Effect of diazinon on life stages and resting egg hatchability of rotifer Brachionus plicatilis

Abstract

This paper has not been submitted elsewhere in identical or similar form, not will it be during the first three months after its submission to Hydrobiologia. showed that among the life history parameters, the time the rotifers took to release neonates is the most sensitive, giving the lowest EC 50 value of 1.24 mg/L. The fecundity of maternal females, amictic and mictic daughters was also investigated. Rotifers exposed to 10.0 mg/L produced significantly fewer amictic daughters, and at this concentration, rotifers did not produce any mictic daughter. At 5.0 mg/L, the number of male offspring was significantly lower than the control. Furthermore, the hatchability of resting eggs produced by the rotifers was evaluated when exposed to diazinon: from birth until they produced resting eggs (early development); during late developmental stage of resting eggs (before diapause); and during diapausing stage. The hatchability of the resting eggs was not affected when exposure was timed at late developmental and diapausing stages. Overall results showed that even though amictic females reproduced normally in the presence of low concentration of diazinon, sexual reproduction is severely affected, especially the hatchability of resting eggs when the exposure was timed on its early developmental stages. This provides another evidence that production of resting eggs is particularly sensitive to the presence of xenobiotics in the environment.

Effects of atrazine and carbaryl on growth and reproduction of the rotiferBrachionus calyciflorusPallas

“…This study showed that even though amictic females reproduced normally in the presence of low concentrations of atrazine and carbaryl, viability of resting eggs was severely affected. The vigor of resting eggs of B. plicatilis exposed to low concentrations of diazinon also produced similar results (Marcial and Hagiwara 2007). Thus, the viability of resting eggs is an ecologically key index for assessing effects of pollutants on the reproduction of rotifers and others.…”

“…These results show that sexual reproduction is more sensitive than asexual reproduction when rotifers are exposed to atrazine and carbaryl. Several investigations using the rotifers B. calyciPorus and B. plicatilis also found this phenomenon when rotifers were exposed to pesticides and steroid hormones (Snell and Carmona 1995;Preston et al 2000;Preston and Snell 2001;Marcial and Hagiwara 2007;Snell and DesRosiers-noac 2008). Thus, rotifers may be used as biomarkers for the presence of endocrine-disrupting chemicals in the environment.…”

“…The HR is considered to be the most sensitive parameter for assessing pollutants (Marcial et al 2005;Marcial and Hagiwara 2007). Factors such as light, temperature, salinity, and food concentration affected the HR (Hagiwara et al 1988;Hagiwara and Hino 1989;Gilbert 2010).…”

Effects of Fenvalerate and TBTC (EDCs) on life history characteristics of freshwater rotifer <i>Brachionus calyciflorus</i>

“…储朝霞等对轮虫生活史特征的影响的研究也表明轮虫的胚胎发育时间和幼体阶段会受到草甘 膦的影响 [5] . Marcial等对褶皱臂尾轮虫生活史参数如产第一枚卵的时间和第一枚卵孵化时间、 生殖期以及 平均寿命的研究发现, 当敌匹硫磷的浓度达5mg/L时会延迟其产卵时间, 暴露于2.5mg/L或更高浓度第一 次产幼时间比对照组延迟, 平均寿命也受到影响, 十指臂尾轮虫平均生命跨度、平均寿命都受到铅离子 浓度水平、混浊度以及二者之间相互作用的影响 [7][8] .…”

“…育观察结果相反, 其实验结果认为在褶皱臂尾轮虫各生活史参数中, 第一枚卵的孵化时间(即胚胎发育时 间)最敏感 [8] . 且与对照组比较TBTC的生殖前期历时延长, 即幼体发育阶段延长, 生殖期和生殖后期历时 缩短, 平均寿命也缩短.…”