BIOCHEMICAL EVALUATIONS OF QUINALPHOS EXPOSED ZEBRAFISH LIVER ORGANOTYPIC TISSUE

As being a broad-spectrum, organophosphorus insecticide and acaricide, quinalphos is widely used against a range of pests, and has a great threat on aquatic systems. Although the methods for detecting and predicting of the harmful effects of chemicals on non-target organisms are traditionally perfected by in vivo experiments, cell culture methods that being used widely in recent decades is also an important tool for these kinds of research. In order evaluate the effects of quinalphos on liver organotypic culture system of zebrafish, tissue cubes (1-2 mm3) were prepared by dissection and slicing of liver tissues, embedded in agarose and cultured. The cubes were exposed to three different concentrations of quinalphos (2, 4 and 8 mg/L) for 24 and 96 hours. By performing comet assay as an emerging tool for cytotoxicity, it was detected that quinalphos causes DNA damage. Increased levels of catalase, superoxide dismutase and glutathione-s-transferase were also measured. All of these parameters were noted as concentration- and time-dependent. Our data suggest that organotypic liver tissue culture of zebrafish is a practical alternative to whole fish

Gonadal histology of the tiger barb Puntius tetrazona (Cyprinidae)

The ornamental fish industry constitutes a big portion of the economy in many countries of the world. Thousands of attractive fish species are traded annually. The tiger barb Puntius tetrazona is one of the most charming freshwater aquarium species worldwide. The present paper aimed at expanding the knowledge of the reproductive biology of this tropical fish. The ovary and the testis tissues of the tiger barb were embedded in paraffin following routine histological processes, stained with hematoxylin and eosin and Mallory’s trichrome techniques, and investigated by light microscopy. Histological examinations confirmed asynchronous-type ovaries resembling four different developmental stages including primary growth, cortical alveolar, vitellogenic and maturation. In the testis, primary spermatogonia, secondary spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa were identified. All oogenetic and spermatogenetic phases and mature germ cells occurred simultaneously in the tiger barb. This feature allows this tropical fish to breed rapidly and helps expanding its global trades

Oocyte development in the Zebrafish, Danio rerio (Teleostei: Cyprinidae)

Oocyte development in the ovary of zebrafish were investigated by light microscopy and four main developmental stages differentiated according to their histological properties were identified as primary oocyte stage, cortical-alveolar stage, vitellogenic stage, and maturation.Zebra balığında Danio rerio’da (Teleostei: Cyprinidae) oosit gelişimi. Zebra balığı ovaryumlarında oosit gelişimi ışık mikroskobu ile araştırılmış ve histolojik özelliklere göre ayırt edilen dört esas gelişim aşaması; primer oosit evresi, kortikal alveolar evre, vitellojenik evre ve olgunluk evresi olarak tanımlanmıştır

Impact of acute fonofos exposure on skeletal muscle of zebrafish: Histopathological and biometric analyses

It is widely known that pesticides generally do not show target specificity, and off-target species are strikingly affected by these chemicals. In the current work, histological changes in skeletal muscles of zebrafish (Danio rerio) caused by fonofos, an acetylcholinesterase (AChE) inhibitor organophosphate insecticide, were examined. Zebrafish were treated with 1 mg/L, 2 mg/L and 4 mg/L of fonofos for 96 hours. Skeletal muscle samples were removed from the pectoral region and embedded in paraffin. Sections were stained with Mayer's Hematoxylin and Eosin, Gomori's Trichrome and Periodic Acid Schiff techniques. Histopathological alterations were investigated by light microscopy. Fibrosis, intramyofibrillar vacuoles, disintegrated myofibrils, splitting of myofibers, atrophic and disappeared fibers, histoarchitectural loss, necrosis and progressive decrement in glycogen content were noted. Muscle fiber diameter measurements were also performed. Statistical analysis showed that measured fiber diameters of all fonofos exposed groups were significantly different from the control group, and they decreased in a concentration-dependent manner. These results suggested that fonofos caused significant myoarchitectural impairments in non-target freshwater zebrafish.The present work investigated histological changes in skeletal muscles of zebrafish (Danio rerio) caused by fonofos, an organophosphate insecticide. Fonofos-induced fibrosis, intramyofibrillar vacuoles, disintegrated myofibrils, splitting of myofibers, atrophic and disappeared fibers, histoarchitectural loss, necrosis and progressive decrement in glycogen content were noted. Muscle fiber diameter measurements showed that the fiber diameters of all fonofos exposed groups were decreased in a concentration-dependent manner. These results suggested that fonofos caused significant myoarchitectural impairments in non-target freshwater zebrafish