento do blastóporo. De modo geral, a presença de até 0,84mg de amônia total.L de água -1 acelera o desenvolvimento inicial embrionário mas não interferem nas taxas de fertilização e eclosão. Palavras-chave: Amônia, embrião, larvas, peixe, poluente AbstractThe aim study it had as objective to evaluate the effect of different ammonia levels, on the parameters of sperm motility, the artificial fertilization and the early development of jundia (Rhamdia quelen; Siluriformes, Heptapteridae). The semen was activated using the dilution of 1:70 (semen:water) and evaluated by the CASA method. It was considered as treatment water contending 0,06; 0,28; 0,50; 0,77

Tolerance of piava juveniles to different ammonia concentrations

“…The observed behaviors are consistent with previous descriptions of the damaging effects on the central nervous system that may be caused by acute NH 3 toxicity (RANDALL; TSUI, 2002;WALSH et al, 2007). Exposure to sub-lethal concentrations of NH 3 halts the metabolism of amino acids and mitochondria in the brain (WALSH et al, 2007). Similar results were described for sea bass (Dicentrarchus labrax), sea bream (Sparus aurata), and turbot (Scophthalmus maximus) juveniles that were exposed to 6.43, 4.87 and 5.70 mg L -1 NH 3 , respectively, for 96 h (RUYET et al, 1995), although these species could adopt a different physiological pattern of the species of this study, because they are adapted to colder waters.…”

“…The observed behaviors are consistent with previous descriptions of the damaging effects on the central nervous system that may be caused by acute NH 3 toxicity (RANDALL; TSUI, 2002;WALSH et al, 2007). Exposure to sub-lethal concentrations of NH 3 halts the metabolism of amino acids and mitochondria in the brain (WALSH et al, 2007).…”

“…In this experiment, piavas that were exposed to the higher concentrations of NH 3 demonstrated responses that are typical of fish that are under short-term exposure to ammonia, including loss of equilibrium, erratic swimming, and death (RANDALL; TSUI, 2002;WALSH et al, 2007). The observed behaviors are consistent with previous descriptions of the damaging effects on the central nervous system that may be caused by acute NH 3 toxicity (RANDALL; TSUI, 2002;WALSH et al, 2007).…”

“…These consequences most likely occur because the elevated levels of NH 4 + displace K + , which increases neuronal firing rate (ERDOGAN et al, 2005;WALSH et al, 2007). Chronic or sublethal exposure to NH 3 can also cause degeneration of tissues in the gills (MIRON et al, 2008).…”

“…Chronic or sublethal exposure to NH 3 can also cause degeneration of tissues in the gills (MIRON et al, 2008). Sub-lethal ammonia concentrations decrease the growth rate of fish (MIRON et al, 2011;FERREIRA et al, 2013), interfering in the artificial fertilization (VIDAL et al, 2013) and may cause several physiological and histological changes (WRIGHT;WOOD, 2012;LIEW et al, 2013). For these reasons, toxicity of ammonia to fish has been intensively investigated in numerous fish species (BENLÍ;KÖKSAL, 2005;ERDOGAN et al, 2005;MIRON et al, 2008;LIEW et al, 2013;FERREIRA et al, 2013).…”