scholarly journals Immobilization of Daphnia magna and Pesticides Pollution in River Water in Tokyo

2003 ◽  
Vol 13 (2) ◽  
pp. 385-396 ◽  
Author(s):  
Mikio KIKUCHI ◽  
Yuko SASAKI ◽  
Meiko WAKABAYASHI
Keyword(s):  
River Water ◽  
Daphnia Magna

Impacts of Fenholloway River Water on Invertebrate Biodiversity and Growth of Daphnia magna

2003 ◽  
Vol 71 (3) ◽  
pp. 512-519
Author(s):  
T. R. Kozel ◽  
S. C. Pruitt ◽  
W. S. Baldwin ◽  
J. M. Brynda
Keyword(s):  
River Water ◽  
Daphnia Magna ◽  
Invertebrate Biodiversity

Acute Toxicity Assays Using Danio Rerio and Daphnia Magna To Assess Hot-Spring Drainage in The Shibukuro and Tama Rivers (Akita, Japan)

2021 ◽  
Author(s):  
Kyo Suwa ◽  
Chiho Takahashi ◽  
Yoshifumi Horie
Keyword(s):  
River Water ◽  
Daphnia Magna ◽  
Danio Rerio ◽  
Hot Spring ◽  
Aquatic Organisms ◽  
Spring Water ◽  
Water Flea ◽  
Heavy Metal Concentrations ◽  
Negative Effect ◽  
Akita Prefecture

Abstract We investigated the lethal toxicity of Shibukuro and Tama river water near the inflow of Tamagawa hot-spring water in Akita Prefecture, Japan. We first measured heavy metal concentrations in both rivers. We detected iron, arsenic, and aluminum; the concentrations of each tended to decrease from upstream to downstream. We next examined the influence of river water on zebrafish Danio rerio and water flea Daphnia magna. We observed lethal effects in both species, with Daphnia magna more sensitive to toxicity than Danio rerio. For both species, the toxic effects of river water decreased with increasing distance downstream from the inflow of hot-spring water. Our results show that the heavy metals discharged from Tamagawa hot spring have a negative effect on aquatic organisms.

scholarly journals Monitoring the Biological Effects of Chemicals in River Water using Daphnia magna.

1997 ◽  
Vol 63 (4) ◽  
pp. 627-633 ◽  
Author(s):  
Mikio Kikuchi ◽  
Meiko Wakabayashi
Keyword(s):  
River Water ◽  
Daphnia Magna ◽  
Biological Effects

scholarly journals A 10 Years Study of the Responses of Daphnia magna to River Water in Urbanized Area

2008 ◽  
Vol 18 (3) ◽  
pp. 361-368 ◽  
Author(s):  
Mikio KIKUCHI ◽  
Yoko TOKUNAGA ◽  
Mariko KIKUCHI ◽  
Asuka SATO ◽  
Yukari UMEDA ◽  
...  
Keyword(s):  
River Water ◽  
Daphnia Magna ◽  
Urbanized Area

scholarly journals Polyphenols Extracts From Didymosphenia Geminata (Lyngbye) Schmidt Altered the Motility and Viability of Daphnia Magna

2021 ◽  
Author(s):  
Pamela Olivares-Ferretti ◽  
Viviana Chavez ◽  
Klaudia Hernandez ◽  
Matías Peredo-Parada ◽  
Jorge Parodi
Keyword(s):  
River Water ◽  
Daphnia Magna ◽  
Aquatic Species ◽  
Didymosphenia Geminata ◽  
Controlled Conditions

Abstract The invasive diatom Didymosphenia geminata (Lyngbye) Schmidt, D. geminata has invaded the austral zone of Chile, causing significant ecological, scientific and societal concerns. We aimed to evaluate the viability and motility Daphnia magna (D. magna), as a biosensor for effects of D. geminata. Toxicity assays were performed in dilutions of river water alone (V/V dilution) and in river water contaminated with D. geminata (V/V dilution) or polyphenols extracted from D. geminata under controlled conditions and different time (acute 30 min and 7 hrs). Our results indicated that D. magna was sensitive to increasing concentrations of D. geminata extracts. We observed a 50% (IC50) viability reduction after 24 h of exposure to a 0.023 V/V dilution and the same value when using polyphenols from D. geminata; additionally, this treatment further reduced the motility capacity by 50% after 72 h. The D. magna organisms were acutely responsive, showing a 50% reduction in frequency at 15 min. We conclude that D. magna is sensitive to polyphenols produced by D. geminata in rivers, suggesting potential chronic toxic consequences on several aquatic species following exposure to these diatom substances.

