Rheotaxis of Elvers of the American Eel (Anguilla rostrata) in the Laboratory to Water from Different Streams in Nova Scotia

1968 ◽  
Vol 25 (8) ◽  
pp. 1591-1602 ◽  
Author(s):  
S. G. Miles
Keyword(s):  
Organic Matter ◽  
Nova Scotia ◽  
Fresh Water ◽  
Stream Water ◽  
Salt Water ◽  
The Other ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Heat Stable ◽  
Experimental Apparatus

In an experimental apparatus, elvers of the American eel (Anguilla rostrata) showed a stronger positive rheotaxis to fresh water than to salt water. The attractiveness of the fresh water was due to dissolved and particulate organic matter; these components were bio-degradable, heat stable, and nonvolatile. Four streams near Halifax, Nova Scotia, were tested, and were found to differ greatly in their attraction of elvers. Elvers were collected from each of three of these streams, and were not found to be attracted to their own stream water; elvers from one stream gave a greater rheotactic response than elvers from the other streams. The presence of adult eels in the water rendered it more attractive, whereas the presence of elvers made it less so.

scholarly journals American eel,Anguilla rostrata, growth in fresh and salt water: implications for conservation and aquaculture

2009 ◽  
Vol 16 (4) ◽  
pp. 306-314 ◽  
Author(s):  
H. M. LAMSON ◽  
D. K. CAIRNS ◽  
J.-C. SHIAO ◽  
Y. IIZUKA ◽  
W.-N. TZENG
Keyword(s):  
Salt Water ◽  
Anguilla Rostrata ◽  
American Eel

The American Eel in Certain Fresh Waters of the Maritime Provinces of Canada

1955 ◽  
Vol 12 (2) ◽  
pp. 238-269 ◽  
Author(s):  
M. W. Smith ◽  
J. W. Saunders
Keyword(s):  
Organic Matter ◽  
Salt Water ◽  
Annual Rings ◽  
Maritime Provinces ◽  
Game Species ◽  
American Eel ◽  
Fresh Waters ◽  
Heavy Rains

Estimated standing crops of eels in eight Maritime lakes treated with fish poisons varied from 0 to 70.8 pounds per acre. Smaller standing crops were associated with greater distances of lakes from the sea, and with obstructions to ascending elvers. Few eels were found in small spring-fed streams. The eel is prominent in Maritime lakes, but frequently is not more successful than other fish considered inimical to game species. Seaward migrations of eels may represent major losses of organic matter to lakes.Scales appear on young eels at lengths from 16 to 20 centimetres, probably in their third or fourth year of age. Nine year-classes were found among eels with scales in each of three limnetic populations. Eels with three and four annual rings on the scales were dominant in the runs from lakes.Runs of eels from lakes occurred in April and May, and again, in larger numbers, from late August through November. These movements were at night, and usually coincident with rising water during and immediately following heavy rains. Silvering, an index of maturity, was manifest among only a portion of the largest of these eels. Fall runs of large eels from salt water into streams have been noted. Upstream movements of elvers are most prominent in May and June, although they attempted to bypass a barrier in the outlet of one lake throughout the summer.

Studies of Fish Spoilage: III. The Trimethylamine Oxide Content of the Muscles of Nova Scotia Fish

1939 ◽  
Vol 4b (4) ◽  
pp. 229-232 ◽  
Author(s):  
S. A. Beatty
Keyword(s):  
Nova Scotia ◽  
Fresh Water ◽  
Salt Water ◽  
Anadromous Fish ◽  
Oxide Content ◽  
Trimethylamine Oxide ◽  
Fish Spoilage ◽  
Water Fish

Trimethylamine oxide was found in the muscle press juice of all salt water fish examined and in the anadromous fish Pomolobus pseudoharengus taken from the sea. Traces were found in Anguilla taken from salt water, but none in Anguilla from fresh water.

scholarly journals HYDROGEOCHEMICAL CONDITION OF THE PIKROLIMNI LAKE (KILKIS GREECE)

