TY - JOUR
T1 - Effects of temperature on growth rate and behavior of Epeorus albertae (Ephemeroptera: Heptageniidae) nymphs
AU - Scherr, Melissa A.
AU - Wooster, David E.
AU - Rao, Sujaya
PY - 2010/12
Y1 - 2010/12
N2 - Anthropogenic disturbances affect temperature in river systems. Temperature potentially affects life histories of macroinvertebrates and alters behavior and biological functions. Temperature preferences and tolerance ranges for key taxa are therefore critical for understanding impacts of human-induced changes to water temperatures on river ecosystems. The objective of this study was to examine the effect of water temperature on growth rate and behavior of Epeorus albertae (McDunnough) nymphs. Nymphs were collected from the Umatilla River in eastern Oregon, and exposed to temperatures of 18, 22, and 28°C. Nymphs held at 28°C exhibited increased growth rates compared with individuals held at 18 and 22°C. However, at 28°C the accumulation of nymphal tissues was not consistent with that of nymphs held in lower temperatures; ratios of head capsule width to total body length were significantly lower in individuals at 28°C compared with those held at the lower temperatures. This indicates that the nymphs held at the high temperature had longer total body length relative to the developmental stage, represented by head capsule width, when compared with insects in cooler temperatures. To examine the effect of water temperature on behavior, active drift of mayflies was examined in experimental chambers held at 12, 18, 22, and 28°C. The number of drifting insects observed was significantly higher at 28°C compared with 22, 18, and 12°C. These results indicate that temperature is a factor influencing growth and behavior of E. albertae and is likely to lead to limitations in habitat use of this mayfly.
AB - Anthropogenic disturbances affect temperature in river systems. Temperature potentially affects life histories of macroinvertebrates and alters behavior and biological functions. Temperature preferences and tolerance ranges for key taxa are therefore critical for understanding impacts of human-induced changes to water temperatures on river ecosystems. The objective of this study was to examine the effect of water temperature on growth rate and behavior of Epeorus albertae (McDunnough) nymphs. Nymphs were collected from the Umatilla River in eastern Oregon, and exposed to temperatures of 18, 22, and 28°C. Nymphs held at 28°C exhibited increased growth rates compared with individuals held at 18 and 22°C. However, at 28°C the accumulation of nymphal tissues was not consistent with that of nymphs held in lower temperatures; ratios of head capsule width to total body length were significantly lower in individuals at 28°C compared with those held at the lower temperatures. This indicates that the nymphs held at the high temperature had longer total body length relative to the developmental stage, represented by head capsule width, when compared with insects in cooler temperatures. To examine the effect of water temperature on behavior, active drift of mayflies was examined in experimental chambers held at 12, 18, 22, and 28°C. The number of drifting insects observed was significantly higher at 28°C compared with 22, 18, and 12°C. These results indicate that temperature is a factor influencing growth and behavior of E. albertae and is likely to lead to limitations in habitat use of this mayfly.
KW - Temperature
KW - drift behavior
KW - growth rate
UR - http://www.scopus.com/inward/record.url?scp=79251475606&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79251475606&partnerID=8YFLogxK
U2 - 10.1603/EN09247
DO - 10.1603/EN09247
M3 - Article
C2 - 22182569
AN - SCOPUS:79251475606
SN - 0046-225X
VL - 39
SP - 2017
EP - 2024
JO - Environmental entomology
JF - Environmental entomology
IS - 6
ER -