Tissue-specific Cu bioaccumulation patterns and differences in sensitivity to waterborne Cu in three freshwater fish: rainbow trout ( Oncorhynchus mykiss), common carp ( Cyprinus carpio), and gibel carp ( Carassius auratus gibelio)

Hormonal and ion regulatory response in three freshwater fish species following waterborne copper exposure

Differential metallothionein induction patterns in three freshwater fish during sublethal copper exposure

Exposure to waterborne copper reveals differences in oxidative stress response in three freshwater fish species

Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

Sublethal copper exposure induces respiratory stress in common and gibel carp but not in rainbow trout

Specific anti-SVCV antibodies in hybrids of common carp (Cyprinus carpio) and gibel carp (Carassius gibelio) reflect heterosis advantage and genetic breakdown

The aim of the study was to investigate the serum and tissue disposition of enrofloxacin and its active metabolite ciprofloxacin in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio) after a single oral administration at a dose of 10 mg kg–1. Concentrations of enrofloxacin in the serum of rainbow trout showed high variability with two peaks at the third and 24th hour after administration. The highest concentrations were found in the liver. The curves of liver levels showed similar changes to the respective serum samples. In the muscles, enrofloxacin concentrations were also higher compared with the respective serum samples. Ciprofloxacin concentrations were lower and showed smaller variations in all investigated tissues. The serum and tissue concentrations of enrofloxacin and ciprofloxacin in common carp showed two peaks, with the first Cmax at the third hour after drug administration as in rainbow trout. Concentrations of both investigated substances were higher in the liver than in the serum. The differences in common carp were less pronounced in comparison with rainbow trout. Relatively high levels of both substances were found in the muscles. Seven days after treatment enrofloxacin concentrations in the serum and tissues were within the therapeutic levels for most of the sensitive microorganisms in trout. Lower concentrations of its metabolite ciprofloxacin were found in the investigated tissues at the last sampling point. Lower levels of both substances were found in carp.

Swimming performance and energy metabolism of rainbow trout, common carp and gibel carp respond differently to sublethal copper exposure

Assessment of seminal oxidative stress indicators is emerging as a valuable prognostic tool in assisted reproductive technology. We investigated levels of oxidative stress caused by reactive oxygen species (ROS) and the antioxidant enzyme defence system comprising superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPx) in seminal plasma (SP) of common carp Cyprinus carpio and rainbow trout Oncorhynchus mykiss over the course of the spawning season. Oxidation was determined in lipids and proteins by assessing thiobarbituric acid reactive species (TBARS) and the 2,4-dinitrophenylhydrazine carbonyl groups, respectively. Levels of SOD were assessed by the autoxidation of pyrogallol. Determination of GR and GPx was based on the rate of NADPH oxidation. We observed clear alterations in lipids and proteins over the course of the spawning season in both species. The highest levels of TBARS and CP were recorded late in the season. SOD was not significantly altered in either species. The activity of GR was higher in carp SP late in spawning compared to other times (P < 0.05), while in rainbow trout, GR significantly increased (24.13 ± 2.8 mU/mg protein) in mid-season. A significantly lower GPx activity (9.18 ± 1.32 mU/mg protein) was found in rainbow trout SP early in the spawning season, but no significant differences in GPx were observed over the course of the season in carp. These results provide further understanding of the role of fish SP antioxidants and present new data on the oxidant and antioxidant balance in SP during the spawning season that may be of value in the development of methods for artificial reproduction of teleost species.

