A Sigmoid Model to Predict Gastric Evacuation Rates of Smallmouth Bass (Micropterus dolomieui) Fed Juvenile Salmon

1991 ◽  
Vol 48 (5) ◽  
pp. 933-937 ◽  
Author(s):  
Jean Beyer Rogers ◽  
Craig C. Burley

Laboratory experiments were conducted to examine the effects of water temperature, predator size, prey size, and prey number on gastric evacuation of smallmouth bass (Micropterus dolomieui) fed juvenile salmon. The smallmouth bass were allowed to feed voluntarily after 24–48 h of starvation and stomachs were pumped at intervals of 1–4 h until 90% of the stomach contents were evacuated (E90). Evacuation approximated an S-shaped curve over time, and a sigmoid model was developed to predict evacuation at varying water temperatures, total meal weights, predator sizes, and prey number. The rate of evacuation increased with increasing water temperature, meal weight, or predator size. The E90 increased with larger meal weights but decreased with increasing temperature or predator size. E90 ranged between 4 and 95 h, depending upon conditions. E90 was slower than those estimated previously for another predator of salmon, the stomachless northern squawfish (Ptychocheilus oregonensis).


1981 ◽  
Vol 59 (12) ◽  
pp. 2322-2330 ◽  
Author(s):  
Hugh R. MacCrimmon ◽  
William H. Robbins

Behaviour of wild juvenile smallmouth bass, Micropterus dolomieui, in the laboratory was significantly influenced by water temperature, current, and illumination. Activity increased with increasing water temperature and (or) water current. When exposed to black and white substrate, selection of black was inversely dependent on temperature and current, and highly correlated with fish activity (r = 0.995, P < 0.001, inverse cubic relation). Substrate pattern influenced fish activity, aggregation, and social interaction. Activity levels increased with increasing incident illumination whereas selection of black substrate declined, particularly at higher water temperatures. Older juveniles became less active with age and preferred black substrate when available, thereby indicating a developing behavioural pattern which favours survival and energy conservation under natural nursery conditions by the discrete use of available cover.



1977 ◽  
Vol 34 (1) ◽  
pp. 142-147 ◽  
Author(s):  
William H. Robbins ◽  
Hugh R. MacCrimmon

Between 1968 and 1971, upriver movement of bass from Lake Simcoe was highly correlated with water temperature and discharge (r = 0.704, P <.001). Vital statistics and growth were similar to lacustrine and riverine stocks at similar latitude. Total annual mortality averaged 0.56 with 65% attributable to angler exploitation, principally in the river. Some 34% (after mortality) river spawners returned upriver in subsequent years. Repeat spawners (65% female) comprised an average 19% of the spawning runs. Most adults moved downriver in late June and July when water temperatures approached 25 °C. Adults remaining in the spawning area experienced water temperatures to 29 °C before emigrating during freshets in July and August. Lake migrants intermingled on shoal areas with lacustrine and possibly other potamodromous stocks each summer.



Author(s):  
M. A. Collins ◽  
G. J. Pierce

The size of fish and squid prey of Loligo forbesi was investigated using otoliths, beaks and statoliths collected from stomach contents analysis of samples obtained from Scottish and Irish waters between 1990 and 1993. Loligo forbesi was found to consume a large range of prey sizes, but prey size was always less than the predator size. Season was shown to significantly influence the predator size-prey size relationship for sprat and sandeel prey, but this itself could be influenced by seasonal changes in the size of prey. Fish prey size increased with increased predator size up to a mantle length (ML) of 200 mm. Loligo forbesi of mantle length >200 mm consumed a range of prey sizes, with no clear increase in the size of prey. For most prey taxa the relationship between prey size and squid size was similar, the exceptions being dragonets and silvery pout. Cannibalism by L. forbesi was mostly limited to larger L. forbesi (>150 mm ML) feeding on smaller (20–50 mm ML) conspecifics.



2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicholas L. Payne ◽  
Simon A. Morley ◽  
Lewis G. Halsey ◽  
James A. Smith ◽  
Rick Stuart-Smith ◽  
...  

