Effects of In-Situ Cadmium Exposure on Morphometric Indices of Anabas testudineus

Anthropogenic activities have greatly affected water resources on a global scale where the world is experiencing water quality and resources issues. Heavy metal is a crucial group of pollutants that is toxic to the environment even at low concentrations due to its bioaccumulation and biomagnification capabilities in living organisms. The detrimental effects of heavy metals on living organisms are due to their bioaccumulation in the aquatic ecosystem. Cadmium may result in adverse health effects due to its high toxicity. The study is conducted to determine the cadmium exposure effects on the morphometric indices of Anabas testudineus which are the Scaling Coefficient (SC) and Condition Factor (K) of such species. Anabas testudineus is exposed to four different cadmium treatment groups namely the control group, cadmium treatment group of 0.005 mg/L, 0.010 mg/L, and 0.015 mg/L for 16 weeks. The findings of the study have reported inconsistent trends in the values of SC and a decrease in the value of K with increasing cadmium concentration. The trend for the average SC has shown an overall decrease in value while the pattern of the K value is inconsistent in each treatment group with exposure time. Collectively, no significant differences for SC and K of A. testudineus in different treatment groups as well as comparison between treatment groups with time exposure.

Effect of Cadmium on the Developmental Instability of Anabas testudineus through Evaluation of Fluctuating Asymmetry of Eye Diameter

Biomonitoring using fish has been a popular method of assessing the toxic effects of cadmium concentrations of cadmium in water bodies and has led to bioaccumulation in fish contributing to various morphological alterations. Among the known effects of these alterations is developmental instability via fluctuating asymmetry (FA). The utilization of FA data is a simple yet effective method to evaluate the toxic effects of cadmium on the stability of development. This study used climbing perch (Anabas testudieneus) to assess the FA in the diameter of the eye because of low-level cadmium exposure. The left and right sides of the traits were measured once every four weeks for 16 weeks. The average measurements from both sides of the traits were used to calculate the FA value. Results found that the highest mean FA for the diameter of the eye was obtained in the highest treatment group, 0.015 mg/L. The results also indicate that increasing concentrations of cadmium exposure had a statistically significant effect on the FA of eye diameter. There was also a statistically significant interaction between the duration of exposure and treatment groups in FA of the diameter of the eye. The results from the study indicate that prolonged exposure to sub-lethal concentrations of cadmium can cause significant effects on the normal development of eyes in Anabas testudineus. This study can add to the body of research regarding fluctuating asymmetry as a tool to study developmental toxicants and assess other bilateral organs.

Role of Exogenous Reduced Glutathione on Time Dependent ^(203)Hg Distribution in Liver and Kidney of a Freshwater Teleost, Anabas testudineus

Time-dependent tissue distribution of mercury(Hg) was studied in a freshwater perch,Anabas testudineus which revealed that the liver and kidneys are the major sites of Hg reten tion. The role of reduced glutathione (GSH) in the clearance of Hg was also investigated to e valuate the ameliorative effect of this nucleophile. For this purpose, the perch was given GSH 15 min before or after they received 203Hg by injection. The fish were then sacrificed at 24 h and 48 h later. The results clearly indicate that exogenous GSH can significantly reduce Hg retention in both the liver and kidneys, demonstrating a direct role of this nucleophile in the amelioration of Hg-induced toxicity in the early phase of intoxication

Time Dependent Tissue Distribution of ^(203)Hg in the White Rat and Anabas testudineus, a Freshwater Teleost

The distribution of mercury, an environmentally important toxicant, has been evaluated in a time dependent manner in different tissues of white rat and a freshwater teleost, Anabas testudineus. Sampling was performed at 15 min, 2, 6 and 48 h post injection (im) of 203Hg mercuric nitrate. Radioactivity of the 5% tissue homogenate, serum and bile was measured in a Gamma Counter. The rate of 203Hg accumulation is higher in fish immediately after administration which, however, is more or less of equal rate in the later period of observation in both the experimental animals. Partitioning of 203Hg occurs in a species specific manner with higher levels recorded in the brain and gonad of white rat. Spleen, liver and kidney, however, are the major tissues to accumulate mercury in both the species. The present study highlights that kidney is the target site of mercury retention with a higher kidney/liver ratio of mercury.

