Toxicological assessment of dietary exposure of polyethylene microplastics on growth, nutrient digestibility, carcass and gut histology of Nile Tilapia (Oreochromis niloticus) fingerlings

Ecotoxicology. 2024 Apr;33(3):296-304. doi: 10.1007/s10646-024-02749-9. Epub 2024 Mar 18.

Abstract

This study was conducted to ascertain the negative effects of dietary low-density polyethylene microplastics (LDPE-MPs) exposure on growth, nutrient digestibility, body composition and gut histology of Nile tilapia (Oreochromis niloticus). Six sunflower meal-based diets (protein 30.95%; fat 8.04%) were prepared; one was the control (0%) and five were incorporated with LDPE-MPs at levels of 2, 4, 6, 8 and 10% in sunflower meal-based diets. A total of eighteen experimental tanks, each with 15 fingerlings, were used in triplicates. Fish were fed at the rate of 5% biomass twice a day for 60 days. Results revealed that best values of growth, nutrient digestibility, body composition and gut histology were observed by control diet, while 10% exposure to LDPE-MPs significantly (P < 0.05) reduced weight gain (WG%, 85.04%), specific growth rate (SGR%, 0.68%), and increased FCR (3.92%). The findings showed that higher level of LDPE-MPs (10%) exposure in the diet of O. niloticus negatively affects nutrient digestibility. Furthermore, the results revealed that the higher concentration of LDPE-MPs (10%) had a detrimental impact on crude protein (11.92%) and crude fat (8.04%). A high number of histological lesions were seen in gut of fingerlings exposed to LDPE-MPs. Hence, LDPE-MPs potentially harm the aquatic health.

Keywords: Oreochromis niloticus; Carcass; Growth performance; Gut histology; Microplastics.

MeSH terms

  • Animal Feed / analysis
  • Animals
  • Cichlids*
  • Diet
  • Dietary Exposure / adverse effects
  • Dietary Supplements
  • Microplastics / metabolism
  • Nutrients
  • Plastics
  • Polyethylene / toxicity

Substances

  • Polyethylene
  • Microplastics
  • Plastics