Kizar Ahmed Sumon

Pesticides have become an integral part of agricultural crop production for growing more food. However, the excessive use of pesticides ultimately reaches the aquatic ecosystems and demonstrates pernicious impacts on non‐target aquatic organisms, including fish. Hence, the current study aimed at unravelling the chronic toxicity of an organophosphate insecticide, chlorpyrifos (CPF), on a battery of blood biomarkers, somatic indices and histopathological aberrations of liver and kidney in banded gourami ( Trichogaster fasciata ). Fish were subjected to different sub‐lethal concentrations (0, 15, 50, 150 and 500 µg/L) of CPF for 75 days, and sampling was done at each 15‐day interval. Results indicated a significant rise ( p < 0.05) in glucose, white blood cell levels, mean corpuscular volume and mean corpuscular haemoglobin, and a subsequent decrease in haemoglobin, red blood cell count and packed cell volume. Hepatosomatic index exhibited an increasing pattern, whereas the kidney somatic index followed the opposite trend. Vacuolation, fatty degeneration, dilation of sinusoids and haemorrhage were evident in the liver, whereas kidney histopathology revealed occlusion of the tubular lumen, widened intertubular space, vacuolation, melanomacrophage centre and haemorrhage. Overall, chronic CPF exposure exerted concentration‐ and time‐dependent alterations resulting in anaemia, hepatotoxicity and nephrotoxicity in banded gourami. However, more in‐depth studies are required to understand the changes in fish at the molecular level, such as oxidative stress, gene expression, metabolomic profiling and so forth. The study encourages research for pesticide alternatives and interdisciplinary actions to conserve the aquatic environment as well as the aquatic biota.

Polypropylene microplastics (PP‐MPs) are widely distributed in aquatic environments and may harm fish through ingestion. Despite growing research on microplastic toxicity, very limited study prevails on the pernicious impacts of waterborne PP‐MPs on Nile tilapia. Hence, this study aims to examine the impact of PP‐MPs on the growth, hematobiochemical parameters, erythrocytes, and histopathology in male Nile tilapia ( Oreochromis niloticus ). Juvenile Nile tilapia was exposed to water‐borne PP‐MPs (0, 0.1, 1, and 10 mg/L) for 28 days in glass aquaria in a chronic semi‐static exposure system. Specific growth rate (SGR) was calculated on the basis of established formulas, hematological and biochemical parameters, and histology were assessed using standard laboratory protocols; and subsequently histopathological slides were evaluated microscopically. Weight gain and SGR were reduced significantly, with the highest concentration (10 mg/L) showing the most noticeable decline. A marked decrease in red blood cell (RBC) count, hemoglobin (Hb) levels, and packed cell volume (PCV) was noted. Conversely, white blood cell (WBC) count and blood glucose levels significantly increased, indicating a physiological stress response. Nuclear abnormalities such as blebbed nuclei, karyopyknosis, micronuclei, notched nuclei, and nuclear bridges were observed, indicating potential genotoxic effects. Cellular abnormalities, including fusion, teardrop, twin cells, and spindle‐shaped erythrocytes, were noted, reflecting structural deformities in cell morphology. Gill, liver, and intestinal histology exhibited clear deterioration in the highest exposure group (10 mg/L), especially at later sampling times. These findings highlight the detrimental impact of waterborne PP‐MPs on fish health, emphasizing the urgent need for further research into their long‐term ecological consequences.

Plastic pollution has become a critical environmental issue in coastal and estuarine ecosystems, raising concerns about its impact on ecologically and economically important crustaceans such as mud crabs (Scylla spp.). This review synthesizes current research on the occurrence, characteristics, and toxicological effects of plastic contamination in mud crabs. A systematic literature search identified 15 relevant studies published between 2022 and 2025, including 13 that reported the presence of plastics in mud crabs and 2 that examined physiological impacts. Microplastics were the predominant size class, primarily in the gastrointestinal tract, followed by the gills and hepatopancreas. Fragments and fibers were the most common shapes observed, while blue, transparent, and black were the dominant colors. Twelve polymer types have been documented, with polyethylene (PE) and polypropylene (PP) most frequently reported, reflecting their widespread use and prevalence in mangrove and estuarine environments. Plastic abundance varies substantially across regions, species, and tissue types. Toxicological evidence indicates that microplastics tend to accumulate in various fish tissues, particularly in the digestive and respiratory organs, leading to oxidative stress, altered antioxidant enzyme activity, and DNA damage. Despite these emerging findings, substantial knowledge gaps persist, including the absence of data on muscle contamination, limited comparisons between wild and farmed crabs, lack of sex-based assessments, and minimal understanding of impacts on early developmental stages. This review highlights the urgent need for standardized methodologies and comprehensive ecotoxicological studies to improve understanding of plastic exposure pathways, physiological responses, and the broader ecological and food-safety implications for Scylla spp. populations.

