Testing the cost of reproduction with the rotifer Brachionus patulus at different pH levels

Abstract

In the present work, we tested the hypothesis that the cost of reproduction was evident under stressful conditions with the rotifer Brachionus patulus at different pH levels (5-10 at 1 unit intervals). We used sublethal pH levels (pH 5, 9, and 10) to simulate stressful conditions. We analyzed the correlations between age-specific fecundity (m 1 , m 2 , m 3 , …) versus future survival (l x ? 1 , l x ? 2 , l x ? 3 , … for the entire lifespan) (survival costs) and future expectation of reproduction. . . for the entire lifespan) (reproductive costs), using the data obtained from life table demographic studies of B. patulus under stressful and favorable (pH 6, 7, and 8) pH levels. The results showed that significant negative correlations were observed between age-specific fecundity and future survival and future expectation of reproduction at all tested pH levels, indicating that costs of reproduction exist in the rotifer B. patulus under stressful and favorable pH conditions. However, the percentage of statistically significant negative correlations from total correlations of survival and reproductive costs differed greatly, depending on the tested pH conditions. The percentage of significant negative correlation of reproductive costs is significantly higher under stressful pH conditions (pH 5, 9, and 10) than favorable pH conditions (pH 6, 7, and 8). For survival costs, the same trends are also observed, suggesting that the costs of reproduction were more obvious under stressful pH than favorable pH.

Aging extension and modifications of lipid metabolism in the monogonont rotifer Brachionus koreanus under chronic caloric restriction

“…The energy trade-off between life span and reproduction is commonly observed in most animal taxa 1 . This phenomenon can be affected by various abiotic and biotic factors, such as temperature 2 , 3 , pH 4 , and metabolic changes 5 . Among them, chronic caloric restriction (CCR) is a well-known regulator leading to an energy trade-off in various organisms such as mice 6 – 8 , the grasshopper Romalea microptera 9 , the nematode Caenorhabditis elegans 10 , and the rotifer Brachionus manjavacas 11 .…”

Male mealworm beetles increase resting metabolic rate under terminal investment

“…An organism's reproductive value is dependent on its current and future reproduction, and the theory predicts that higher investment in current reproduction hinders growth, survival or future reproductive success (Williams, ; Creighton et al ., ; Dao et al ., ; Yin & Niu, ; Bowers et al ., ). When being attacked by harmful parasites severely reducing both future reproductive success and survival, the host may allocate most of its resources in an effort to produce as many offspring as possible in the face of increased probability of death.…”