Aeromonas veronii isolated from climbing perch(Anabas testudineus)suffering from epizootic ulcerative syndrome(EUS)

Motile Aeromonads are responsible for various diseases in fishes that cause significant economic losses in aquaculture.Aeromonas spp.are also frequently isolated from fish suffering from Epizootic Ulcerative Syndrome(EUS).The present study was conducted to isolate and identify A.veronii from Vietnam climbing perch(Anabas testudineus)suffering from EUS,evaluate the pathogenicity of the isolates,and find out antibiogram profile and susceptibility of the isolates to medicinal plant extracts.Vietnam climbing perch(A.testudineus)suffering from EUS was collected from fish farms located at Savar,Dhaka and bacteria were isolated from the external ulcerative lesion,and kidney and liver of the infected fish on nutrient agar plates.Preliminary phenotypic identification of the bacterial isolates was performed following morphological,physiological and biochemical characterization tests.The 16S rRNA gene sequencing was accomplished for further molecular identification of five selected isolates.To evaluate the pathogenicity of the isolates in vivo artificial infection challenge test was conducted through immersion method.Another in vivo pathogenicity test was done at three different temperatures(18◦C,28◦C,and 37◦C)to examine the effects of temperature on the pathogenicity of the isolates.Ten commercial antibiotics were used to find out the antibiogram profile of the isolates.Finally,susceptibility of the isolates was screened against 19 medicinal plants extracts.A total of 38 out of 46 isolates isolated from Vietnam climbing perch(A.testudineus)suffering from EUS were phenotypically identified as Aeromonas sp.Five randomly selected isolates were further confirmed as A.veronii by analyzing the 16S rRNA gene sequence homology.The pathogenicity of the isolates was found moderate to high(41%-80%mortality)in the artificially challenged fish.The highest and lowest mortality was obtained in the fish challenged with the isolates BFKA33 and BFKA12,respectively.The isolates were found resistant to several antibiotics,including amoxicillin,ampicillin,penicillin-G,and vancomycin.Nevertheless,extracts of three medicinal plant(Allium sativum,Syzygium aromaticum,and Tamarindus indica)demonstrated antibacterial activity to the isolates(BFKA12,BFKA15,BFKA18,BFKA29,and BFKA33).

A preliminary survey on parasitic occurrence in indigenous climbing perch,Anabas testudineus(Bloch,1972)from West Bengal state of India

Objective:To describe the parasitic infestations of Anabas testudineus(A.testudineus)collected from three different fish producing districts of West Bengal state in India.Methods:A total number of 75 specimens of A.testudineus were collected from different floodplain areas of West Bengal,India.These specimens were examined for parasites using established techniques after measuring basic morphometric parameters.Results:A total 165 individual of 20 parasites(13 ectoparasites and 7 endoparasites)belonging to 7 phyla were recorded from 64 infected A.testudineus.Among the observed parasites,8 were protozoan including 3 ciliates;2 monogenic trematodes,2 strigeidid trematodes,1 nematode,3 crustaceans,3 myxozoans and 1 echinorhynchus acanthocephalan parasites.The quantitative abundance of parasites were highest in gill(37%)followed by body outer layer(35%)and intestine(28%).District wise quantitative count of parasites in different investigated organ from A.testudineus revealed that North 24 Parganas is highly infected followed by West Midnapore and East Midnapore.The highest prevalence(%)and mean abundance of parasitic occurrence was observed in North 24 Parganas followed by West Midnapore and East Midnapore.The highest mean intensity was found at West Midnapore followed by North 24 Parganas and East Midnapore.Conclusions:Especially West Bengal state of India,inland culture and capture fishery mainly rural based and operated by poor farmers.Developing right kind of interventions and management practice can prevent adverse impact of diseases and assist poor farmers for sustainable production.