Microplastics in catfish Pterygoplichthys pardalis (Castelnau 1855) and Hoplosternum littorale (Hancock, 1828) marketed in Itacoatiara, Amazonas, Brazil

Contamination by microplastics (MPs) has been recorded in various environments and organisms around the world. The objective of this study was to investigate the occurrence of MPs in two species of Siluriformes fishes Pterygoplichthys pardalis and Hoplosternum littorale considering the sex and different body parts of fish captured in Amazon floodplain areas, which are marketed and consumed in the Municipality of Itacoatiara, Amazonas, Brazil. One hundred and fifty individuals of each fish species were analyzed for microplastics. Of these, 252 individuals were found to contain MPs: 127 (85%) P. pardalis and 125 (83%) H. littorale. The fish were contaminated with 683 MP particles, ranging from 1 to 43 MP particles/individual, with an average of 2.71 ± 3.2 MP particles/individual P. pardalis and H. littorale. Comparison of MP occurrence and particle size between species, sex, and body part found no significant difference. Fiber-shaped and blue-colored MPs were the most abundant in both P. pardalis (80% and 85.5%, respectively) and H. littorale (92% and 85%, respectively). The particles were identified as polyethylene terephthalate and polystyrene. The results indicate MP contamination in P. pardalis and H. littorale catfish, which are widely consumed by Amazonian riverside communities. These species are often cooked whole (including the viscera) becoming a direct route of microplastic contamination to humans.