Acute effects of ammonia exposure on the plasma and haematological parameters and histological structure of the juvenile blunt snout bream, Megalobrama amblycephala , and post-exposure recovery

Abstract

In this study, we investigated the toxic effects of ammonia-N on the plasma and haematological parameters and histological structure of blunt snout bream (Megalobrama amblycephala) juveniles. The fish (initial weight, 14.79 AE 0.01 g) were randomly sorted into six tanks (200 L), and each tank was stocked with 40 fish for culture. The juveniles were exposed to two ammonia-N levels-0 mg/L (control group) and 25 mg/L (experimental group)-and sampled at 0, 6, 12, 24, 48 and 72 hr, and then they underwent 96 hr of post-exposure recovery. The results showed that ammonia-N had significant effects on the plasma and haematological parameters. The treatment group showed increased cortisol, plasma ammonia and haematocrit levels and white blood cell count with increasing exposure time, up to 24 hr, and then the levels and count decreased. A significantly higher plasma glucose level was observed in the treatment group at 12 hr. After 96 hr of post-exposure recovery, all parameter levels decreased to the control levels. The fish displayed histopathological alterations in the gills, liver and kidney. The results indicate that the severity of the lesions clearly differed among the organs, with the liver showing the most extensive damage, followed by the gills and kidney. Adverse effects to physiological indicators and histological structure increased with increasing exposure time before 24 hr. The fish showed self-regulation; however, the histological structure could not recover fully, the gill tissue showed irreversible changes and the kidney tissue exhibited the worst recovery ability.

Toxic Effects on Bioaccumulation, Hematological Parameters, Oxidative Stress, Immune Responses and Tissue Structure in Fish Exposed to Ammonia Nitrogen: A Review

“…In the present studies, the histopathological effects of acute ammonia exposure on gills were chloride cell proliferation, hyperemia, epithelial elevation, secondary laminae convolution, laminae fusion, and secondary laminae shortening [ 117 , 118 ]. Zhang et al found histopathological changes in gill tissues of all Megalobrama amblycephala exposed to different concentrations of ammonia by pathological histological examination, which revealed cytoplasmic vacuolation, damaged mitochondria, increased heterochromatin and significant epithelial cell detachment in gill tissue [ 119 ]. Ricardo et al found that ammonia exposed maroon clownfish gills exhibited lamellar deformation, lamellar shortening, mucosal cell hyperplasia and hypertrophy [ 111 ].…”

“…Benli et al observed cloudy swelling and hydropic degenerations on the liver in Oreochromis niloticus L. when they were subjected to sublethal concentrations of ammonia nitrogen [ 7 ]. Zhang et al also observed large fields of nuclear hypertrophy in the liver, which indicated that the liver of juvenile blunt snout bream could not fully recover after 96 h post-exposure [ 119 ]. Therefore, ammonia exposure can cause structural disruptions in fish livers and make it difficult to recover.…”

“…Ravindrababu et al observed vacuolation and degeneration of renal tubular epithelial cells in the kidneys of Oreochromis mossambicus after 14 days of exposure to ammonia nitrogen, and the intensity of damage to renal tubules was more clearly observed in exposed fish at 14 days than at 7 days [ 126 ]. Zhang et al observed renal tubular dilatation and severe histopathological damage (vacuolation and degeneration of the renal tubular epithelium) in the kidneys of juvenile blunt snout bream after 24 h of exposure [ 119 ]. The kidneys of Nile tilapia ( Oreochromis niloticus L.) exposed to ammonia nitrogen exhibited pathological features such as glomerulonephritis and congestion [ 7 ].…”

Intra-variability of some biochemical parameters and serum electrolytes in rainbow trout (Walbaum, 1792) bred using a flow-through system

“…Research has shown that the immune system may be affected by excessive ammonia nitrogen in the environment may [37]. Furthermore, damage may occur to the liver, gill, kidney and other fish organs [38].…”

Evaluating the effect of acute ammonia toxicity in a freshwater ecological environment on the growth and hematological functioning of Clarias gariepinus

“…Fishes are vulnerable to toxicity, especially when exposed to several nitrogenous compounds such as ammonia in their environments. A lot of work have been done on acute and chronic ammonia toxicities in many marine fish, especially scaly species, such as Megalobrama amblycephala (Zhang et al 2017), Oreochromis niloticus (Benli et al 2008), Salmo salar (Kolarevic et al 2012) and Premnas biaculeatus (Rodrigues et al 2014), but little research has been attempted on scaleless fish. In addition, C. gariepinus is a scaleless freshwater fish that may be more susceptible to the effects of toxic chemicals than fish with scales.…”