The Daily Bulletin Archive

Please join the Biology Department and the Great Lakes Center for their final fall 2018 seminar, "Daphnia's Challenge: Strategies to Survive and Reproduce under Limiting Environmental Conditions," presented by Alicia Perez-Fuentetaja, professor of biology and research scientist with the Great Lakes Center at Buffalo State, today, December 3, from 3:00 to 4:15 p.m. in Bulger Communication Center 424.  

Abstract
Calcium levels have declined in boreal lakes in North America and Europe because of soil mineral leaching, logging, and climate change. Crustacean zooplankton species with a high-calcium demand, such as Daphnia, are particularly vulnerable to calcium-related stress. In a factorial design, we tested the effects of three calcium concentrations and two food levels on second-generation calcium-stressed Daphnia pulex × pulicaria. Calcium limitation affected reproduction, molting, and population growth, but food quantity was also relevant on how Daphnia dealt with the lack of calcium. When adequate levels of calcium were available, population growth was similar in both high and low food conditions; however, under high food but low calcium, Daphnia’s life history strategy was focused on reproduction, and this had a negative effect on survivorship due to calcium limitation. Alternatively, under low food and low calcium, their strategy was on survival and somatic maintenance, minimizing reproduction. Boreal lakes with modest levels of calcium may support Daphnia populations during periods with sufficient food, but if the food quantity or quality is too low to mitigate the effects of calcium limitation, Daphnia populations could disappear because of low reproductive output.