Effects of Cadmium and Zinc on the Gamete Viability, Fertilization, and Embryonic Development ofTripneustes gratilla(Linnaeus)

Abstract

Heavy metals are frequently reported for their mutagenic and teratogenic effects on benthic organisms. Thus, this study aimed to determine the toxicity of cadmium (Cd) and zinc (Zn) in the gametes of T. gratilla and to compare its fertilization and embryonic development under the highest nongametotoxic concentrations of these heavy metals. Gamete viability of T. gratilla under CdCl2 and ZnSO4 treatments was assayed through resazurin reduction test (RRT) and was confirmed through gamete morphology assay. ZnSO4 was more toxic to T. gratilla gametes than CdCl2 and egg cells were more sensitive to both than the sperm cells. Higher concentrations of CdCl2 and ZnSO4 induced gamete apoptosis and necrosis while highest nongametotoxic concentrations were determined at 1 × 10−3 M and 1 × 10−4 M, respectively, and were used in an in vitro fertilization and embryonic development experiment. ZnSO4 treatment inhibited fertilization more than CdCl2 and yielded more deformed embryos, while both induced abnormalities and hindered further embryonic development. This study gives the first report on the specific concentrations of Cd and Zn that are toxic to T. gratilla gametes and has confirmed the teratogenic effects of these heavy metals.

Cytotoxicity and Antiangiogenic Activity ofTurbinaria ornataAgardh andPadina australisHauck Ethanolic Extracts

“…The cytotoxicity of T. ornata and P. australis extracts was assayed through the resazurin reduction test (RRT) following the method of Tualla and Bitacura [ 37 ] with slight modification. This test is based on the ability of living cells to reduce the blue resazurin into pink resorufin.…”

Biosorption of Cadmium by Filamentous Fungi Isolated from Coastal Water and Sediments

“…Metal effluents from the metal processing industries that are discharged into water bodies are not biodegraded but undergo chemical or microbial transformations, creating a large impact on the environment and public health [ 1 , 2 ]. Recently, they have been found to be negatively affecting the gamete viability, fertilization, and embryonic development of Tripneustes gratilla , a marine invertebrate model organism [ 3 ]. Awareness of the importance of treatments and removal of heavy metals from such effluents to permissible limits before discharging into natural streams, rivers, and seas is rapidly growing worldwide.…”

Effect of Chlordecone on the Reproductive Potential of the Cichlid Fish, Pseudetroplus Maculatus (Bloch, 1795)

“…Therefore, it is highly susceptible to disturbances caused by the environmental contaminants that include impaired gonadal development, decreased steroidogenesis, testicular impairment, and oxidative stress-induced testicular toxicity [57,58]. Besides, exposure to environmental contaminants has been shown to interfere with the activation of sperm that result in demasculinization, reduced sperm motility, viability and count along with reduction in gametic viability, fertilization potential and embryonic development [59,60,61].…”