Population Dynamics of Ornithodiplostomum ptychocheilus Metacercariae in Fathead Minnows (Pimephales promelas) from Four Northern-Alberta Lakes

2001 ◽  
Vol 87 (4) ◽  
pp. 744 ◽  
Author(s):  
Gregory J. Sandland ◽  
Cameron P. Goater ◽  
Andy J. Danylchuk
1998 ◽  
Vol 55 (1) ◽  
pp. 15-27 ◽  
Author(s):  
W G Duffy

I assessed the population dynamics of fathead minnows (Pimephales promelas) in prairie wetlands and developed a bioenergetics model to estimate their production and prey consumption. I sampled populations in four wetlands weekly from late May through June and biweekly during July and August using a Kushlan 1-m2 throw trap. I imposed commercial harvest on two populations; the other two populations served as controls. Weekly population density estimates ranged from 52 000 to 356 000 ·ha-1 during early June and from 5400 to 19 700 ·ha-1 in late August. Simulated commercial harvest did not influence population density, mortality rates, or size of fathead minnows. Standing stock biomass differed among wetlands sampled, ranging from 144 to 482 kg ·ha-1 in early June and from 1 to 33 kg ·ha-1 during late August. However, differences were attributed to differential predation pressure rather than harvest pressure. Net production during the period ranged from 71.5 to 202.7 kg ·ha-1. Daily net production was greatest in early June (2.6-13.5 kg ·ha-1 ·day-1) and then declined during July and August (0.1-1.2 kg ·ha-1 ·day-1). Total mass of prey consumed by fathead minnows ranged from 332.7-1104.8 kg ·ha-1 among wetlands.


Author(s):  
Richard L. Leino ◽  
Jon G. Anderson ◽  
J. Howard McCormick

Groups of 12 fathead minnows were exposed for 129 days to Lake Superior water acidified (pH 5.0, 5.5, 6.0 or 6.5) with reagent grade H2SO4 by means of a multichannel toxicant system for flow-through bioassays. Untreated water (pH 7.5) had the following properties: hardness 45.3 ± 0.3 (95% confidence interval) mg/1 as CaCO3; alkalinity 42.6 ± 0.2 mg/1; Cl- 0.03 meq/1; Na+ 0.05 meq/1; K+ 0.01 meq/1; Ca2+ 0.68 meq/1; Mg2+ 0.26 meq/1; dissolved O2 5.8 ± 0.3 mg/1; free CO2 3.2 ± 0.4 mg/1; T= 24.3 ± 0.1°C. The 1st, 2nd and 3rd gills were subsequently processed for LM (methacrylate), TEM and SEM respectively.Three changes involving chloride cells were correlated with increasing acidity: 1) the appearance of apical pits (figs. 2,5 as compared to figs. 1, 3,4) in chloride cells (about 22% of the chloride cells had pits at pH 5.0); 2) increases in their numbers and 3) increases in the % of these cells in the epithelium of the secondary lamellae.


1983 ◽  
Vol 17 (1) ◽  
pp. 47-63 ◽  
Author(s):  
James A. Zischke ◽  
John W. Arthur ◽  
Kathleen J. Nordlie ◽  
Roger O. Hermanutz ◽  
Douglas A. Standen ◽  
...  

2004 ◽  
Vol 23 (12) ◽  
pp. 2900 ◽  
Author(s):  
Katherine L. Sciera ◽  
J. Jeffery Isely ◽  
Joseph R. Tomasso ◽  
Stephen J. Klaine

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