Incidence of microplastics in Indian anchovy Stolephorus indicus from Tuticorin, Southeast coast of India.

In the present study, the occurrence of microplastics (MPs) in the gut, gill, and muscle of edible fish Stolephorus indicus sampled from Tuticorin coastal regions of Tamilnadu, India was investigated. We recorded a total of 689 MPs which includes 510 and 179 MPs from males and females respectively. The total abundance of MPs was significantly (P < 0.05) higher in the gut followed by gills and muscle. The sex-wise distribution of average MPs showed high in the females' gut and compared to that in males. Further, the length wise distribution of MPs was higher in the muscle in both male and female fish, followed by other organs. The predominance of MPs in tissues were transparent and blue colour with fibers and fragments in both males and females. Besides, polyethylene terephthalate and nylon were evidenced by the Fourier-transform infrared spectroscopy spectrum in all organs of fishes.

The effect of copper nanoparticles supplementation on freshwater prawn Macrobrachium rosenbergii post larvae.

The present study was performed to assess the effects of dietary supplementation of copper nanoparticles (Cu-NPs) on growth, biochemical constituents, digestive enzyme activities, antioxidant, metabolic enzyme levels, and non specific immune response of the freshwater prawn, Macrobrachium rosenbergii post larvae (PL). The Cu-NPs (200 nm) were synthesized by facile and environmental friendly hydrothermal method. Cu-NPs were supplemented at 0, 10, 20, 40, 60, and 80 mg kg(-1) with the basal diets. These Cu-NPs supplemented diets were fed to M. rosenbergii PL for 90 days. Results showed significant (P<0.05) improvements were observed in survival, growth, digestive enzyme activities, concentrations of biochemical constituents and total and differential haemocytes count of prawns fed with 20 mg Cu-NPs kg(-1) supplemented feed. Prawns fed with 40-80 mg Cu-NPs kg(-1) supplemented feed showed negative performance. Activity of antioxidants and metabolic enzymes in the muscle and hepatopancreas of prawns showed no significant alterations (P>0.05) prawns fed with up to 20 mg Cu-NPs kg(-1) supplemented feeds. Whereas, prawns fed with 40-80 mg Cu-NPs kg(-1) supplemented feed showed significant (P<0.05) elevations in antioxidant and metabolic enzymes activities. Hence, 40-80 mg Cu-NPs kg(-1) diets may have toxic effect to M. rosenbergii. Hence, present study suggests that 20 mg Cu-NPs kg(-1) can be supplemented for regulating better survival, growth and immune response of M. rosenbergii PL.

Dietary supplementation of zinc nanoparticles and its influence on biology, physiology and immune responses of the freshwater prawn, Macrobrachium rosenbergii.

The present study was conducted to assess the influence of dietary zinc nanoparticles (size 50 nm) on the growth, biochemical constituents, enzymatic antioxidant levels and the nonspecific immune response of the freshwater prawn, Macrobrachium rosenbergii post larvae (PL). The concentrations of dietary supplement zinc nanoparticles (ZnNPs) were 0, 10, 20, 40, 60 and 80 mg kg(-1) with the basal diet, and the level of Zn in ZnNP-supplemented diets were 0.71, 10.61, 20.73, 40.73, 60.61 and 80.60 mg kg(-1), respectively. ZnNP-incorporated diets were fed to M. rosenbergii PL (initial body weight, 0.18 ± 0.02 g) in a triplicate experimental setup for a period of 90 days. ZnNP supplemented feed fed PL up to 60 mg kg(-1) showed significantly (P < 0.05) improved performance in survival, growth and activities of digestive enzymes (protease, amylase and lipase). The concentrations of biochemical constituents (total protein, total amino acid, total carbohydrate and total lipid), total haemocyte count and differential haemocyte count were elevated in 10-60 mg kg(-1) ZnNP supplemented feed fed PL. However, the PL fed with 80 mg ZnNPs kg(-1) showed negative results. Activities of enzymatic antioxidants [superoxide dismutase (SOD) and catalase (CAT)], metabolic enzymes [glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT)] and the process of lipid peroxidation (LPO) in the hepatopancreas and muscle showed no significant alterations in 10-60 mg kg(-1) ZnNP supplemented feed fed PL. Whereas, 80 mg ZnNPs kg(-1) supplemented feed fed PL showed significant elevations in SOD, CAT, LPO, GOT and GPT. Therefore, 80 mg ZnNPs kg(-1) was found to be toxic to M. rosenbergii PL. Thus, the study suggests that up to 60 mg ZnNPs kg(-1) can be supplemented for regulating survival, growth and immunity of M. rosenbergii.