| Throughout the world pesticides are widely employed in agriculture sector in order to elevate crops’ yield with low labour and efforts. Pesticides exposure leads to toxicity in many non-target organisms, fish being one of the most prominent among these. Most of the time acute concentration of these pesticides leads to mortality while sub lethal concentration of these pesticides result in different lethal changes. These changes may be in behaviour of the exposed fish such as change in feeding behaviour, attack or avoiding behaviour and reproductive behaviour, or other types of alterations such as changes in histology (liver, kidneys, gills, muscles, brain, intestine), haematology (RBCs, WBCs or Plasma), anti-oxidant defence system (Glutathione reductase, Peroxidase, Catalase, Superoxide dismutase, Glutathione peroxidase, Glutathione-S-transferase etc.), changes in nutrient profile (Protein, Lipids, Carbohydrates, Moisture content and Ash etc.) and worth of the fish, hormonal or enzymatic alterations, oxygen consumption, and DNA damage or damage at genes level (genotoxicity). Different environmental agencies are working on this aspect and that’s why there are a large number of banned chemicals. Still these chemicals are available in markets. Certain newly synthesized pesticides (insecticides or fungicides etc.) and extensive use of these chemicals are always there to maximize the problem for aquatic organisms especially fish. This article focuses on the same aspect of ecotoxicology and reviews some major induced toxicological aspects of pesticides in fish including behavioural changes, histopathological damages, haematological alterations, biochemical changes, fluctuations in acetylcholinesterase activity, vicissitudes in protein contents, induced genotoxicity, alterations in feeding biology, oxygen consumption and oxygen stress all across the world.

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Ecotoxicology: a review of pesticides induced toxicity in fish.

Pesticide residues with genotoxic potential reach the aquatic environment and constitute a major issue that give rise to concerns at local, regional, national and global scales. Fish serves as an excellent genetic model for the genetic hazard assessment as they are very sensitive to changes in their environment. As there is a close consortium of DNA damage, mutation and induction of various types of genetic disorders, genotoxicity tests like chromosomal aberration test, micronuclei and comet assay are gaining credence and since past few decades many tests have been developed for evaluating genetic alterations in aquatic organisms. These tests rely on the premise that any change to DNA may have enduring and ardent consequences. Thus, the first aim of the genotoxicology is to describe the outcome produced by toxic substances in various test species, but only from the genetic point of view and to draw conclusions that can be extrapolated to man. This review summarizes the genotoxicity tests developed till date and the role of piscine model in genotoxicology. The text also delves the latest knowledge and thinking on these cardinal approaches for the assessment of aquatic environmental health, management and conservation, besides providing useful repository for the researchers especially dealing with aquatic genotoxicity tests. The perspectives for further research on the use of genotoxicology tests were also highlighted.

https://www.longdom.org/open-access/an-introduction-about-genotoxicology-methods-as-tools-for-monitoring-aquatic-ecosystem-present-status-and-future-perspectives-2150-3508-1000158.pdf

An introduction about Genotoxicology Methods as Tools for Monitoring Aquatic Ecosystem: Present status and Future perspectives

Summary In the present study, two freshwater fishes Channa punctatus and Clarias batrachus were exposed to sub-acute concentrations of a commercial-grade k-cyhalothrin, REEVA-5, for 96 h to observe the changes in amino acid catabolism under pyrethroidinduced stress and to investigate the comparative mechanisms of ammonia detoxification in both fishes. The experiments included the estimation of levels of free amino acid, urea, ammonia and the specific activities of aspartate aminotransferase (AAT), alanine aminotransferase (AlAT), glutamate dehydrogenase (GDH), glutamine synthetase (GS) and arginase in different vital organs of fishes. k-cyhalothrin caused significant decline in the levels of amino acids along with simultaneous significant increase in the activity of AAT, AlAT and GDH, which indicated amino acid catabolism as one of the important mechanisms to meet out immediate energy demand of fishes. The level of ammonia was observed to be enhanced considerably at lower concentrations of k-cyhalothrin while higher concentrations caused remarkable decline. The k-cyhalothrin treatment resulted in significant increase in the activities of GDH and GS with concomitant increase in the activity of arginase and level of urea, indicating activation of two different mechanisms of ammonia detoxification. The mechanism of ammonia detoxification through its conversion into glutamate and glutamine was more prominent in C. punctatus, while C. batrachus demonstrated ureogenesis as the major route. In fishwise comparison, C. batrachus was observed to be more sensitive with respect to the above-mentioned parameters. Another important finding was that unlike the liver, the kidney appeared as one of the primary sites of ureogenesis in fishes.

