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

İki farklı pestisit (acrolein ve fonofos) maruziyetinin zebra balığında (Danio rerio) kalp gelişimi üzerindeki etkileri

Zebra balığı (Danio rerio), gelişim ve toksikoloji araştırmalarında kullanılan ilgi çekici bir model organizma olmasıyla tanınır. Bu çalışmada, kardiyotoksik etkilerini incelemek üzere zebra balığı embriyoları acrolein (herbisit) ve fonofosa (insektisit) maruz bırakıldı. Gelişimsel toksisite de ayrıca değerlendirildi. Acrolein ve fonofosun 96 saatlik LC50 değerleri sırasıyla 654,385 µg/L ve 7,067 mg/L olarak belirlendi. Daha sonra embriyolara 96 saat boyunca 1, 4, 16, 64, 256 µg/L acrolein ve 0,25, 0,5, 1, 2, 4 mg/L fonofos uygulandı. Embriyolar 48, 72 ve 96. saatlerde incelendi. İki pestisitin de embriyoların gelişimi ile kalbin morfolojisi ve işlevini önemli ölçüde etkilediği gözlendi. Sinüs venozus-bulbus arteriyozus (SV-BA) mesafesinin 64, 256 µg/L acrolein ve 2, 4 mg/L fonofos uygulanan gruplarda kontrollere kıyasla daha uzun olduğu kaydedildi. MF20 antikoru ile immünoboyama, atriyumun açıkça ventrikülün arkasında konumlanmış, yani kalp tüpünde normal kıvrılmanın engellenmiş olduğunu gösterdi. Ayrıca kalp duvarının histolojik yapısında da değişimler belirlendi. 4, 16, 64 ve 256 µg/L uygulamalarında acrolein indüklü artan kalp atım hızı gözlenirken, fonofos yalnızca 4 mg/L'de kalp atım sayısının azalmasına yol açtı. Zebra balığının gelişmekte olan kalbinin acrolein ve fonofos için bir hedef organ olduğu ortaya kondu ve etki mekanizmaları üzerinde daha ileri araştırmalar yapılması gerektiği sonucuna varıldı.Zebrafish (Danio rerio) has a good reputation for being an attractive model organism for developmental and toxicological research. In this study, zebrafish embryos were exposed to acrolein (herbicide) and fonofos (insecticide) to examine the cardiotoxic effects. Developmental toxicity was also evaluated. The 96 h LC50 values of acrolein and fonofos were determined as 654.385 µg/L and 7.067 mg/L, respectively. Then, the embryos were treated with 1, 4, 16, 64, 256 µg/L acrolein and 0.25, 0.5, 1, 2, 4 mg/L fonofos for 96 h. Embryos were examined at 48, 72 and 96 hpf. Both of the pesticides affected the development and cardiac morphology and function of the embryos. Sinus venosus-bulbus arteriosus (SV-BA) distance of 64, 256 µg/L acrolein and 2, 4 mg/L fonofos groups were elongated compared to the control samples. Immunostaining with MF20 antibody exhibited that the atrium positioned clearly posterior to the ventricle which indicated that the cardiac looping was inhibited. Heart wall structure were altered histologically. Acrolein-induced increased heart rate was observed in 4, 16, 64 and 256 µg/L treatment groups while fonofos caused decreased heart rate only at 4 mg/L. In conclusion, developing heart of zebrafish is a target for acrolein and fonofos. However, the certain mechanisms are currently unknown and further studies are required

Pestisit indüklü kardiyak toksisite araştırmalarında zebra balığı (Danio rerio)

