Contamination of microplastics in Brantas River, East Java, Indonesia and its distribution in gills and digestive tracts of fish Gambusia affinis

The Brantas River is currently vulnerable to microplastics pollution.Microplastics not only pollute the aquatic environment but also enter the body of fish and other aquatic organisms.This research is aimed at deciding if microplastics were present in the waters and the gills and digestive tract of the Gambusia affinis fish of the river.It also looked at differences in the abundance of several types of microplastics found in the various organ samples and locations.Field research was conducted from January 2020 to March 2020.The microplastics were identified by type,size,color,and the abundance of each type was calculated.The types of microplastics identified were fragments,fibres,films,and pellets.Microplastics of 0.1 mm size are predominant and formed about 76%-100%of the microplastics that were found.Black microplastics were more common in water samples(24%),gills(43%),and digestive tract(46%).The greatest abundance of microplastic fragments was found in water samples of 4066.67 particles/m^(3),1352.78 particles/gram in gill samples,and 2138.89 particles/gram in the digestive tract.Multivariate tests for variants of microplastic types found in the organs at different sampling locations gave a p-value<0.05.These results indicate a difference in the abundance values of microplastic species in different organ samples and sites.

Change of osmoregulatory and hematological parameters in tilapia(Oreochromis niloticus)after exposure to sublethal mercury concentrations

The effects of Hg exposure on blood parameters and gill physiology of tilapia(Oreochromis niloticus)were analyzed.Fish maintained in freshwater were exposed for 7 days(d)to sublethal mercury concentrations(0.1 and 1 mg/L).Blood serum osmolality(SO),sodium(Nat),potassium(K^+)and chloride(Cl^-)ionic concentrations,and hematological parameters were assessed after 1 up to 7 d of exposure.Serum osmolality and ionic concentrations of exposed fish appeared differently affected throughout the experimental period compared to the controls.Osmolality was reduced at the 2 tested concentrations but Nat and Cl^-contents were only altered at 1 mg/L of Hg after 1 d of exposure and values rapidly returned to the control values thereafter.K^+content was also modified and significantly increased at both concentrations after 1 d of exposure but returned to the control values after 3 d of exposure.Red blood cell(RBC),white blood cell(WBC)and hemoglobin(Hb)levels were significantly increased throughout the experiment but returned to control values after 7 d of exposure only for the 0.1 mg/L concentration.The hematocrit(Ht)levels remained unaffected due to Hg exposure.Therefore,tilapias exposed to sublethal concentrations of Hg present a marked osmotic imbalance with ionic and hematological disorders that are rapidly compensated.

CD4 cell activation with the CD8 marker and metallothionein expression in the gills of cadmium-exposed mosquito fish(Gambusia affinis Baird and Girard 1853)juveniles

This experiment aimed to determine how Cd exposure impacts CD4 cell activation,macrophage cells,pinocytosis activity,metallothionine expression,and Cd levels in juvenile Gambusia affinis gills.Four treatment groups were used,with one control and treatments A,B,C,and D at dosages of 0.03 mg/L,0.023 mg/L,0.015 mg/L,and 0.008 mg/L,respectively.The results showed that the number of CD4 with CD8 cell markers differed significantly from each treatment compared to the control(0.33%).The value in A,namely 0.54%,was the highest,followed by B,C,and D of 0.46%,0.44%,and 0.42%,respectively.The number of macrophages increased as the Cd level of the medium increased,as did the activity of pinocytosis.Furthermore,the immunofluorescence test on the gills with the Anti-MT Mouse and goat IgG fluoresce in Rhodamine on the gills showed that luminescence increased with increasing Cd levels in the gills.Similarly,the MT intensity increased at Cd-exposed gills as compared to the control.As the Cd level in the gills increased,the MT levels ascended significantly.