Alterations in nitrogen metabolism in freshwater fishes, Channa punctatus and Clarias batrachus, exposed to a commercial‐grade λ‐cyhalothrin, REEVA‐5

The developing countries of theworld are facing a global challenge of feeding their explosively
growing population. At the same time, the pests are becoming one of the major causes of preand
post-harvest loses of crops. The different types of broad-spectrum, effective pesticides
have been invented as a solution to this pest problem. However, Among these, the pyrethroid
group of insecticides are commonly being used. This review describes only two pyrethroid
i
the slowmetabolism of these compounds in fishes aggravate their toxic effects. In this review,
an updated account of the toxicological evaluation of both of these insecticides in terms of their
environmental, physico-chemical, metabolic, biochemical and molecular aspects has been
presentedwhichmay be useful in ecological risk assessmentandhumanhealthmanagement.
nsecticides namely !-cyhalothrin and cypermethrin, which are extensively being used in
different indoor and outdoor applications in order to kill the insects-pests. The recent reports the slowmetabolism of these compounds in fishes aggravate their toxic effects. In this review,
an updated account of the toxicological evaluation of both of these insecticides in terms of their
environmental, physico-chemical, metabolic, biochemical and molecular aspects has been
presentedwhichmay be useful in ecological risk assessmentandhumanhealthmanagement.

Toxicological assessment of pyrethroid insecticides with special reference to cypermethrin and λ-cyhalothrin in freshwater fishes

Altered bioenergetics and developmental effects in striped marsh frog (Limnodynastes peronii) tadpoles exposed to UV treated sewage.

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Toxic Effect of ?-Cyhalothrin on Biochemical Contents of Fresh Water Fish Channa punctatus

The chromosomal aberration test in kidney cells of Channa punctatus was conducted to study the genotoxic effect of synthetic pyrethroid fenvalerate, Different chromosomal abnormalities were seen and their frequency was recoded in metaphase spreads obtained from fishes exposed to three sub lethal concentrations (0.0625, 0.0314 and 0.0157 ppm) of this compound. The exposure to fenvalerate caused various structural abnormalities in chromosomes such as chromatid break, fragment, gap, chromatid separation, deletion and ring type chromosomes. Results obtained in present investigations clearly indicate that fenvalerate acts as a genotoxic agent in Channa punctatus.

https://journals.ansfoundation.org/index.php/jans/article/download/99/77

Study of chromosomal abnormalities in Channa punctatus exposed to fenvalerate

The frequency of chromosomal damage in Channa punctatus by using chromosomal aberration test when exposed to synthetic pyrethroid bifenthrin was investigated. The frequency was examined in metaphase spreads obtained from fishes exposed to different sublethal concentrations (0.016, 0.0347 and 0.0628 ppm) of bifenthrin. Control fishes were kept in tap water. Chromosomal preparations were made from kidney cells of Channa punctatus after 5, 10 and 15 days exposure. Different types of aberrations like chromosomal gap, sticky plates, chromatid separation and breaks were observed in the cells of fishes exposed to bifenthrin. These aberrations were found significantly higher as compared to that of control and were statistically significant at (p<0.05) level. These findings obviously indicated that bifenthrin caused genotoxicity in Channa punctatus.

https://www.alliedacademies.org/articles/evaluation-of-bifenthrin-genotoxicity-on-channa-punctatus.pdf

Evaluation of bifenthrin genotoxicity on channa punctatus

Effect of ?-cyhalothrin on the Activities of Trypsin and Lipase in Fresh Water Fish Channa punctatus

In the present study, complete ORF of GnRH receptor transcript from goat pituitary was amplified, cloned inprokaryotic system and sequenced. The goat type-I GnRH receptor sequence shows high homology with sheep, cow,buffalo, equine and human. Like in other mammalian species in goat too, the GnRH receptor lacks a C terminal tail.Amino acids which are critical for structure and function of the receptor were found conserved. Few amino acidresidues conserved amongst ruminants were found to be replaced in other mammalian species suggesting divergentevolutionary path of this gene in these groups.

/pdf/characterization-of-gene-encoding-type-i-gonadotropin-3q4idmvgaa.pdf

Kamal Kumar Saxena

Papers

Toxic Effect of ?-Cyhalothrin on Biochemical Contents of Fresh Water Fish Channa punctatus

Study of chromosomal abnormalities in Channa punctatus exposed to fenvalerate

Evaluation of bifenthrin genotoxicity on channa punctatus

Effect of ?-cyhalothrin on the Activities of Trypsin and Lipase in Fresh Water Fish Channa punctatus

Characterization of Gene Encoding Type-I Gonadotropin Releasing Hormone Receptor in Goat (Capra hircus)