Microplastic pollution has been identified as a potential threat to the aquatic environment and humans globally, with widespread occurrence in ecosystems, including reservoirs that constitute a key role in ecosystem services for humans. However, the evaluation of microplastic pollution in reservoirs is limited, especially in inland fishing ground reservoirs. The spatial and temporal distributions of microplastics in surface water and sediment at 13 stations of the Ubolratana Reservoir, Thailand, were assessed during the wet and dry seasons. The abundance and morphological characteristics of the microplastics were identified and classified by color, shape, size and polymer type. Microplastic abundance in surface water and sediment ranged between 25 and 3363 particles/m3 and 6 and 81 particles/kg, respectively. Seasonal variations impacted microplastic abundance in surface water, while tourism activity in the reservoir also influenced the abundance and morphological characteristics of microplastics. A microplastic risk assessment showed that the pollution load index reached extremely high levels in surface water during the dry season in tourist areas. The results provide a database to assess the risk of microplastic contamination and to monitor plastic pollution in lentic ecosystems, including preserving the health of aquatic habitats.
Pinctada fucata, the pearl oyster, is a bivalve primarily cultivated for the production of saltwater pearls. In this study, the genome-wide association study (GWAS) for the growth-related traits and a principal components analysis (PCA) in P. fucata were performed. Genomic parameters of 6 growth-related traits in 60 individuals were estimated by using 4,937,162 single-nucleotide polymorphisms (SNPs). A total of 45 SNPs associated with growth traits were thus identified. Furthermore, 165 candidate genes were identified, including collagen alpha-3 (VI), serine/threonine-protein kinase mos-like harboring significant markers, and histidine-rich protein PFHRP-III-like, which may influence growth-related traits associated with various biological processes. The results of this study can facilitate marker-assisted selection and breeding programs designed to enhance growth and also offer a theoretical foundation for the further development and utilization of genomic resources in P. fucata.
The aim of this study was to evaluate the utilization of fairy shrimp (Branchinella thailandensis) meal in the diets of flowerhorn cichlids, on their growth, skin coloration, carotenoid content, antioxidant activity, and innate immunity. The fish were fed diets incorporated with fairy shrimp meal at 0% (control; FS0), 10% (FS10), 20% (FS20), and 30% (FS30) for 60 days. The results showed that growth performance and chemical composition were not significantly different among treatments (p > 0.05), whereas fish fed the 30% fairy shrimp meal (FS30) diet represented significantly enhanced skin coloration, particularly in terms of redness (a*) and dominant wavelength (H°ab). The highest level of antioxidant enzymes and non-specific immune enzymes such as SOD and lysozyme were observed in the fish fed the FS30 diet. Meanwhile, increasing fairy shrimp meal significantly reduced the liver function markers (ALT and AST), and decreased lipid peroxidation. These findings suggest that fairy shrimp meal serves as a valuable dietary ingredient for enhancing skin pigmentation, boosting antioxidant defense, and stimulating immune responses in flowerhorn cichlids. Moreover, the economic evaluation of using fairy shrimp meal as an ingredient for ornamental fish demonstrates promising investment potential, supporting its application in commercial aquaculture.
This study examined the life characteristics, fecundity, and innate immune response of fairy shrimp (Branchinella thailandensis Sanoamuang, Saengphan and Murugan, 2002) cultivated on Chlorella vulgaris, biofloc, dried powder Spirulina sp., and a formulated feed. These feeds were selected to compare traditional live feed (Chlorella vulgaris), microbial-based feed (biofloc), and alternative dry feed in order to identify a sustainable feeding strategy for fairy shrimp culture. The lifespans of male and female fairy shrimp reared on the biofloc diet were the longest at 44 ± 6.00 and 44.33 ± 4.67 days, respectively. Fairy shrimp reared on the biofloc diet demonstrated significantly enhanced growth, with lengths of 25.66 ± 1.75 mm in males and 27.60 ± 2.08 mm in females. The highest fecundity was also observed in the biofloc treatment, with 25 ± 6.65 broods per female, an average of 229.57 ± 2.08 eggs per brood, and a total of 5726.33 ± 1518.11 eggs per female over their lifespan. Fairy shrimp fed with Chlorella vulgaris, biofloc, and Spirulina sp. showed significantly high levels of superoxide dismutase (SOD) and lysozyme activities compared to those fed on a formulated feed, while malondialdehyde (MDA) levels, a marker of oxidative stress, were lower in these three groups. Results suggested that biofloc was a viable feed option for B. thailandensis, which positively influenced growth, lifespan, and fecundity while enhancing the innate immune function.