Search results for "Anodonta"
showing 10 items of 25 documents
Increased Parasite Abundance Associated with Reproductive Maturity of the Clam Anodonta piscinalis
1999
Several studies on vertebrates have demonstrated that reproductive activities may increase the parasite load, but this has not been shown in invertebrate hosts. We studied abundance of a potentially harmful gill parasite, the ergasilid copepod Paraergasilus rylovi, from the freshwater bivalve host Anodonta piscinalis in relation to reproductive maturity of the host in the field. Prevalence of this previously unstudied parasite varied from 90 to 100%, and the mean parasite abundance from 16.3 to 28.8 among 3 study populations. Abundance of P. rylovi increased with host size. In the maturating age groups (3-5 yr) the length-adjusted mean parasite abundance among mature, reproducing female cla…
Bioaccumulation, bioavailability and environmental fate of chlorophenol impurities, polychlorinated hydroxydiphenylethers and their methoxy analogues.
2006
The bioaccumulation potential and environmental fate of polychlorinated hydroxydiphenyl ethers (HO-PCDEs; polychlorinated phenoxyphenols, PCPP), the major impurities of chlorophenol formulations and their methoxy analogues (MeO-PCDEs; polychlorinated methoxyanisoles, PCPAs) were investigated. Oligochaete worms (Lumbriculus variegatus) exposed to sediment spiked with a model substance of one HO-hexaCDE (4'-HO-PCDE 161) or its methoxy analogue (4'-MeO-PCDE 161) clearly accumulated the test compounds revealing the potential for environmental risk of HO-PCDEs and MeO-PCDEs. The HO-PCDE tested has earlier been reported as an abundant component in a Finnish chlorophenol formulation (Ky-5) and its…
ASPECTS OF THE ECOLOGY AND NATURAL HISTORY OF PARAERGASILUS RYLOVI (COPEPODA, ERGASILIDAE) PARASITIC IN UNIONIDS OF FINLAND
2004
The distribution of Paraergasilus rylovi in 17 populations of unionids was investigated. In 1 unionid population, the parasite was studied regarding host age, size, sex, and the reproductive period (occurrence of egg sacs). Results from pooled material from the years 1987--1989 and 1996 (southern Finland, 11 populations) indicated that Anodonta piscinalis (n = 1,359) is the main host (total mean prevalence 71% and intensity +/-SE of infection 16.4+/-0.6). Pseudanodonta complanata (n = 106) was infected occasionally (3% and 1.3+/-0.3), whereas Unio pictorum (n = 108) and U. tumidus (n = 17) were not infected. Results from 17 A. piscinalis populations showed that P. rylovi occurs in southern …
Trends of organochlorine compounds in Finnish inland waters
2001
Caged common lake mussels (Anodonta piscinalis) have been used in the monitoring of organochlorine compounds in pulp and paper mill recipient watercourses of Finland annually from 1984 to 1998. Statistically significant decreasing trends of chlorophenols and chloroguaiacols originating from chlorobleaching were observed in all recipients in parallel with the decreasing discharges from the mills. Metabolites of chlorophenols, chloroanisoles and chloroveratroles had no or slightly increasing trends. Elevated PCB concentrations were measured in four watercourses. In two areas, PCBs were found to be significantly increasing, in two other cases they showed no trend. A mill producing recycled pap…
Weiteres zum Lichtsinn augenloser Muscheln
1954
The cycless musselsAnodonta cygnea andPseudanodonta complanata do not show any phototaxis. In the “Zweilichterversuch” (two-light-experiment) they react to the decrease of light intensity. If light is increasing, the mussels will not react; if put in the shade, they immediately do so. If the shadow is moved, the mussels even react when the intensity of light decreases much less, which demonstrates the importance of motion. From this it follows that the reception of motion may be considered as possible where there is light sensitiveness of the skin, and where the experiment connects motion with shading.
