Objective:

To synthesize current knowledge on the effects of plastic exposure on feeding, digestion, metabolism, and growth in aquatic ectotherms, particularly fish, while integrating evidence from amphibians and reptiles.

Approach:

• Review of Literature: The article reviews existing studies on the impact of microplastics (MPs) and nanoplastics (NPs) on aquatic ectotherms, focusing on physiological processes and the influence of environmental conditions.

Key Findings:

• Plastic exposure disrupts energy balance by reducing food intake through false satiety, gastrointestinal obstruction, and behavioral alterations.
• Endocrine signaling pathways involved in appetite regulation and metabolism are disrupted by plastic exposure.
• Oxidative stress and impaired hepatic function are common consequences of plastic contamination.
• Environmental conditions such as temperature and salinity modulate the effects of plastics on aquatic organisms.

Interpretation:

The review synthesizes significant physiological disruptions caused by plastics in aquatic ectotherms, particularly in fish.

Limitations:

• High heterogeneity in experimental protocols, including differences in plastic characteristics, exposure concentrations and durations, species, and life stages, limits direct comparison across studies.
• Evidence in reptiles remains limited and largely observational.

Conclusion:

Further research is needed on the mechanisms and effects of plastic exposure in aquatic ecosystems.