Noctural Planktonic Behavior of Ranatra montezuma Polhemus (Nepidae: Hemiptera) in Montezuma Well, Arizona
Blinn DW, Pinney C, Sanderson MW. 1982. Noctural Planktonic Behavior of Ranatra montezuma Polhemus (Nepidae: Hemiptera) in Montezuma Well, Arizona. Journal of the Kansas Entomological Society. 55(3):481-484
Ranatra montezuma, a water scorpion endemic to Montezuma Well, displayed a nocturnal planktonic behavior. Horizontal migration from the marginal weed bed into the open water column was initiated at light intensities of <100 lux. Two to three individuals were estimated throughout the open water zone during darkness. Individuals remained within the weed bed at higher light intensities during the day. Average swimming rates of 1.78 cm were measured in the laboratory. The main food item taken in the pelagic region was the planktonic amphipod, Hyalella montezuma, which maintained densities of 25,000 to 32,000 organisms in the top meter of the water column during the night. This is thought to be the first report of a water scorpion exhibiting this unusual nocturnal planktonic behavior.
- Type
- Journal Article
- Authors
- Blinn, Dean; Pinney, Chris; Sanderson, Milton
- Units
- SODN
- Keywords
- Animal Studies, Ground Water, Hydrology, Invertebrates, Water Management