Çevresel kirleticiler, karasal ve sucul ekosistemlerde bozulmalara sebep olmalarının yanı sıra pek çok sağlık sorununa da yol açmaktadır. Pestisitler, devamlı kullanımla çevreye yayılan, hareket eden, farklı çevre fazlarında karşılaştıkları hedef dışı organizmalarda biyolojik etki gösteren kirleticiler olarak bilinmektedir. Pestisitlerin kardiyovasküler hastalıklarla da ilişkili oldukları düşünülmektedir. Bu kimyasalların kalpte meydana getirebilecekleri olası etkilerin araştırılmasında laboratuvar çalışmalarının önemi büyüktür. Zebra balığı (Danio rerio), kardiyak toksisite çalışmalarında gerek embriyonik gerekse ergin dönemde araştırıcılara sayısız kolaylık sağlayan bir model organizma olarak kabul edilmektedir. Pestisitlerin kalp üzerindeki toksik etkilerinin ortaya konması ve etki mekanizmalarının araştırılmasında son yıllarda zebra balıkları sıklıkla kullanılmaktadır. Bu derlemede, pestisit maruziyetine bağlı ortaya çıkan kalp anomalilerinin değerlendirilmesinde neden son yıllarda zebra balığının model sistem olarak kabul edildiğine ayrıntıları ile değinilmiştir

Effects of acute triclosan exposure on gill and liver tissues of zebrafish (

Triclosan (TCS) is a broad-spectrum antimicrobial agent found in personal care, household, veterinary, medical, and industrial products. TCS has been detected in soil, sediment, and surface water. In the current work, the effects of acute exposure to TCS on gill and liver tissues of zebrafish were evaluated. Adult zebrafish were treated with sublethal concentrations of TCS (34, 85, and 170 μg/L) for 120 h. Gill and liver samples were removed and embedded in paraffin for histopathological investigations. TCS induced aneurysm, capillary dilation, lamellar disorganization, hyperplasia, epithelial lifting, and desquamation in the gills. Liver specimens showed sinusoidal dilation, congestion, vacuolization, hepatocellular degeneration, and necrosis. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to observe the apoptotic effect of TCS. Accordingly, no apoptotic cells were detected in the specimens of 34 μg/L of TCS exposed gills, while the slides of 85 and 170 μg/L of TCS treated gills showed a high number of TUNEL-positive cells. In the liver, no TUNEL-positive cells were identified in 34 μg/L of TCS treated samples of zebrafish. 85 and 170 μg/L of TCS exposed livers showed few hepatic parenchymal cells undergoing apoptosis.Triclosan (TCS) is a broad-spectrum antimicrobial agent found in personal care, household, veterinary, medical, and industrial products. TCS has been detected in soil, sediment, and surface water. In the current work, the effects of acute exposure to TCS on gill and liver tissues of zebrafish were evaluated and the results indicated that TCS caused distinct histopathological alterations

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

Cardiac toxicity of acrolein exposure in embryonic zebrafish (Danio rerio)

Arman, Sezgi/0000-0002-4247-0639WOS: 000527523900002PubMed: 32307682Acrolein is a widely distributed pollutant produced from various sources such as industrial waste, organic combustion, and power plant emissions. It is also intentionally released into irrigation canals to control invasive aquatic plants. Zebrafish (Danio rerio) has a good reputation for being an attractive model organism for developmental and toxicological research. in this study, zebrafish embryos were exposed to acrolein to investigate the cardiotoxic effects. the 96-h LC50 (median lethal concentration) value of acrolein was determined as 654.385 mu g/L. Then, the embryos were treated with the sublethal experimental concentrations of acrolein (1, 4, 16, 64, and 256 mu g/L) for 96 h. Embryos were examined at 48, 72, and 96 h post-fertilization (hpf). Acrolein affected the cardiac morphology and function of the embryos. Sinus venosus-bulbus arteriosus (SV-BA) distance of 64 mu g/L and 256 mu g/L acrolein groups was elongated compared with the control samples. Immunostaining with MF20 antibody clearly exhibited that the atrium positioned posterior to the ventricle which indicated cardiac looping inhibition. Histological preparations also showed the mispositioning and the lumens of the chambers narrowed. Acrolein-induced increased heart rate was noted in the 4, 16, 64, and 256 mu g/L treatment groups. Taken together, these results indicated that acrolein disrupted the heart development and cardiac function in zebrafish, suggesting that its water-borne risks should be considered seriously