2004 ◽  
Vol 36 (1) ◽  
pp. 192
Author(s):  
E. Dotsika ◽  
Y. Maniatis ◽  
E. Tzavidopoulos ◽  
D. Poutoukis ◽  
K. Albanakis
Keyword(s):  
Fresh Water ◽  
Major Ions ◽  
Salt Water ◽  
Field Measurements ◽  
The Other ◽  
Chemical Analyses ◽  
Temperature Conductivity ◽  
Analytical Scheme ◽  
Hydrochemical Data ◽  
High Degree

In order to understand the hydrogeochemical conditions of the basin of Pikrolimni we collected water samples from the borehole in the thermal spa of Pikrolimni and samples of brine and sediments from the lake. We also sampled fresh water of the region. The depth of the borehole in the thermal spa is approximately 250 meters. This water is naturally sparkling, with a metallic aftertaste and a slight organic smell. The samples were taken twice during the year: in summer (8/2002) and in winter (2003). The analytical scheme includes field measurements of temperature, conductivity and pH. Major ions (Na+, K+, Ca2+, Mg2\ CI", Br, S04 2", C03 2", HC03", N03"), F and Br were determined, in laboratory, according to standard analytical methods. Samples were also subjected to isotopie analysis of δ Ο and δ2Η. The results from the chemical analyses of the samples, show that the waters taken from the borehole, are of the type Mg- (Na-Ca)-HCC>3 and the salts of the lake are of the type Na-CI- (CO3-S04). The salts of the lake result from mixing and condensation of the waters which are accumulated in the basin of the lake, and come not only from sources that feed the lake, e.g. waters from borehole, but also from rain water. The waters of these sources are mainly of meteoritic origin and circulate deeply, mixing probably with salt water of deeper and probably of warmer horizons. The latter comes in agreement with the hydrothermal field, which exists in the area. From hydrochemical data, the brines of summer clearly correspond to waters, which have been submitted under high degree of evaporation: they are residual mother solutions before the step of the precipitation of halite. During winter, dilution of brines and dissolution of depositing minerals by fresh water are observed. On the other hand, evaporating conditions are created in the lake during summer.

Total Mercury and Methylmercury Content of the American Eel (Anguilla rostrata)

1973 ◽  
Vol 30 (3) ◽  
pp. 454-456 ◽  
Author(s):  
H. C. Freeman ◽  
D. A. Horne
Keyword(s):  
Nova Scotia ◽  
Total Mercury ◽  
Mercury Content ◽  
Human Consumption ◽  
Anguilla Rostrata ◽  
American Eel ◽  
The Mean ◽  
American Eels

In American eels (Anguilla rostrata) caught in Nova Scotia, the total mercury content was found to be 0.72 ± 0.05 ppm and the methylmercury content was 0.40 ± 0.06 ppm (mean ± SE for 23 fish). Since the mean total mercury content was less than 1 ppm and the toxic methylmercury content was 50% of this, or less than the 0.5 ppm guideline, such eels may be acceptable for human consumption.

scholarly journals Changes in the amount of soluble carbohydrates and polyphenols contents during decomposition of Montrichardia arborescens (L.) Schott

2003 ◽  
Vol 33 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Marcela Bianchessi da Cunha-Santino ◽  
Lucilia Dias Pacobahyba ◽  
Irineu Bianchini Jr
Keyword(s):  
Weight Loss ◽  
Organic Matter ◽  
Anaerobic Degradation ◽  
Stream Water ◽  
Aerobic Condition ◽  
The Other ◽  
Soluble Carbohydrates ◽  
Anaerobic Conditions ◽  
Anaerobic Process ◽  
Aerobic And Anaerobic

