Toxic Effects of Arsenic in Commercially Important Fish Rohu Carp, Labeo rohita of Bangladesh

Abstract

This study was designed to elucidate the effects of arsenic (As) on the morpho-behavior, growth development and molecular mechanisms of a commercially important fish, rohu carp, Labeo rohita, in Bangladesh. Fish fry with an average weight of 387.5 ± 169.25 mg and an average length of 3.35 ± 0.37 cm were collected from a local hatchery in Mymensingh, Bangladesh and acclimatized for a week in the Department of Fisheries, University of Dhaka before starting the exposure with arsenic. Fishes were exposed for a period of 14 days with three treatments of NaAsO2, namely treatment 1(T1)—2.5 mg/L; treatment 2 (T2)—15 mg/L; and treatment 3 (T3)—30 mg/L, along with a control (C)—0.0 mg/L, with three replicates. These concentrations were determined based on the LC50 value for 96 h measured for this experiment. This study revealed remarkable morphological abnormalities and deformities in arsenic-exposed rohu carp. In fish exposed to 30 mg/L, caudal fin erosion was a frequent deformity. There was no significant difference in RNA:DNA ratio among the treatments. The overall weight of fish was decreased as the concentration of arsenic was increased. The T3 fish had a statistically significant negative weight gain (−0.05 ± 0.07 g), but the other treatments (T1 and T2) and control fish had no significant weight gain. Different types of histopathological changes were observed in the gills and intestines of arsenic-treated fish. Necrosis and severe damages were found in the secondary lamellae of gills at the highest arsenic concentration (30 mg/L). Epithelial lifting, irregular shape and damages in the gill raker were also observed in the primary lamellae of the gills for the same treatment. In this study, the expression of heat shock protein (HSP 60) and metallothionein (MT) genes was assessed by qPCR, and these genes were upregulated in different treatments compared to controls. The findings of the present study suggest that arsenic pollution significantly changes the morphology, behavior, growth, development, histopathology and molecular mechanisms of this economically important fish, rohu carp, in Bangladesh.

Toxicity Evaluation, Oxidative, and Immune Responses of Mercury on Nile Tilapia: Modulatory Role of Dietary Nannochloropsis oculata

“…In a similar context, Hg 2+ toxicity of HgCl 2 -exposed Nile tilapia under thermal stress conditions was marked by a reduction of the antioxidant enzymes, including GPx, in the serum, while a remarkable upregulation of the HSP-encoding gene was noticed in the lateral muscles [ 63 ]. More recently, arsenic (As) heavy metal exposure elevated the expression of stress-relevant genes, including HSP, in rohu carp fries [ 66 ].…”

Understanding feeding competition under laboratory conditions: Rohu (Labeo rohita)versus Amazon sailfin catfish (Pterygoplichthysspp.)

“…If so, does it depend on the body size (TL, as a proxy for age, Raphael et al, 2016) of both species? Feeding duration of each species was used as a proxy to understand competition. The purpose of the study is to understand feeding competitions between Amazon sailfin catfish and rohu to help understand any potential impact of the invasive catfish (Parvez et al, 2023; Wakida-Kusunoki et al, 2007) on the keystone and commerciallly valuable species, rohu (Dwivedi and Nautiyal, 2012; Dwivedi et al, 2020; Rabbane et al, 2022; Mallick et al, 2023). Such understanding may help in assessing the threats associated with several ecosystems across the globe, where the native rohu now co-occur with the invasive catfish (Wakida-Kusunoki et al, 2007; Saba et al, 2020; Seshagiri et al, 2021; Parvez et al, 2023).…”

“…The purpose of the study is to understand feeding competitions between Amazon sailfin catfish and rohu to help understand any potential impact of the invasive catfish (Parvez et al, 2023;Wakida-Kusunoki et al, 2007) on the keystone and commerciallly valuable species, rohu (Dwivedi and Nautiyal, 2012;Dwivedi et al, 2020;Rabbane et al, 2022;Mallick et al, 2023).…”

Effect of Toxicity of Chromium (VI) Stressors Alone and Combined to High Temperature on the Histopathological, Antioxidation, Immunity, and Energy Metabolism in Fish Phoxinus lagowskii

“…Tissue histopathological investigation is a valuable method to assess the effects of environmental contaminants on the vital organs of fish under laboratory conditions [21]. The extent of pathological changes in different organs of fish is determined by the magnitude of the concentration and duration of exposure to pollutants [22]. Gills serve as the initial organs that are adversely affected in fish, which are highly susceptible to infection from water pollutants due to constant exposure, and respiratory problems serve as significant and early indicators of pollution exposure [23].…”