Gill Histopathology as a Biomarker for Discriminating Seasonal Variations in Water Quality

Histopathological alterations in various fish organs have a pronounced value in aquatic toxicology and are widely used in environmental monitoring. The aim of this study was to evaluate whether histopathological alterations in fish gills can discriminate seasonal variations in environmental conditions within the same aquatic ecosystem, and if so, which alterations contributed the most to seasonal differentiation. Microscopic examination of common bream Abramis brama gills displayed various alterations in gill structure, including epithelial hypertrophy, hyperplasia, mucous and chloride cell alterations, epithelial lifting, necrosis, hyperemia and aneurism. These alterations were subsequently quantified by a semi-quantitative analysis in order to detect differences in the intensity of the mentioned alterations. Epithelial hypertrophy, hyperplasia, epithelial lifting and necrosis varied significantly between seasons with only necrosis being significantly higher in the first season. Discriminant canonical analysis displayed that epithelial hyperplasia, mucous cell alterations, epithelial lifting and necrosis contributed the most to discrimination between seasons. Overall, this study demonstrates that histopathological biomarkers in fish gills can be used in discriminating seasonal variations in water quality within the same aquatic ecosystem.

Penggunaan Fourier Transform Infrared untuk Analisis Mikroplastik pada Loligo sp. dan Rastrelliger sp. dari TPI Tambak Lorok Semarang

Mikroplastik adalah salah satu pencemar laut. Mikroplastik tidak dapat terdegradasi dengan cepat. Mikroplastik merupakan partikel plastik yang berukuran <5mm. Ukurannya yang kecil menyebabkannya dapat tertransportasikan ke seluruh tempat termasuk sistem tubuh ikan dan cumi-cumi. Penelitian dilakukan bertujuan mengetahui mikroplastik pada cumi – cumi (Loligo sp.) dan ikan kembung (Rastrelliger sp.). Penelitian dilakukan bulan Juli 2020 – November 2020 di Semarang Jawa Tengah. Pengambilan sampel dilakukan di TPI Tambak Lorok Semarang. Pengukuran cumi-cumi dilakukan menggunakan jangka sorong dan ikan diukur menggunakan penggaris. Pembedahan cumi-cumi dan ikan dilakukan menggunakan gunting bedah untuk memisahkan alat pencernaan, tentakel serta insang ikan yang akan digunakan sebagai sampel. Pelarutan dilakukan menggunakan perendaman KOH 10% selama 24 jam untuk melarutkan bahan organik. Pemisahan partikel mikroplastik dilakukan setelah seluruh bahan organik pada sampel larut seluruhnya. Pemisahan partikel mikroplastik dilakukan menggunakan perendaman ZnCl2 selama 24 jam. Penyaringan sampel dilakukan setelah sampel mempunyai 2 layer, layer pertama diambil 10 ml kemudian disaring menggunakan kertas whatman dengan vacump pump. Sampel yang telah disaring dikeringkan, dilanjutkan uji FTIR. Hasil penelitian menunjukkan bahwa terdapat mikroplastik dalam cumi – cumi dan ikan kembung yang ada di TPI Tambak Lorok Semarang, FTIR menunjukkan terdapat polimer plastik jenis nitrile dan nylon. Microplastic is one of the pollutants of the sea. Microplastics do not degrade quickly. Microplastics are plastic particles <5mm in size. Its small size allows it to be transported all over the place including the body systems of fish and squid. The research was conducted to determine the microplastics in squid (Loligo sp.) And mackerel fish (Rastrelliger sp.). The research was conducted in July 2020 - November 2020 in Semarang, Central Java. Sampling was carried out at TPI Tambak Lorok Semarang. Measurements of squid were carried out using a caliper and fish were measured using a ruler. Squid and fish surgery is performed using surgical scissors to separate the digestive organs, tentacles and fish gills that will be used as samples. Dissolving was carried out using 10% KOH immersion for 24 hours to dissolve organic matter. The separation of microplastic particles is carried out after all the organic material in the sample is completely dissolved. The separation of microplastic particles was carried out using ZnCl2 immersion for 24 hours. Filtering of the sample is carried out after the sample has 2 layers, 10 ml of the first layer is taken then filtered using Whatman paper with a vacump pump. The filtered sample was dried, followed by the FTIR test. The results showed that there were microplastics in the squid and mackerel in Tambak Lorok Semarang, FTIR showed that there were plastic polymers of nitrile and nylon types.

