The use of natural anesthetics, such as essential oils, is increasingly relevant in aquaculture to improve the management of economically important species such as tambaqui (Colossoma macropomum). This study investigated the anesthetic potential of basil (Ocimum basilicum L.) essential oil (OBEO), primarily composed of estragole (77.71
The average global temperature has increased significantly in recent decades due to anthropogenic activities. In aquatic environments, rising temperatures act as a major thermal stressor, affecting fish growth and development. However, little is known about the effects of elevated temperatures on the liver tissue of Astyanax lacustris, a species of importance in aquaculture. Thus, this study investigated the effects of high temperature (32 °C) and exposure duration on liver histopathology in A. lacustris. Forty males were maintained in a recirculating aquaculture system under two temperatures (26 °C and 32 °C) and evaluated after 30 and 210 days of exposure. Histopathological alterations such as leukocyte infiltration, cytoplasmic vacuolization, and hyperemia were observed at low frequencies, associated with both exposure time and elevated temperature. Vascular congestion, a more severe condition that can compromise liver function, was not directly related to temperature increase; however, it was associated with the reproductive period. The histopathological index indicated mild to moderate damage at 26 °C after 30 days, whereas normal hepatic function was preserved in all other groups. Overall, the low incidence and severity of lesions indicate that A. lacustris can maintain liver integrity when exposed to temperatures up to 32 °C in recirculating water systems. These findings suggest a degree of hepatic resilience to warming conditions, although longer-term exposure may increase the risk of tissue alterations, highlighting the need for further investigations under climate change scenarios.
Aquatic ecosystems are increasingly threatened by anthropogenic pollutants, among which pesticides are widely detected and recognized as potent endocrine-disrupting chemicals. These compounds interfere with hormonal regulation in fish, leading to adverse effects on growth, development, reproduction, and behavior. However, a consolidated mechanistic understanding linking pesticide exposure to dysfunction of endocrine pathways, particularly the hypothalamic–pituitary–gonadal axis, remains insufficient. This review critically synthesizes current evidence on pesticide-induced endocrine disruption in fish, with a primary focus on reproductive impairment. Available studies demonstrate that pesticide exposure alters hormone levels, disrupts gametogenesis, alters neuroendocrine signaling, and induces behavioral abnormalities, collectively compromising reproductive success. Key biomarkers, including vitellogenin induction, histopathological changes, behavioral responses, and genomic indicators are identified as reliable tools for detecting endocrine dysfunction. The review further highlights how pesticide-driven reproductive toxicity may contribute to population declines and broader ecological instability. By integrating mechanistic insights into organism-level outcomes, this synthesis underscores the ecological risks posed by endocrine-disrupting pesticides (EDPs) and emphasizes the need for improved environmental monitoring, risk assessment frameworks, and regulatory strategies. Given the global reliance on pesticides and the rising incidence of aquatic contamination, understanding endocrine-mediated reproductive toxicity is essential for safeguarding fish populations and maintaining ecosystem resilience.
Supplementing dried fish soluble (FS) in a high soybean meal (SBM)-based diet could ameliorate the adverse impacts of high SBM on fish gut health. This study aimed to determine the impact of supplementing dried FS in the high SBM-based diet on rainbow trout (Oncorhynchus mykiss) across two strains through gut histology and gut-liver axis–related gene expression. A total of 600 fish (22.1 g) were randomly distributed to 30 tanks (20 fish/tank) in a recirculating aquaculture system following a 2 × 5 factorial design. Five experimental diets, fishmeal-based, SBM at 20
The increasing production of nanomaterials has raised concerns regarding their environmental presence and potential adverse effects on non-target aquatic species. This study investigated the physiological impacts of acute (24 h) exposure of Oreochromis niloticus to copper oxide nanoparticles (CuO-NPs) of two distinct morphologies: nanorods (NRs) and nanospheres (NSs). Nanoparticles were synthesized and characterized via transmission electron microscopy, revealing significant differences in size, shape, and colloidal stability. Juvenile tilapia was exposed to concentrations ranging from 50 to 800 µg/L to evaluate routine metabolism (specific oxygen consumption), ammonia excretion, and swimming performance to fatigue. Both NRs and NSs significantly altered physiological parameters with distinct patterns. Oxygen consumption increased dose-dependently, reaching a 51
