Effects of stem rotifer body size on morphology, starvation resistance and population growth of offspring in Brachionus calyciflorus

Abstract

The morphological plasticity of rotifers has been investigated for several decades, and the maternal effects as an important source of variation in life history traits of rotifers have been reported. However, little is known in relation to the effects of maternal body size on offspring. In the represent study, resting eggs were collected from three Brachionus calyciflorus strains (A, B and C). From the hatchlings of each strain, the biggest and smallest stem rotifers were collected and named as the large-sized and small-sized morphotypes, respectively. The differences in body size (at 20 °C, 25 °C and 30 °C), starvation resistance and population growth were compared between strains and morphotypes. The results showed that strain and morphotype of maternal rotifers showed more important effects on the body size of offspring than temperature. Large-sized stem rotifers revealed significantly bigger offspring than small-sized stem rotifers, indicating significant maternal effects of body size on the morphology of offspring. At 25 °C, compared with small-sized stem rotifers, the offspring of large-sized stem rotifers showed significantly longer starvation resistance time in strain C and significantly higher population growth rate in strain B. These results demonstrated that strain is an important factor affecting the maternal effects of stem rotifer body size on offspring. Overall, this study provides more information to understand the morphological diversity of rotifers in field environments.