Organochlorines as Environmental Tainting Substances: Taste Panel Study and Chemical Analyses of Incubated Mussels
1992
Lake mussels (Anodonta piscinalis) incubated in freshwater stations upstream and downstream of a large pulp mill were studied for tainting by a panel of 18 persons. The tasted animal muscle and tissue water samples, and composites of other simultaneously incubated mussels were analyzed for organochlorine compounds. Bad taste scores were obtained for mussels from the nearest station downstream to the pulp mill and were significantly (p < 0.001 **) higher than those from other stations. A similar difference was observed for the measured chlorophenol, chloroanisole and chloroveratrole, chlorocymene and PCB contents. Chloroanisoles and chloroveratroles were indicated to form the main tai…
The joint adverse effects of aged nanoscale plastic debris and their co-occurring benzo[α]pyrene in freshwater mussel (Anodonta anatina)
2021
Although the presence of small-scale plastics, including nanoscale plastic debris (NPD, size1 μm), is expected in the environment, our understanding of their potential uptake and biodistribution in organisms is still limited. This mostly is because of the limitations in analytical techniques to characterize NPD in organisms' bodies. Moreover, it is still debatable whether aged NPD can sorb and transfer chemicals into organisms. Here, we apply iron oxide-doped polystyrene nanoparticles (Fe-PS NPs) of 270 nm size to quantify the uptake and biodistribution of NPD in freshwater mussels (Anodonta anatina). The Fe-PS NPs were, first, oxidized using heat-activated potassium persulfate treatments t…
Crayfish predation on mussels : an experimental approach
2013
Tässä työssä tutkittiin kokeellisesti rapujen simpukoihin kohdistuvaa predaatiota. Käytetyt rapulajit olivat jokirapu Astacus astacus ja amerikkalainen tulokaslaji täplärapu Pascifastacus leniusculus. Jokirapupredaatiota tutkittiin pikkujärvisimpukalla Anodonta anatina ja täplärapupredaatiota pikkujärvisimpukalla sekä jokihelmisimpukalla Margaritifera margaritifera Kokeissa ravut laitettiin yksittäin 15 litran läpivirtausaltaisiin simpukan/simpukoiden kanssa. Täplärapu osoittautui tehokkaammaksi predaattoriksi onnistuen aukaisemaan seitsemän 42:sta Anodontasta. Jokirapu ei saanut avattua yhtään 37:stä Anodontasta. Aukaisemisen ja pehmytosien syömisen lisäksi rapujen havaittiin nakertavan si…
Connection between temperature, larval production, virulence and geographical distribution of Rhipidocotyle parasites infecting the duck mussel, Anod…
2015
In this thesis, two bucephalid trematode parasites Rhipidocotyle campanula and R. fennica, which use the same first (Anodonta anatina) and second intermediate (Rutilus rutilus) host were studied. The aim was to investigate the effect of temperature on one of the key processes in the transmission of these parasites: 1) the emergence of cercarial larvae from A. anatina over short (1 h) and 2) long (throughout the annual cercarial shedding period, from May to October) time periods as well, as on 3) mussel survival and 4) the seasonal timing of cercarial release. In addition, the aim was to study how the cercarial shedding traits are linked to the 5) geographical occurrence and abundance of the…
Long-lasting effect of stress on susceptibility of a freshwater clam to copepod parasitism.
2005
The question whether a stress event can have a long-lasting effect on susceptibility to parasites was studied using a freshwater bivalve clam and its crustacean parasite as a model system. Anodonta piscinalis clams were collected from 2 populations during August–September 2002. Clams were transported to the laboratory and marked. The stressed clams were subjected to low oxygen for 25 days, while the unstressed control clams were caged in their lakes of origin for the same period. Then the clams were transported to a third lake where they were exposed to natural infections by the ergasilid copepod, Paraergasilus rylovi , 11 months after the stress event. The stressed clams were more intensiv…