This study describes the aerobic and anaerobic decay of soluble carbohydrates (CH) and polyphenols (PH) during decomposition of Montrichardia arborescens. Plant and water samples were collected in the Cantá stream (2º 49' 11" N and 60º 40' 24" W), Roraima, Brazil. Decomposition chambers with plant fragments and stream water were incubated. Particulate organic matter was separated from dissolved organic matter and concentrations of CH and PH were determined. The results were fitted to 1st order kinetics models. CH and PH comprised a labile fraction (LCH and LPH) and a refractory fraction (RCH and RPH). The global coefficient associated with LCH weight loss was 1.4 times higher under aerobic conditions (3.4 day-1) higher than for anaerobic conditions. On the other hand, the RCH decay rate in the anaerobic process (0.0074 day-1) was 1.39 times higher. LCH was estimated to be 92% while RCH amounted to 8%. The LPH anaerobic decay was 5.2 times the value for the aerobic decay (0.67 day-1). For both conditions, RPH decay coefficients were similar (» 0.011 day-1). In the aerobic experiments LPH and RPH corresponded to 92.5% and 7.5%, respectively. For the anaerobic process these contents were 85.5% and 14.5%, respectively. From these results, we concluded that in the Cantá stream, the anaerobic degradation of phenols is more efficient than the aerobic counterpart. The aerobic condition provides a faster decay of carbohydrates of this plant.

On friction and surface cracking during sliding of ice on ice

2003 ◽  
Vol 49 (166) ◽  
pp. 391-396 ◽  
Author(s):  
Maurine Montagnat ◽  
Erland M. Schulson
Keyword(s):  
Fresh Water ◽  
Kinetic Coefficient ◽  
Salt Water ◽  
The Other ◽  
Surface Cracks ◽  
Experimental Conditions ◽  
Water Ice ◽  
Surface Cracking ◽  
Double Shear ◽  
Deformation Features

AbstractAs a complement to earlier measurements on the friction of both granular fresh-water ice and S2 columnar salt-water ice, new experiments were performed on the friction of S2 columnar fresh-water ice sliding against itself at low velocities (5 × 10−7 to 5 × 10−1 m s−1) and at −10°C, using the same double-shear device as was used earlier. The results showed that under a given set of experimental conditions the kinetic coefficient of friction of S2 fresh-water ice compares favorably with that of the other two variants.The experiments also revealed friction-induced surface cracks and recrystallized grains.These deformation features are explained, respectively, in terms of fracture mechanics and an earlier model of dynamic recrystallization in ice.

Survival of certain naturally acquired freshwater parasites of juvenile sockeye salmon, Oncorhynchus nerka (Walbaum), in hosts held in fresh and sea water, and implications for their use as population tags

1989 ◽  
Vol 67 (7) ◽  
pp. 1757-1766 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis ◽  
G. D. Workman
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Water Samples ◽  
Sockeye Salmon ◽  
Sea Water ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Maximum Life Span ◽  
Natural Tags

Sockeye salmon (Oncorhynchus nerka) smolts were captured from the outlet streams of Cultus Lake, British Columbia, in 1985 and 1986, and from Fraser Lake, British Columbia, in 1986. Samples collected in 1985 were reared in salt water. Samples collected from each lake in 1986 were divided equally into two groups: one group was reared in fresh water, the other was maintained in salt water. Initially biweekly, and later monthly, subsamples from each group were examined for seven parasite taxa: Myxidium salvelini, Diplostomulum sp. metacercaria, Phyllodistomum umblae, Eubothrium sp. (immature), Proteocephalus sp. (immature), Neoechinorhynchus salmonis, and Salmincola californiensis. The maximum life-span was greater than the duration of the experiments (32–40 weeks) for all species in hosts reared in fresh water (except for S. californiensis, which was removed from all freshwater hosts). Survival of M. salvelini, P. umblae, and S. californiensis was reduced in hosts reared in sea water. No differences in survival of each of Diplostomulum sp. metacercaria, Eubothrium sp., Proteocephalus sp., and N. salmonis were observed between hosts held in fresh water or salt water. Implications for the use of these parasites as natural tags are discussed.

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