Zn²⁺ Acute For Juveniles Of Macrobrachium Poisoning Effect

Water temperature 27.4 ± 1.3 ?, pH7.1 ± 0.1 under conditions to body length is 33.23 ± 1.66 mm, weighing 0.7893 ± 0.1518 g of Macrobrachium juveniles as experimental animals, hydrostatic indigestion method [1], launched Zn²⁺ 96 h acute toxicity of Macrobrachium juveniles, and as a basis to calculate the median lethal concentration of Zn²⁺ on Macrobrachium juveniles [2] and experience safe concentrations [3]. To experience safe concentration as the basis, regrouping determined Zn²⁺ at different concentration levels of quality Macrobrachium juveniles oxygen consumption rate [4], suffocation point [5] and ammonia excretion rate [6], and different concentrations of Zn²⁺ Stress Macrobrachium juveniles antioxidant enzymes [7] dynamic testing, to determine the actual security Zn²⁺ concentration Macrobrachium juveniles.By Zn²⁺ on Macrobrachium juveniles pre-acute toxicity test results showed that:?1? mortality Macrobrachium juveniles varies Zn²⁺ concentration increases.?2? when the Zn²⁺ concentration higher than 1.200 mg / L, after 96 h, individual experiments were dead, that is, Macrobrachium juveniles under Zn²⁺ Stress, the lower the concentration of all died after 96 h is 1.200 mg / L.In the pre-obtained experimental 96 h Zn²⁺ Stress died concentration limit is based on re-set different Zn²⁺ concentration constituencies measured nipponense juveniles at different Zn²⁺ concentration, after 24 h, 48 h, 72 h, 96 h mortality to death rate between 0 and 100%. By Zn²⁺ acute toxicity of Macrobrachium juveniles, results showed that:?1? nipponense juvenile survival, Activities and water Zn²⁺ concentration, the mortality test object with increasing concentrations of Zn²⁺ increases.?2? Zn²⁺ on Macrobrachium juveniles gill tissue with obvious erosion of the role of gill color L value with Zn²⁺ concentration increases, a, b values are not significant changes occur that Zn²⁺ on nipponense juveniles acute respiratory physiology and its lethal effect is closely related to metabolic disruption, as the gills of Macrobrachium juveniles main respiratory organs, Zn²⁺ attack is an important target organ toxicity.?3? Zn²⁺ on Macrobrachium juveniles have time to attack drug additive effects [8], under the same conditions Zn²⁺ concentration, nipponense juvenile mortality of 96h?72h?48h?24h.?4? by 96hZn²⁺ acute attack drug, experiment, calculated Zn²⁺ on Macrobrachium juveniles 24, 48, 72, median lethal concentration 96 h in the order of 1.493 mg / L, 0.844 mg / L, 0.643 mg / L and 0.464 mg / L, its experience safe concentrations of 0.149 mg / L, 0.084 mg / L, 0.064 mg / L, 0.046 mg / L.In the acute toxicity test results calculated Zn²⁺ experience safe concentration of Macrobrachium juveniles based, carried out Zn²⁺ on Macrobrachium juveniles breathing oxygen consumption rate, suffocation point and ammonia excretion rate test results showed that:?1? Macrobrachium juveniles having a circadian rhythm of breathing, under normal circumstances, the oxygen consumption rate showed all night> day> day average, which with its nocturnal habits of biological relevance.?2? Zn²⁺ concentration of less than 0.046 mg / L constituency, respiratory rate and oxygen consumption is no different from the control group, but higher than 0.046 mg / L of the group, its oxygen consumption rate with increasing concentration significantly improved.?3? the oxygen content of suffocation point with Zn²⁺ concentration is increased gradually from the maintenance of a stable, slowly increasing to a rapid increase in the transition, which 0.064 mg / L is a rapid increase in the oxygen content of their suffocation point critical point.?4? nipponense juvenile row ammonia also have circadian rhythm, and Zn²⁺ concentration 0.046 mg / L constituency appears critical concentration of a significant change in its discharge of ammonia.?5? nipponense juveniles in Zn2 after concentrations higher than 0.046 mg / L, which increased significantly + protein metabolism.In Zn2 + on Macrobrachium juveniles experience safe concentration based, carried out Zn²⁺ on nipponense juvenile gills hepatopancreas CAT, SOD enzyme activities of experimental results showed that:?1? in the Zn²⁺ low concentration range, nipponense juvenile gills hepatopancreas CAT, SOD enzyme activity were not significantly different.?2? In the Zn²⁺ concentrations higher than 0.046 mg / L of the group, its gill tissue SOD enzyme activity increases with concentration, but concentration 0.100 mg / L group which SOD enzyme activity compared with the previous group is low.?3? In the Zn²⁺ concentrations higher than 0.046 mg / L of the group, its gills CAT enzyme activity increases with concentration, but concentration 0.100 mg / L group at 96 h after its CAT enzyme activity compared with the previous low group.?4? in the Zn²⁺ concentrations higher than 0.046 mg / L constituency, liver pancreas SOD enzyme activity increases with concentration, but concentration 0.100 mg / L group which SOD enzyme activity compared with the previous group is low.?5? In the Zn²⁺ concentrations higher than 0.046 mg / L constituency, hepatopancreas CAT enzyme activity increases with the concentration.Analysis of results by color changes of the L value, oxygen consumption rate, suffocation point, ammonia excretion rate, and other activities of antioxidant enzymes, suggesting that Zn²⁺ on Macrobrachium juveniles experience safe concentration concentration 0.046 mg / L is also the actual security concentration.