Energy metabolism of Chironomus anthracinus (Diptera: Chironomidae) from the profundal zone of Lake Esrom, Denmark, as a function of body size, temperature and oxygen concentration

Abstract

The profundal zone of Lake Esrom, Denmark has a dense population of Chironomus anthracinus, which survives 2-4 months of oxygen depletion each summer during stratification . The metabolism of 3rd and 4th instar larvae was examined in regard to variation in biomass and temperature . Respiration at air saturation was described by a curvilinear multiple regression relating oxygen consumption to individual AFDW and temperature . At 10 °C and varying oxygen regimes the 02 consumption and CO2 production of 4th instar larvae were almost unaltered from saturation to about 3 mg 02 1 -l , but decreased steeply below this level . The respiratory quotient increased from 0 .82 at saturation to about 3 .4 at oxygen concentrations near 0 .5 mg 02 1 -1 . This implied a shift from aerobic to partially anaerobic metabolism . At 0 .5 mg 021 -1 the total energy production equalled 20% of the rate at saturation of which more than one third was accounted for by anaerobic degradation of glycogen . This corresponded to a daily loss of 12 pg mg AFDW -1 or approximately 5% of the body reserves . At unchanged metabolic rate the glycogen store would last three weeks, but long term oxygen deficiency causes a further suppression of the energy metabolism in C. anthracinus . 43

Hypoxia and anoxia effects on alcohol dehydrogenase activity and hemoglobin content in Chironomus riparius Meigen, 1804

“…The respiratory rate (R) trend we measured is in accordance with that one observed by Hamburger et al (1994) and Brodersen et al (2008) in other Chironomini such as C. anthracinus, C. riparius and C. hyperboreus Staeger 1845. Nevertheless a slight (not significant) increase in the first hours of treatment resembling typical a oxy-stressor, R remained constant within the first 24 h of treatment with a significant decrease only below 50% of oxygen saturation suggesting for C. riparius larvae from the Rio Gola a oxy-regulator behaviour (i.e., it regulates and maintains a constant R within a % saturation interval) (Brodersen et al, 2008).…”

“…larvae is covered by the alcoholic fermentation of glycogen stores to ethanol (Scholz and Zerbst-Boroffka, 1998). Hamburger et al (1994) reported that anaerobic metabolism represents from 3 (at 3 mgO 2 L -1 ) to 40% (at 0.5 mgO 2 L -1 ) of total energy production in Chironomus larvae (C. anthracinus can regulate its respiratory metabolism down to 2-3 mgO 2 L -1 ). Choi et al (2001) reported that at 1.6 mgO 2 L -1 a switch from aerobic to partial anaerobic metabolism occurred after 48 h of treatment.…”

“…Within the family Chironomidae, a wide range of tolerance to hypoxia/anoxia is displayed. In particular, the genus Chironomus (subfamily Chironominae, tribe Chironomini) is very tolerant towards low levels of dissolved oxygen (Frank, 1983;Hamburger et al, 1994;Marziali et al, 2006). Larvae inhabit the sediment of pools, profundal and sublittoral zones of lakes and river bottoms where they dwell in tubes and feed on detritus, encountering hypoxia or even anoxia (Jó-nasson, 1978;Saether, 1979).…”

Effects of oxygen deficiency on survival and glycogen content of Chironomus anthracinus (Diptera, Chironomidae) under laboratory and field conditions

“…Short term studies have shown that the respiratory metabolism declines sharply below this level but is accompanied by increased anaerobic degradation of glycogen . The compensation for the loss in aerobic metabolism by anaerobic processes, however, is extremely small (Berg et al, 1962 ;Bairlein, 1989 ;Hamburger et al, 1994) .…”

O fenômeno da "decoada" no Pantanal do rio Paraguai, Corumbá/MS: alterações dos parâmetros limnológicos e efeitos sobre os macroinvertebrados bentônicos

“…Determinados gêneros apresentam adaptações que lhes permitem suportar condições de hipoxia e até de anóxia (HECKMAN, 1998;HAMBURGER et al, 1994). No entanto, mesmo representantes de tais gêneros acabam não suportando as baixas tensões de oxigênio se estas condições persistirem por muitos dias, como ocorre na "decoada".…”