Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to detect the possible presence of these substances in drinking water, aiming to define the most relevant parameters to detect these substances, which particularly affect the development and reproduction of zebrafish. To this end, batches of 30 embryos with the chorion intact were cultured in drinking waters from different sources, throughout their full life-cycle up to 5 months, in 20 L tanks. Six replicates were performed in all water groups, with a total of 24 aquariums. Two generations (F0 and F1) were studied and the following parameters were tested: in the F0 generation, survival and abnormality rates evaluated at 5 dpf (days post fertilization) and at 5 mpf (months post fertilization), the onset of spawning and the fertility rate from 3 mpf to 5 mpf, and the sex ratio and underdeveloped specimens at 5 mpf. Furthermore, in the F0 offspring (F1), survival and abnormality rates were evaluated at 5 dpf and the hatching rate at 72 hpf. These results revealed that the hatching rate is the most sensitive parameter to distinguish different levels of effects between waters during the early life stages, whereas the rate of underdeveloped specimens is more suitable at later life stages. Regarding adult reproduction, fertility rate was the most sensitive parameter. The possible reversibility or accumulative nature of such effects will be studied in future work.

Cambridge University Press (CUP)Martínez-Sales, MI.; García Ximenez, F.; Espinos Gutierrez, FJ. (2015). According to the most sensitive parameters (hatching rate, fertility rate and 32 underdeveloped specimens) detected in our previous work, in the current work we 33 attempt to study, in these parameters, the possible cumulative effect of Results in water C revealed a non-reversible effect on fertility rate, and also in water 44C an alteration of sex ratio towards females, although in this case the alteration was

Organic pollutants are present in drinking waters due to inefficient detection and removal treatments. For this reason, zebrafish is proposed as a complementary indicator in conventional potabilization treatments. Based on the most sensitive parameters detected in our previous work, in this study we attempted to examine the possible cumulative effect between generations of environmental pollutants likely present in drinking waters, when specimens were cultured in the same water and/or the possible reversibility of these effects when cultured in control water. To this end, embryos with the chorion intact were cultured in three drinking waters from different sources and in one control water for up to 5 months in 20 l glass tanks. Four replicates were performed in all water groups. Results in water group C (tap water from a city also located in a region with intensive agricultural activity, but from the hydrological basin of the river Xúquer) revealed a non-reversible effect on fertility rate. Also in water C there was an alteration of sex ratio towards females, although in this case the alteration was reversible. A transgenerational alteration in the germ-line via an epigenetic mechanism from the previous generation is proposed as the most plausible explanation of this effect.

Cambridge University Press (CUP)Martínez-Sales, MI.; García Ximenez, F.; Espinos Gutierrez, FJ. (2016). Discrimination of the effects on zebrafish reproduction from pollutans in drinking water via female , via male and/or via fecundation water. Zygote. 24(4):563-567.