Fisheries managers have a growing interest in the use of carbon dioxide (CO2) as a tool for controlling invasive fishes. However, limited published data exist on susceptibility of many commonly encountered species to elevated CO2 concentrations. Our objective was to estimate the 24-h 50% lethal concentration (LC50) and 95% lethal concentration (LC95) of CO2 for four fishes (Rainbow Trout Oncorhynchus mykiss, Common Carp Cyprinus carpio, Channel Catfish Ictalurus punctatus, and Westslope Cutthroat Trout Oncorhynchus clarkii lewisi). In the laboratory, we exposed juvenile fish to a range of CO2 concentrations for 24 h in unpressurized, flow-through tanks. We developed a Bayesian hierarchical model to estimate the dose-response relationship for each fish species with associated uncertainty, and estimated 24-h LC50 and LC95 values based on laboratory trials for each species. The minimum concentration inducing mortality differed among cold water–adapted species and warm water–adapted species groups: 150 mg CO2/L for Westslope Cutthroat Trout and Rainbow Trout and 225 mg CO2/L for Common Carp and Channel Catfish. We observed complete mortality at 275 mg CO2/L (38,672 microatmospheres [μatm]), 225 mg CO2/L (30,711 μatm), and 495 mg CO2/L (65,708 μatm [Common Carp]; 77,213 μatm [Channel Catfish]) for Westslope Cutthroat Trout, Rainbow Trout, and both Common Carp and Channel Catfish, respectively. There was evidence of a statistical difference between the 24-h LC95 values of Westslope Cutthroat Trout and Rainbow Trout (245.0 [222.2–272.2] and 190.6 [177.2–207.8] mg CO2/L, respectively). Additionally, these values were almost half the estimated 24-h LC95 values for Common Carp and Channel Catfish (422.5 [374.7–474.5] and 434.2 [377.2–492.2] mg CO2/L, respectively). Although the experimental findings show strong relationships between increased CO2 concentration and higher mortality, additional work is required to assess the efficacy and feasibility of a CO2 application in a field setting.

High trophic similarity between non-native common carp and gibel carp in Turkish freshwaters: Implications for management

Abstract. Hematological assessment is an important tool in evaluating the fish health status. This tool corroborated with biochemical, parasitological and bacterial examinations aids the researchers in monitoring fish welfare status. For relevant blood samples using the right harvesting methodology with the right anticoagulant is imperative. This study presents a comparison between two different anticoagulants like Li-Heparin and ethylenediaminetetraacetic acid (EDTA) in common carp ( Cyprinus carpio ) and rainbow trout ( Oncorhynchus mykiss ). Two common carps and two rainbow trouts were submitted for blood harvesting using Li-Heparin and EDTA containers. Blood smears were prepared using a Romanowsky staining procedure and examined via light microscopy. The results of the study revealed significant in vitro hemolysis and red blood cell morphologic alterations in the common carp blood samples when harvested on EDTA in contrast with the Li-Heparin anticoagulant. The white blood cells showed no significant changes induced by neither of the two anticoagulants. No significant anticoagulant induced cell morphological alterations were noticed in the rainbow trout. It is concluded that EDTA is not the appropriate anticoagulant for hematologic evaluation in common carp.

During a 3-month period from June to the end of August 2016, ~5% mortalities were observed in a farm with rainbow trout (Oncorhynchus mykiss Walbaum) and one farm of common carp (Cyprinus carpio L.) in Bulgaria. The disease was manifested by gill ulcers/rot, asphyxiation and bloody ascites. Aeromonas hydrophila was isolated from the internal organs of all the diseased fish. Bacillus mycoides or B.pseudomycoides were recovered from the gill lesions on diseased carp and rainbow trout, respectively, with identification achieved by conventional phenotyping and by sequencing of the 16S rRNA gene. In vivo experiments confirmed that all three organisms were pathogenic to rainbow trout.

Accumulation of 20 elements in great cormorant (Phalacrocorax carbo) and its main prey, common carp (Cyprinus carpio) and Prussian carp (Carassius gibelio)

The efficiency of enzymatic conversion of glucose into glucose-6-phosphate in fish fed carbohydrates is still a matter of debate. This study reports the first ever identification of hexokinase-family members at a molecular level in fish. The deduced amino acid sequences of six cDNA clones allowed their assignement either to hexokinase IV (glucokinase) for rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gilthead seabream (Sparus aurata) or to hexokinase I/II for the common carp (two clones) and the gilthead seabream, based on their similarities to known members of the HK family. The evolutionary relationships among these sequences were investigated by phylogenetic analysis. These hexokinase sequences constitute potential molecular tools for analysis of interspecific differences in dietary carbohydrate utilization in fish.