Effects of copper at sublethal concentrations on growth and biochemical parameters in rainbow trout (Oncorhynchus mykiss)

Abstract

The effects of sublethal concentrations of heavy metals on fish are not well known. Copper (Cu), as one of heavy metals and an environmental stressor, may alter many physiological processes like growth and serum parameters in fish. The main objective of this study was to determine the effects of copper at sublethal concentrations (10 and 30 µg/L) on growth and serum biochemical parameters including enzymes, i.e., alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), glucose, triglyceride, cholesterol, and total protein (TP) in rainbow trout (Oncorhynchus mykiss). Trout were exposed to copper, and at intervals of 1, 15, and 30 days, selected parameters were evaluated. Condition factor (CF), specific growth rate (SGR) and body weight gain (BWG) consistently decreased, while food conversion ratio (FCR) increased at the end of experiment. Glucose, AST, and ALT were elevated, whereas triglyceride and cholesterol decreased in trout exposed to both Cu concentrations (Cu10 and Cu30) at day 15 and then returned to levels comparable to control fish. TP and ALP increased linearly by time and Cu10 and 30. This investigation suggests that growth and serum biochemical parameters could be used as important and sensitive biomarkers in ecotoxicological studies concerning the effects of metal contamination and fish health.

Biochemical, haematological and oxidative stress responses of common carp (Cyprinus carpio L.) after sub-chronic exposure to copper

“…Reduced insulin secretion, causing hyperglycaemia, was also described in fish after longterm exposure to copper (Van Vuren et al 1994;Moon 2001). An increase in plasma glucose levels was documented by several authors in similar studies after the chronic exposure of various fish species to low copper concentrations (Gill et al 1992;Heydarnejad et al 2013;Pretto et al 2014).…”

Legacy effects on sediments in river corridors

“…Wetzel et al (2013) attribute absence of pollution-sensitive invertebrate and fish species in the Elbe River estuary, for example, to presence of trace elements from the city of Hamburg in estuarine sediments. Heydarnejad et al (2013) document the effects of sublethal concentrations of copper on rainbow trout (Oncorhynchus mykiss), which experience decreased growth rates. In many cases, the long-term health effects of sublethal concentrations of contaminants remain unknown, especially in humans, but these contaminants can be very effectively transmitted to people who eat river fish (e.g., Akagi et al, 1995;Barbosa et al, 1997).…”

Anaemia and plasma lipid profile in common carp (Cyprinus carpio) exposed to ambient copper sulphate and nano-scale copper oxide

“…Copper was also shown to affect plasma lipid profile in rat (Galhardi, Diniz, Faine, Rodrigues, Burneiko, Ribas & Novelli ). In fish, only Oncorhynchus mykiss was studied in this case, showing that exposure to water‐soluble copper salts altered plasma cholesterol and triglyceride levels, although the data were contradictory (Munoz, Carballo & Tarazona ; Carballo, Munoz, Cuellar & Tarazona ; Heydarnejad, Khosravian‐hemami, Nematollahi & Rahnama ). However, there are no studies on the effects of excess copper (soluble and nanoparticle) on fish plasma lipoprotein levels, but copper was found to affect hepatic lipase and lipoprotein lipase activities, which are enzymes involved in lipoprotein metabolism (Liu, Luo, Xiong, Liu, Zhao, Hu & Lv ).…”