Optimizing Daphnia magna culturing for management at Lake Waramaug, CT by experimenting with a variety of food sources
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Authors
Rodriguez-Hernandez, Maria
Issue Date
2024-12
Item Type
Thesis
Language
en_US
Keyword
Alternative Title
Abstract
Large-bodied Cladocera such as Daphnia are believed to affect algae and cyanobacteria
populations in Lake Waramaug. The Lake Waramaug Task Force sought to increase the
population of large-bodied Cladocera that had historically been greatly reduced due to the
introduction of landlocked Alosa pseudoharengus (alewife). The goal of this project was to
develop optimal practices for raising Daphnia magna by investigating the effects of different
food sources on fecundity. The experimental food sources were Chlorella vulgaris, Scenedesmus
spp., and a combination of all three food sources (C.v., S. spp., YCT). Preliminary work during
the summers of 2021 & 2022 on the Lake Waramaug zooplankton farm suggested that current
culturing methodology resulted in approximately one organism per liter. A healthy population
should be closer to 10 per liter (B. Kortman personal communication, January 17, 2019). Our
objective was to develop a reliable practice that would result in >1 Daphnia per liter. The food
source that yielded the highest number of neonates and adults was the combination of
YCT/Scenedesmus/Chlorella vulgaris. Additionally, Scenedesmus alone yielded more neonates
compared to YCT or Chlorella vulgaris alone. Since Scenedesmus is twice the size of Chlorella
vulgaris, this additional mass of food could have contributed to these results. This project has
lake management value because it aids in the development of an optimal practice for raising
Daphnia magna populations in a lake where large bodied Cladocera were eradicated due to the
introduction of land-locked alewife.