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| Ecology and Behavior | |||||||||||||||||||
| Characteristics | |||||||||||||||||||
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| Geographic Distribution | |||||||||||||||||||
Epischura lacustris was found in, but not limited to, New England (1)( 3)( 4), New York (2)(6), and Canada (3). | |||||||||||||||||||
Habitats |
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| E. lacustris was found in the pelagic zone of cool water lakes (2). | |||||||||||||||||||
| Food and Feeding Behavior | |||||||||||||||||||
E. lacustris is omnivorous, and displays a swim and forage behavior while feeding (1). Adult feeding ranges from highly herbivorous to highly carnivorous, but animals can survive solely on either feeding strategy (1). Copepodite stages are exclusively herbivorous (1). E. lacustris feeds by filtration, preferring large, gelatinous, colonial phytoplankton (5). Adults commonly eat the phytoplankton, Cryptomonas erosa (1). Grazing rates may change seasonally due to abundance of phytoplankton (1). Carnivorous E. lacustris may prey upon rotifers (e.g. Euchlanis dilatata ), and Artemia spp. (brine shrimp). E. lacustris will cannibalize their own eggs and nauplii; they prey upon other copepods, such as Leptodiaptomous sicilis, consuming the entire body (1). |
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| Reproductive Habits | |||||||||||||||||||
| Consumption of rotifers and algae is essential for E. lacustris to sustain reproduction (1). Average clutch size is approximately 10 eggs (1). Egg development may occur over a temperature range of 15-30 ° C, but it is more successful at 15 ° C (2). E gg production is highest (about a dozen per clutch) in the spring, when primary production is at its peak; by late fall egg production is minimal with a shift to diapause eggs (1)(2). E. lacustris stops egg production by early autumn (1). | |||||||||||||||||||
| Predation | |||||||||||||||||||
| Survival from predation, is highest in the spring and lower later in the year (1). Planktivorous fish, such as the pumpkinseed sunfish ( Lepomis gibbosus ) are predators on E. lacustris (4). Adult copepods employ predator avoidance mechanisms such as reduced activity or active escape responses (3). | |||||||||||||||||||
| Migration | |||||||||||||||||||
| E. lacustris displays diel vertical migration and also occur in horizontal patches (1)(5). | |||||||||||||||||||
| Seasonal Variations | |||||||||||||||||||
| Fall warming affects survival and over-wintering of diapause eggs (3). Trends in predation change seasonally, depending on the size of prey and the abundance of available prey (6). The abundance of E. lacustris is influenced by strength of predation which decreases from early spring to summer (6) . | |||||||||||||||||||
| References | |||||||||||||||||||
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(1) Schulze , P.C. and C.L. Folt . 1990. Food resources, survivorship, and reproduction of the omnivorous Calanoid Copepod Epischura lacustris . Ecology. 71: 2224-2240. (2) Confer , J.L. and P.I. Blades . 1975. Omnivorous zooplankton and planktivorous fish. Limnol. Oceanogr. 20: 571-579. (3) Chen , C.Y and C.L Folt . 1996. Consequences of Fall warming for zooplankton overwintering success. Limnol. Oceanogr. 41: 1077-1086. (4) Schulze , P.C. and C.L. Folt . 1989. Effects of conspecifics and phytoplankton on predation rates of the Omnivorous Copepods Epischura lacustris and Epischura nordenskioldi . Limnol. Oceanogr. 34: 444-450. (5) Lane , P.A. 1975. The dynamics of aquatic systems: A comparative study of the structure of four zooplankton communities. Ecol. Monograph. 45: 307-336.
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| Barcode: Ribosomal DNA-28S D3 expansion segment | |||||||||||||||||||
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