Oxidative Stress Is Involved In The Activation of NF-κB Signal Pathway And Immune Inflammatory Response In Grass Carp Gill Induced By Cypermethrin And/Or Sulfamethoxazole Exposure

At present, the concentration of environmental pollutants, such as pesticides and antibiotics exposed in environment, especially in aquatic environment is increasing. These contaminants are exposed through aquatic environment to fish and ultimately accumulate in humans. Research on environmental pollutants has exploded in the past two years. However, there are still few studies on the combined effects of pesticides and antibiotics on fish, especially on fish gills. A separate analysis of the toxic effects caused by an environmental pollutant cannot fully show the real situation. In this paper, cypermethrin (CMN) and sulfamethoxazole (SMZ) were analyzed and found that there was a strong correlation between the pathways affected by the first 30 genes regulated by CMN and SMZ respectively. Therefore, the toxic effects of CMN (0.651 μg/L) and/or SMZ (0.3 μg/L) on grass carp gill were studied in this paper. Histopathology, quantitative real-time PCR and other methods were used to detect the tissue morphology, oxidative stress level, inflammation and apoptosis-related indicators of the fish gills after exposure 42 days. It was found that compared with the single exposure (SMZ/CMN) group, the combined exposure (MIX) group had a more pronounced oxidative stress index imbalance. At the same time, nuclear factor-κB (NF-κB) signal pathway was activated and immuno-inflammatory reaction appeared in MIX group. This study reveals the harm of CMN and SMZ to fish, and provides a reference and basis for the rational use of pesticides and antibiotics.

Iron and Potassium Fertilization Improve Rocket Growth without Affecting Tilapia Growth and Histomorphology Characteristics in Aquaponics

Aquaponics provides an alternative opportunity for the combined production of fish and plants. Most of the essential nutrients required for optimal plant growth can be supplied from the fish feed, except for K and Fe. These nutrients are usually inadequate in fish feed. In this study, red tilapia and rocket plants were co-cultivated in an aquaponics system along with the extra addition of K and Fe. Fish growth, morpho-anatomical characteristics, and K and Fe loading on fish gills were studied. Plant growth parameters were also determined. The addition of Fe and K slightly improved the produced fresh biomass of rocket per unit area and had no impact on tilapia growth and survival. No severe histological alterations in fish gills, liver, and midgut were detected. EDX analysis showed that the addition of K led to the enrichment of this specific ion in fish gills, but no effects of this accumulation were found on other aspects of fish growth and survival.

BILLINGS RESERVOIR (BRAZIL): CHEMICAL STUDIES ON WATER AND CHEMICAL AND MORPHOLOGICAL STUDIES ON ZEBRAFISH GILLS

Previous study of this research group revealed that water from the Billings reservoir (Brazil) intended for human use (water supply and seafood) has microbiological contamination and causes lethality and brain and behavioral impairments in zebrafish. The objective of this study was to understand what have induced these impairments in the animal model. Chemical analyses on water samples from Rio Pequeno (RP), Rio Grande (RG), and Bororé (BO) rivers, as well as chemical and morphological analyses on zebrafish gills exposed to those waters were performed. Waters samples from RP, RG, and BO presented high levels of phosphorus. BO water and fish gills exposed to this water presented high levels of nitrogen. RG water caused potassium contamination in gills. Phosphorus, nitrogen, and potassium are indicators of anthropogenic pollution. RG water and fish gills exposed to this water presented low levels of calcium, which might be an indication of chemical imbalance that could lead to health problems in aquatic animals. RG and BO waters resulted in zirconium contamination in gills. BO water induced respiratory lamellae thickening in the gills, which may be the underlying mechanism for the observed hypoxia. In conclusion, behavioral, brain, and respiratory defects observed previously were induced by chemical and morphologicalb disturbances due to anthropogenic pollution in the Billings reservoir.