The hemoglobin concentration of Chironomus Cf. plumosus L. (Diptera: Chironomidae) larvae from two lentic habitats

... In the context of the present study, it is worth noting that water temperature and dissolved oxygen content have a great influence on the metabolism of aquatic insects, including chironomids (Rasmussen, 1996; Chapman, 1998; Corbi and Trivinho-Strixino, 2006; Jurenka, 2015). In turn, the oxygen needed to fulfill the metabolic requirements of chironomids is stored by the hemoglobin present in tissues (Lankester, 1867; Walshe, 1947; Panis et al., 1995; Rasmussen, 1996); therefore, changes in insect metabolism induced by increasing water temperature or changes in dissolved oxygen content can be evaluated using alternative indicators such as hemoglobin and its metabolite bilirubin. Similarly, changes in ventilation and locomotor behavior in insects can be evaluated through cholinesterase activity (Jensen et al., 1997; AzevedoPereira et al., 2011). ...

... Indeed, an increased rate of oxygen consumption to support larval development and growth at increasing temperatures probably occurred. In fact, hemoglobin is known to have a comparatively high affinity for O 2 and to be widely distributed in tissues of chironomids, including those of the genus Tanytarsus (Lankester, 1867; Walshe, 1947; Panis et al., 1995; Rasmussen, 1996). The increased levels of dissolved oxygen content observed in Lake Magadi waters between 13:00 h and 19:00 h would enhance the O 2 gradient between the environment and hemoglobin in the larvae, thus ensuring the diffusion of adequate amounts of O 2 into the chironomid larvae. ...

... In the context of the present study, it is worth noting that water temperature and dissolved oxygen content have a great influence on the metabolism of aquatic insects, including chironomids (Rasmussen, 1996; Chapman, 1998; Corbi and Trivinho-Strixino, 2006; Jurenka, 2015). In turn, the oxygen needed to fulfill the metabolic requirements of chironomids is stored by the hemoglobin present in tissues (Lankester, 1867; Walshe, 1947; Panis et al., 1995; Rasmussen, 1996). Therefore, changes in insect metabolism induced by increasing water temperature or changes in dissolved oxygen content can be evaluated using alternative indicators such as hemoglobin and its metabolite bilirubin. ...

... Indeed, an increased rate of oxygen consumption to support larval development and growth at increasing temperatures probably occurred. In fact, hemoglobin is known to have a comparatively high affinity for O2 and to be widely distributed in tissues of chironomids, including those of the genus Tanytarsus (Lankester, 1867; Walshe, 1947; Panis et al., 1995; Rasmussen, 1996). The increased levels of dissolved oxygen content observed in Lake Magadi waters between 1:00 pm and 7:00 pm would enhance the O2 gradient between the environment and hemoglobin in the larvae, thus ensuring the diffusion of adequate amounts of O2 into the chironomid larvae. ...

... In both series of experiments, biomarker concentration was detected after 0 (control), 10, 14, 18, 24 and 48 h on survived larvae. Hemolymph Hb concentration was measured in single alive larvae using the cyano-methemoglobin procedure (Tentori and Salvati, 1981; Int Panis et al., 1995). The larva was placed in 150 μL of saline solution (10 mM potassium phosphate buffer pH 7.4, containing 0.6% NaCl) in a concave glass leaning on ice. ...

... This method was found to be reproducible and accurate. Lyophilization (freeze-drying) of the larvae prior to the analysis is not necessary and may produce anomalous results (IntPanis et al., 1994b). Hemoglobin determinations were carried out on individual defrosted specimens with a wet weight of more than 2 mg (IntPanis et al., 1996). ...

... Similarly, Poulton and Allert (2012) found that Chironomus were among the most dominant midge taxa at oxygen-poor dike pool sites on the lower Missouri River. This genus is particularly effective at colonizing new aquatic habitats by extending the emergence period during summer (Cantrell and McLachlan, 1977) and utilizing hemoglobin to temporarily store oxygen in the blood (Panis et al., 1995) allowing these species to survive periods of low dissolved oxygen that often occur in newly-flooded habitats (Cantrell and McLachlan, 1977). As high water persisted, Baltimore and Dalbey experienced declines in chironomid larvae density as Chironomus numbers declined. ...

... There are various likely explanations for the peculiar variance of stoichiometric ratios among the studied profundal chironomid taxa. The chironomid taxa inhabiting eutrophic sites, C. plumosus in particular, are adapted to oxygen-poor conditions partly due to high haemoglobin concentration (Weber, 1980; Int Panis et al., 1995), whereas the taxa generally considered intolerant to anoxia (Orthocladiinae) are largely lacking haemoglobin (Cranston, 1988). Varying concentrations of nitrogen-rich haemoglobin protein might thus result in the correlations between trophic preference of chironomid taxa and both N content and C:N ratio, but not with P. ...

... This method was found to be reproducible and accurate. Lyophilization (freeze-drying) of the larvae prior to the analysis is not necessary and may produce anomalous results (Int Panis et al., 1994b). All hemoglobin determinations were, therefore, carried out on individual defrosted specimens with a wet weight of more than 2 mg except for Ablabesmyia for which a pooled sample of 10 individuals was used. ...

... There is a difference between the hemoglobin concentrations of the littoral and profundal populations of Chironomus cf. plumosus (Int Panis et al., 1994b) . There-fore, we have not attempted to determine an average hemoglobin concentration for this species. ...

... They were also unable to demonstrate a developmental increase in the hemoglobin concentration of Chironomus anthracinus. It is possible that this is due to methodological differences (Int Panis et al., 1994b) . ...