In the literature about the respiratory physiology of water-breathers, the arterial partial pressure of oxygen, P&o2, is reported to range from about 2 to 10-13 kPa (Shelton etal. 1986; McMahon and Wilkens, 1983). In fish, Shelton etal. (1986) reported that animals with low blood O2-affinity exhibit high P a ^ and vice versa. But in laboratory conditions, the excitation state of the animals may...

Freshwater mussels in California's rivers are potentially very useful as indicators of watershed health and recorders of watershed changes. We report the occurrence and habitat of mussel populations within a continuous 8-km section of the South Fork Eel River in the Northern Coast Range of California. The primary goals of our study were 1) to compile information on species composition and popul...

Freshwater mussels are important constituents of freshwater ecosystems, yet much of their basic biology remains to be examined. The behavior of 3 species of unionid mussels (Unio tumidus, Unio pictorum, and Anodonta anatina) was examined in the lowland River Spree (Germany). Mussels were marked individually, and their positions on the sediment surface and depth below the sediment surface were r...

from earlier experiments. Similar results were obtained for the freshwater bivalve Anodonta cygnea (Gade et al., 1975). In this animal, acetate and propionate were responsible for over 75 % of total accumulated end products after 30h of anaerobiosis. As volatile fatty acids can be stored in the animal in esterified form, some of the homogenates obtained in the experiments represented in Table 1...

Cyanobacteria are a potential threat to aquatic ecosystems and human health because of their ability produce cyanotoxins, such as microcystins (MCs). MCs regularly monitored in fresh waters, but rarely estuarine marine waters despite the possibility downstream export. Over period two years, we monthly analyzed intracellular (in phytoplankton) extracellular (dissolved water) at five stations alo...

nowadays, bivalves are used in monitoring levels of heavy metals in aquatic environments. the aim of this study was to investigate bioaccumulation of heavy metals zinc (zn) and chromium (cr) in the internal organs of anodonta cygnea. for this purpose, bivalve specimens were collected from semeskandeh region, sari, and then in laboratory, were exposed to 125 µg l-1 concentrations of each metal f...