animal studies have shown that MPs can lead to physical damage and histopathological alterations in the intestines and can even change swimming behavior and the lipid metabolism [17; 18; 19; 20]. We suspected that these adverse effects are generally observed in acute toxicity studies with high concentrations of MPs that may not be present in the real environment. Moreover, most MPs exposure test used regular shape microspheres as materials, while spheres were not the common shape found in MPs field investigations. The chosen concentration and shape of MPs should be reliable in the experimental design as for the caution of potential harm in aquaculture. The definition of virgin MPs is opposite to commercial MPs. Virgin MPs mean the materials of MPs from human daily life, and generally with no uniform shape. Fibers, fragments and films, are common shapes of virgin MPs, which also commonly found in water and organisms. Few studies have reported harm to the organism coming from virgin MPs. It seems unclear whether virgin MPs cause imminent harm to fish or not, as different researchers have shown discrepant results. For example, there was no significant difference in fish mass between control group and harbor collected plastics treatment, which fed to small juvenile glassfish (_Ambussis dussumieri_) daily for 95 d [21]. Similarly, there were no significant differences in growth performance of gilthead seabream (_Sparus aurata_) with an experimental diet containing 500 mg kg\({}^{-1}\) of PVC-MPs for 30 d [22]. In a related study, exposure to six common types of virgin MPs in the diet of gilthead seabream caused no observable pathology or change in growth rate [23]. Furthermore, virgin industrial MPs extracts showed no toxic effect on early life stages of Japanese medaka (_Oryziaz latipes_) [24]. After 45 d exposure period, variations in body weight and survival rate of African catfish (_Clarias gariepinus_) were not significantly different among the PVC-treated groups relative to the control, although fish were fed PVC MPs spiked diets at maximum 3% [25]. However, virgin MPs altered blood biochemical parameters and changed the transcription of the reproductive-axis genes of African catfish [26]. Furthermore, researchers have also shown that marine-derived fishmeal might be a source of MPs, which could be transmitted to farmed fish, thus causing a concern in the aquaculture industry [27]. Still, the effect of virgin MPs on aquaculture is not clear. Recently, severe MPs pollution was found in the aquaculture water of fish ponds from the Pearl River Estuary [14], which raised concerns about the safety of aquatic production. To address these concerns, this study aimed to investigate the effect of two kinds of virgin MPs on commercial fish health. We chose largemouth bass (_Micropterus salmonides_) as a biological model, given its key role in the Chinese fishery market as well as other important parameters, including physiological characteristics, high predation rate, and upper-middle dwelling [28; 29]. The amount of Chinese production of bass was 477,808 tons in 2019 (China fishery Statistical Yearbook, 2020). The shapes of MPs in this study were restricted to fragments and fibers, since these are the most predominant shapes of MPs found in aquatic environments and in fish [3; 30]. The size of MPs was 3-4 mm, and material of MPs used in this study was polypropylene, which were related to actual contamination. It was also reported that the contamination of seafood-based feeds by MPs threaten the fish health [31]. In reference to the sources of MPs that farmed fish may be exposed to, we set up two exposure ways (water and feed). The exposure concentrations of virgin MPs in water and feed were set according to previous field results [3] and study [23]. The objectives of this study were to expose largemouth bass to two shapes of virgin MPs in water and feed, finally assess their growth, intestinal morphology and microbial after four weeks. Four groups were divided according to whether the MPs were added in water or in food.