The indiscriminate and excessive use of pesticides ultimately reaches the aquatic ecosystems and results in detrimental impacts on fish and other aquatic species. The current study focused on elucidating the acute toxic effects of the organophosphate pesticide, profenofos, on various blood biomarkers in banded gourami ( Trichogaster fasciata ). Fish were subjected to different sub‐lethal concentrations (0%, 5%, 10%, 20%, and 40% of the 96‐h LC ₅₀ = 2972.7 μg/L) of profenofos for 1, 24, and 96 h. Fish exposed to profenofos induced a significant rise ( p < 0.05) in glucose, white blood cell levels, mean corpuscular volume, and mean corpuscular hemoglobin and a subsequent decrease in hemoglobin, red blood cell count, and packed cell volume. Furthermore, erythrocytic nuclear abnormalities such as micronucleus, notched nucleus, karyopyknosis, and blebbed nucleus, and erythrocytic cellular abnormalities such as elongated, fusion, spindle, tear‐drop, and twin‐shaped cells were observed. These abnormalities displayed a dose‐ and time‐dependent increase compared with the control. This study underscores the detrimental impact of the prevalent utilization of profenofos within aquatic environments and highlights the need for interdisciplinary actions to conserve the aquatic environment as well as the aquatic biota.

The present study was conducted to understand the changes in gonads and hematological parameters in climbing perch (Anabas testudineus) exposed to synthetic estrogen and progestogen [mixture of ethinylestradiol (EE2) and desogestrel (DES)]. Climbing perch were exposed to four different concentrations of EE2/DES mixtures, viz. 0 ng of EE2 and DES/L (T0), 3 ng EE2 and 15 ng DES/L (T3), 30 ng EE2 and 150 ng DES/L (T30), and 300 ng EE2 and 1500 ng DES/L (T300) for 60 days. On days 45 and 60, samples were taken to assess changes in somatic indexes, gonad histology, and hematological parameters. The gonadosomatic index (GSI) increased in both females and males with increasing concentrations of estrogen mixtures except for T30 females, which was the lowest among all\four treatments. The hepatosomatic index (HSI) was observed to be increased in males as estrogen content increased. However, compared to fish at T0, HSI in female individuals did not vary in T30 fish, where the value was the highest among all the treatments. On day 45, histological observations showed no feminization or intersexuality but several germ-cell deformities in the ovary (adhesion, degenerated oocyte wall, degenerated granulose layer, increased interfollicular space, atretic follicle, and cytoplasmic clumping) and testes (increased interstitial area, focal loss of spermatocyte, dilation of the lumen, breakage of tubular epithelium, and elongated seminiferous tubule) were observed in fish exposed to EE2 and DES. Fish reared at T30 had lower RBC count, hemoglobin (Hb), glucose, and hematocrit levels. On day 60, fish reared at T30 had the highest Hb content compared to fish raised in other treatment conditions. WBC was progressively higher with increasing EE2/DES concentrations. Significant erythrocyte cytoplasmic abnormalities and erythrocyte nuclear abnormalities were observed in fish exposed to higher EE2/DES concentrations. The present study provides insights into the adverse impacts of synthetic estrogens sourced from human contraceptive pills on fish physiology.

The burden of pesticide use from agricultural intensification lies in the fact that pesticides may end up in aquatic ecosystems and have pernicious effects on non-target organisms, including fish. Different blood biomarkers, including hemato-biochemical indices, erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA), were observed in Nile tilapia (Oreochromis niloticus) after exposure to varying sub-lethal concentrations (0%, 5%, 10%, 20%, and 40% of 96-h LC50) of profenofos at different time intervals (7, 14, 21, and 28 days). The results revealed that glucose and white blood cell (WBC) levels significantly increased, while hemoglobin, red blood cell (RBC), and packed cell volume (PCV) significantly decreased in a time- and concentration-dependent manner. Aberrant erythrocytic morphology-derived ENA, such as nuclear degeneration, micronuclear formation, binuclear development, nuclear budding, and karyopyknosis, significantly increased with time in profenofos-exposed groups compared to controls. Between the treatment and control groups, a significant execution was discerned for teardrop and fusion type ECA. For other cellular aberrations of erythrocytes, including elongated, twin, and spindle, a significant difference appeared only at the beginning of the experiment (day 7). This study concludes that the presence of widely used profenofos in aquatic systems has a pernicious effect on Nile tilapia.