Physiological responses of matrinxã (Brycon amazonicus) fed different levels of vitamin C and submitted to air exposure

Abstract

The role of vitamin C on physiological responses of matrinxã (Brycon amazonicus) submitted to air exposure was analyzed. Nine hundred fish (70.15 g) were distributed in fifteen 500 l boxes (60 fish.box -1 ) and fed five rations (treatments): Control (no vitamin C); T100 (100 mg); T200 (200 mg); T400 (400 mg) and T800 (800 mg of vitamin C kg.ration -1 ). Each ration was offered to fish of three boxes during 60 days before the stress challenge that consisted of exposing fish to air for two minutes. Samplings were carried out for 5, 15, 30 and 60 minutes after the air exposure. Blood was collected for glucose, cortisol, total protein, sodium, chloride, hematocrit, hemoglobin determination, and white and red cell count. Liver was removed for hepatosomatic index (HSI) calculation and glycogen determination. Vitamin C did not affect the levels of cortisol, chloride, total protein, hemoglobin, leukocytes, hepatic glycogen or HSI in air exposed fish. Blood glucose levels elevation observed 60 minutes after the challenge did not depend on the levels of vitamin C, nor did the drop in serum sodium levels verified 60 minutes after stressor. In general, hematocrit did not change by effect of vitamin C but it was lower at 15 and 30 minutes after the challenge. The number of erythrocytes decreased in fish after 5 minute sampling in all treatments, especially at 30 and 60 minutes. The air exposure evoked alterations in stress indicators of matrinxã, and the vitamin C did not alter the responses. KEY WORDSBrycon amazonicus, capture, stress, ascorbyl -polyphosphate. de glicose, cortisol, proteína total, sódio, cloreto, hematócrito, hemoglobina, contagem Respostas fisiológicas de matrinxã (Brycon amazonicus) arraçoados com diferentes níveis de vitamina C e submetidos à exposição aérea RESUMO Este trabalho avaliou a participação da vitamina C nos indicadoras de estresse no matrinxã (Brycon amazonicus), durante exposição aérea. Novecentos peixes (70,15g) foram distribuídos em caixas de cimento (500 l) e alimentados com os tratamentos: Controle (sem vitamina C); T100 (100 mg); T200 (200 mg); T400 (400 mg); T800 (800 mg de vitamina C kg.ração -1 ). Cada ração foi fornecida a peixes de três caixas por 60 dias antes da aplicação do estressor, que consistiu em suspender os peixes mantendo-os no ar por dois minutos. Cinco, 15, 30 e 60 minutos depois, os peixes anestesiados foram amostrados. Foi coletado sangue para determinação PALAVRAS -CHAVEBrycon amazonicus, captura, estresse, ascorbil polifosfato.

β-Glucan-induced cortisol levels improve the early immune response in matrinxã ( Brycon amazonicus )

“…The number of circulating erythrocytes increased only after acute infection, suggesting that the response of matrinxã to stress by air exposure did not affect this parameter and it was not modulated by dietary b-glucan. In contrast, previous reports indicated that stress increased the number of circulating erythrocytes in matrinxã after 4 h transport [39] or after 2 min air exposure and sampled after 5 min [68]. The different results can be explained by different stressor intensity, duration, and sampling time.…”

Stress evaluation in dourado females (Salminus brasiliensis) submitted to two different methods of induced spawning

“…There was no difference in total leukocytes when comparing both methods as described in Table 3. According to Abreu and Urbinati (2006), feeding Brycon cephalus breeders with different concentrations of vitamin C submitted to air exposure, and Pimpão (2006), studying Ancistrus multispinis exposed to deltametrin, found similar results. For the most of fishes' species, leukocytosis can be found as soon as a stressor agent is present in attempt to recover from homeostasis disruption, while leukopenia is generally attributed to diseases that affect immunological system (Vosylienė, 1999).…”

“…Data presented in Table 2 demonstrate that there is no statistically difference for hemoglobin concentration, hematocrit and number of red blood cells comparing experimental groups. Similarly, Abreu and Urbinati (2006), for Brycon amazonicus, Martins et al (2004), for Oreochromis niloticus and Pimpão (2006), for Ancistrus multispinis, found no difference in hematocrit in fish under stress conditions. Number of red blood cells and hemoglobin concentration, otherwise, differ from Das and Mukherjee (2003) and Adhikari et al (2004), who demonstrated reduction in these parameters for Labeo rohita exposed to stressor agents.…”

Histopathological changes in surubim Pseudoplatystoma coruscans subjected to high levels of vitamin C

“…In many species, high levels of vitamin C do not produce beneficial results. Verlhac et al (1994) observed an increased phagocytic activity in macrophages and activation of the complement system in trout fed with high doses of vitamin C. Abreu and Urbinati (2006) did not observe a reduction in the effects of the stress from air exposure in matrinxã, Brycon amazonicus, fed with 800 mg of ascorbic acid/kg of diet supplementation. However, Affonso et al (2007) recommended the use of 800 mg of ascorbic acid/kg of diet for some species based on the observation of a high number of leukocytes and plasma protein in fish submitted to this supplementation level.…”