Membrane-bound vesicles associated with the microvilli in the midgut of the freshwater microcrustacean, Daphnia magna

1983 ◽  
Vol 41 ◽  
pp. 480-481
Author(s):  
Patricia L. Jansma
Keyword(s):  
Daphnia Magna ◽  
Intestinal Epithelial Cells ◽  
Uranyl Acetate ◽  
Intestinal Epithelial ◽  
Chlamydomonas Reinhardii ◽  
Thin Sections ◽  
Saturated Water ◽  
Cacodylate Buffer ◽  
Membrane Bound ◽  
Ethanol Series

The presence of the membrane bound vesicles or blebs on the intestinal epithelial cells has been demonstrated in a variety of vertebrates such as chicks, piglets, hamsters, and humans. The only invertebrates shown to have these microvillar blebs are two species of f1ies. While investigating the digestive processes of the freshwater microcrustacean, Daphnia magna, the presence of these microvillar blebs was noticed.Daphnia magna fed in a suspension of axenically grown green alga, Chlamydomonas reinhardii for one hour were narcotized with CO2 saturated water. The intestinal tracts were excised in 2% glutaraldehyde in 0.2 M cacodyl ate buffer and then placed in fresh 2% glutaraldehyde for one hour. After rinsing in 0.1 M cacodylate buffer, the sample was postfixed in 2% OsO4, dehydrated with a graded ethanol series, infiltrated and embedded with Epon-Araldite. Thin sections were stained with uranyl acetate and Reynolds lead citrate before viewing with the Philips EM 200.

Computer Reconstruction of the Cellular Architecture of the Daphnia Magna Optic Ganglion

1975 ◽  
Vol 33 ◽  
pp. 284-285
Author(s):  
E. R. Macagno ◽  
C. Levinthal
Keyword(s):  
Daphnia Magna ◽  
Genetic Background ◽  
Compound Eye ◽  
Synaptic Connectivity ◽  
Serial Sections ◽  
Cross Sectional ◽  
Small Crustacean ◽  
Optic Ganglion ◽  
Structural Invariance ◽  
High Degree

The optic ganglion of Daphnia Magna, a small crustacean that reproduces parthenogenetically contains about three hundred neurons: 110 neurons in the Lamina or anterior region and about 190 neurons in the Medulla or posterior region. The ganglion lies in the midplane of the organism and shows a high degree of left-right symmetry in its structures. The Lamina neurons form the first projection of the visual output from 176 retinula cells in the compound eye. In order to answer questions about structural invariance under constant genetic background, we have begun to reconstruct in detail the morphology and synaptic connectivity of various neurons in this ganglion from electron micrographs of serial sections (1). The ganglion is sectioned in a dorso-ventra1 direction so as to minimize the cross-sectional area photographed in each section. This area is about 60 μm x 120 μm, and hence most of the ganglion fit in a single 70 mm micrograph at the lowest magnification (685x) available on our Zeiss EM9-S.

Silicon Substitution for Calcium in the Shell of the Fingernail Clam, Musculium Transversum Studied By X-Ray Analysis

1980 ◽  
Vol 38 ◽  
pp. 560-561
Author(s):  
Judith A. Murphy ◽  
Anthony Paparo ◽  
Richard Sparks
Keyword(s):  
Carbonic Anhydrase ◽  
River Water ◽  
Food Chains ◽  
Well Water ◽  
Shell Formation ◽  
X Ray ◽  
Molluscan Shell ◽  
Fingernail Clams

Fingernail clams (Muscu1ium transversum) are dominant bottom-dwelling animals in some waters of the midwest U.S. These organisms are key links in food chains leading from nutrients in water and mud to fish and ducks which are utilized by man. In the mid-1950’s, fingernail clams disappeared from a 100-mile section of the Illinois R., a tributary of the Mississippi R. Some factor(s) in the river and/or sediment currently prevent clams from recolonizing areas where they were formerly abundant. Recently, clams developed shell deformities and died without reproducing. The greatest mortality and highest incidence of shell deformities appeared in test chambers containing the highest proportion of river water to well water. The molluscan shell consists of CaCO3, and the tissue concerned in its secretion is the mantle. The source of the carbonate is probably from metabolic CO2 and the maintenance of ionized Ca concentration in the mantle is controlled by carbonic anhydrase. The Ca is stored in extracellular concentric spherical granules(0.6-5.5μm) which represent a large amount of inertCa in the mantle. The purpose of this investigation was to examine the role of raw river water and well water on shell formation in the fingernail clam.

Mise en évidence des effets sublétaux sur des populations de daphnies (Daphnia magna)

1981 ◽  
Vol 12 (1) ◽  
pp. 63-79
Author(s):  
R. Cabridenc ◽  
Bui Thi ◽  
H. Lepailleur
Keyword(s):  
Daphnia Magna
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