The effects of temperature and oxygen saturation on the respiration rate of two cold stenothermal chironomids, Diamesa insignipes and Pseudodiamesa branickii were investigated. Fourth instar larvae were collected in winter in a glacio-rhithral stream(1300 ma.s.l., Alps, NE-Italy) and their respiration rate was measured with a Clark’s electrode in the range 0–14°C. The respiration rate was significantly higher in D. insignipes than in P. branickii at low temperatures (<=4°C), higher in P. branickii between 8 and 12°C and comparable at 14°C. Higher values of R (regulation value), R25% (respiration rate at 25% oxygen saturation) and b1/b2 (slope ratio in piecewise linear regression), and lower values of Pc (critical pressure) and I (initial decrease) were recorded in P. branickii than in D. insignipes. These values are compatible with oxy-regulatory behaviour in P. branickii, whereas D. insignipes appeared to be almost an oxy-conformer. On the basis of this autoecological information, new implications regarding survival of species from cold, high altitude habitats under changing climatic conditions are made.
Lencioni, V.; Bernabò, P.; Vanin, S.; Di Muro, P.; Beltramini, M. (2008). Respiration rate and oxy-regulatory capacity in cold stenothermal chironomids., 54 (9): 1337-1342. doi: 10.1016/j.jinsphys.2008.07.002
Respiration rate and oxy-regulatory capacity in cold stenothermal chironomids
LENCIONI, VALERIA;
2008-01-01
Abstract
The effects of temperature and oxygen saturation on the respiration rate of two cold stenothermal chironomids, Diamesa insignipes and Pseudodiamesa branickii were investigated. Fourth instar larvae were collected in winter in a glacio-rhithral stream(1300 ma.s.l., Alps, NE-Italy) and their respiration rate was measured with a Clark’s electrode in the range 0–14°C. The respiration rate was significantly higher in D. insignipes than in P. branickii at low temperatures (<=4°C), higher in P. branickii between 8 and 12°C and comparable at 14°C. Higher values of R (regulation value), R25% (respiration rate at 25% oxygen saturation) and b1/b2 (slope ratio in piecewise linear regression), and lower values of Pc (critical pressure) and I (initial decrease) were recorded in P. branickii than in D. insignipes. These values are compatible with oxy-regulatory behaviour in P. branickii, whereas D. insignipes appeared to be almost an oxy-conformer. On the basis of this autoecological information, new implications regarding survival of species from cold, high altitude habitats under changing climatic conditions are made.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
