Comparative studies of codon usage profile of Anisakis simplex (Nematoda) and Carassius gibelio (Prussian carp)

Aim: The aim of the present study was to understand the molecular relationship between nematode (parasite) and fish (host) through codon usage bias (CUB) analysis. Methodology: The Codon usage bias analysis has been performed in fish Carassius gibelio (Prussian carp) and nematode fish parasite Anisakis simplex. The complete coding sequences (CDS) of C. gibelio (Prussian carp) and A. simplex (Nematode) were retrieved from National Center for Biotechnology Information and followed to that we have performed bioinformatics analysis to understand the codon usage pattern between host and parasite. Results: Different CUB indices like Relative synonymous codon usage (RSCU), Effective number of codons (ENC), Codon adaptation index (CAI) and Codon bias index (CBI) revealed a similar pattern in the codon usage in C. gibelio and A. simplex. In addition, inclusive analysis using different plots (ENC, parity, neutrality) had shown the influence of both the evolutionary forces i.e mutational and translational selection on codon usage pattern. This describes the role of evolutionary forces in determining the conserved genome to establish species-specific function-level differences for efficient survival. Interpretation: The present study elucidated the association between Carassiusgibelio (host) and Anisakis simplex (parasite) based on the similar pattern of codon usage bias between both the species.

Bioaccumulation of heavy metals in the water, sediment and the tissues of Carassius gibelio (Bloch, 1782) from Eber Lake

In this research, in order to observe the seasonal change between April 2014 and February 2015, heavy metal contents in the water, sediment and the Carassius gibelio (Bloch, 1782) tissues (muscle, gill and liver) growing in Eber Lake were determined. The obtained results showed that trace elements were founded in water, sediment and fish tissues. Among the average annual concentrations of water samples, the highest concentration was found for Mn (0.1584 mg/L) element and the lowest concentration was found for Pb element in the spring season. the maximum Average annual concentration was calculated for Mn (0.1584 mg/L, Spring) and the minimum was determined for Pb in water. In the sediment, Fe (16245.84 mg/kg, Spring) was found to be maximum and Co was the minimum. In fish, the highest concentrations were found in liver (Mo, Ni, Pb, Co, Cu, Fe), while the lowest concentrations were found in gill (Mn, Zn) and muscle (Cd, Cr, Se) tissues While the highest heavy metal concentrations were observed in the sediment, the minimum was found in the fish tissues (the ranking was the following; liver, gill and muscle). It was concluded that the heavy metal levels measured in the Lake Eber have no risk to the environment and to the public health.

Helminths and helminth communities of Carassius gibelio (Bloch, 1782) from the Panicheri Reservoir, Aegean Water Basin, Bulgaria

Ecologoparasitological research was done based on the helminths and helminth communities of the Prussian carp (Carassius gibelio (Bloch, 1782)) from the freshwater ecosystem of the Panicheri Reservoir, Aegean Water Basin, Bulgaria. As a result of the examined nine specimens of the Prussian carp, two species of helminths were found: Ligula intestinalis (Linnaeus, 1758), larvae and Pomphorhynchus laevis (Müller, 1776). The dominant structure of the helminth communities was determined. The Panicheri Reservoir is a new habitat in Bulgaria of P. laevis and L. intestinalis from C. gibelio. C. gibelio is a new host record for L. intestinalis in Bulgaria. The two helminth species are core species for the helminth communities of the examined species of the freshwater fish. P. laevis was distinguished with higher prevalence and mean intensity (P%=33.34; MI=1.34) than L. intestinalis (P%=22.23; MI=1.0). The circulatory pathways of the helminth flow were traced.

Potentially Toxic Elements in Invasive Fish Species Prussian Carp (Carassius Gibelio) from Different Freshwater Ecosystems and Human Exposure Assessment

Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, and Zn were detected in the muscle and gills of Prussian carp from three different freshwater ecosystems: isolated ponds and the South Morava River in Serbia, and Kopačko Lake in complex wetland ecosystem of the Kopački Rit Nature Reserve in Croatia. The main goals of the paper were to assess the concentrations of potentially toxic elements (PTEs) in the muscle and gills of Prussian carp (Carassius gibelio), to examine whether abiotic factors from three different freshwater ecosystems affect the accumulation of PTEs in fish tissues and to estimate the human health risk resulting from fish consumption. There were only six concentrations of PTEs in the gill tissue (Cr, Hg, Mn, Pb, Sn, and Zn) that were not significantly different among the different freshwater ecosystems. In the muscles, the differences were much less visible. Kopačko Lake distinguished with the highest values of metal pollution index (MPI) for muscles (0.24) and isolated ponds with the highest values of MPI for gills (0.8). The redundancy analysis (RDA) showed that concentrations of Al, Mn, Zn, Cu, and Fe in the gill tissue were significantly correlated with the environmental variables. In contrast, the RDA based on element concentrations in the fish muscles indicated no significant relationship with the environment. Isolated ponds, with no inflow of freshwater, stand out as the most polluted, followed by Kopačko Lake with occasional floods. Flowing freshwater ecosystem South Morava River can be single out as at least polluted with PTEs. The target hazard quotients (THQ) and hazard index (HI) suggested there were no significant noncarcinogenic health risks. The target carcinogenic risk factor (TR) for As and Pb confirmed there were no cancer risks related to human fish consumption. Since the elevated concentrations of toxic Cd and As in Prussian carp were estimated, an early warning should be assumed, especially for fishing activities in these areas.