Observations on the Ecology of the Freshwater Jellyfish in Lake Mead, Nevada
Deacon JE and Haskell WL. 1967. Observations on the Ecology of the Freshwater Jellyfish in Lake Mead, Nevada. The American Midland Naturalist. 78(1):155-166
Observations and collections of Craspedacusta sowerbyi Lankester occurred at approximately one-week intervals from Oct 25, 1962 to Jan 25, 1963 in Lake Mead, Nevada. The medusa population was most concentrated in deeper wtaer in the morning. Vertical distribution became nearly uniform by midafternoon. Numbers of medusa at the survace were very low at night and increased rapidy after the sun struck the water surface. Laboratory observations indicate an attraction to light as distinct from a stimulation to activity by light. Females were always more abundant than males. Medusae first appeared in the lake in June, 1962, becoming abundant in late September, and disappearing at the end of January, 1963. Above average water temperatures and a rapid rise in water level to an unusually high level are correlated with the development of the medusae population.
- Type
- Journal Article
- Authors
- Deacon, James; Haskell, W
- Units
- LAKE
- Keywords
- Aquatic Resources, Colorado Plateau, Distribution, Ecology, environmental gradient, Freshwater, Invertebrates (Invertebrata), jellyfish (Craspedacusta sowerbyi Lankester), medusae, Population, Taxa Links To References, vertical migration, Water Level, Water Level Fluctuations