AbstractExtrapolating patterns from individuals to populations informs climate vulnerability models, yet biological responses to warming are uncertain at both levels. Here we contrast data on the heating tolerances of fishes from laboratory experiments with abundance patterns of wild populations. We find that heating tolerances in terms of individual physiologies in the lab and abundance in the wild decline with increasing temperature at the same rate. However, at a given acclimation temperature or optimum temperature, tropical individuals and populations have broader heating tolerances than temperate ones. These congruent relationships implicate a tight coupling between physiological and demographic processes underpinning macroecological patterns, and identify vulnerability in both temperate and tropical species.



1969 ◽  
Vol 26 (7) ◽  
pp. 1801-1812 ◽  
Author(s):  
John T. Windell ◽  
David O. Norris ◽  
James F. Kitchell ◽  
James S. Norris

Quantitative data are presented for three laboratory experiments concerning rate of gastric evacuation of pellets (fed in gelatin capsules) and pellet components. Rainbow trout, Salmo gairdneri, acclimated to a constant water temperature of 15 C were killed 12 hr after consuming an experimental meal. Subtraction of amount of dry matter remaining at autopsy from dry matter consumed yielded amount of food digested or evacuated or both, from the stomach per unit time.Meals of encapsulated pellet were evacuated from the stomach more rapidly (65.8% decrease in 12 hr) than encapsulated corn oil (42.6%), gelatin (50.8%), a combination of corn oil and gelatin (47.3%), saturated fat (28.8%), or methyl cellulose (50.3%).Groups of fish consuming five capsules equal to approximately 0.65 % of their body weight evacuated 35.9, 45.1, 64.2, 95.5, and 100% at intervals after killing from 6 to 36 hr, respectively. Similar groups consuming seven capsules equal to approximately 1.0% of their body weight evacuated 23.7, 57.9, 70.5, and 86.6% at intervals after killing from 4 to 20 hr, respectively.Ten groups of trout consuming amounts of dry matter equal to 0.24, 0.40, 0.74, 1.11, 1.31, 1.19, 1.59, 1.56, 1.91, and 2.26% of their body weight evacuated 90.7, 81.3, 64.2, 57.9, 56.6, 52.5, 53.4, 51.3, 58.7, and 50.0% in 12 hr, respectively. Gastric motility remains relatively constant once food has entered the stomach. However, when larger meals are fed a greater quantity is evacuated per unit time. This could only be accomplished by changes in volume of gastric contents pumped per peristaltic stroke or number of strokes per unit time.



2004 ◽  
Vol 61 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Allan W Stoner ◽  
Erick A Sturm

Laboratory experiments were conducted to test the hypothesis that temperature (2–8 °C) and recent feeding history (1–6 days of food deprivation) influence feeding motivation and attacks on baits by adult sablefish (Anoplo poma fimbria). Activity level after introduction of a bait-related olfactory cue increased with increasing water temperature and food deprivation. Fish at the lowest temperature (2 °C) attacked and consumed fewer squid baits (33–71%) than those at higher temperatures (100% at 8 °C). Baits were frequently inspected or handled multiple times before consumption in low temperatures, and time to attack (seconds to >40 min), time to consume, and time to handle baits (2–20 s) all decreased significantly with increasing temperature, with some temperature × feeding history interactions. The total ration consumed increased (<1–8% of body weight) with increasing water temperature. The observed variability in activity and feeding motivation in sablefish may have a large impact on the effective area of baited gear but is rarely considered in stock assessment models. In particular, population sizes based upon baited gear surveys may be underestimated in conditions where temperature is low, natural prey density is high, or where other environmental variables reduce feeding motivation.



Clay Minerals ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 223-235 ◽  
Author(s):  
Raúl Fernández ◽  
Ana Isabel Ruiz ◽  
Jaime Cuevas

AbstractConcrete and bentonite are being considered as engineered barriers for the deep geological disposal of high-level radioactive waste in argillaceous rocks. Three hydrothermal laboratory experiments of different scalable complexity were performed to improve our knowledge of the formation of calcium aluminate silicate hydrates (C-A-S-H) at the interface between the two materials: concretebentonite transport columns, lime mortar-bentonite transport columns and a portlandite- (bentonite and montmorillonite) batch experiment. Precipitation of C-A-S-H was observed in all experiments. Acicular and fibrous morphologies with certain laminar characteristics were observed which had smaller Ca/Si and larger Al/Si ratios with increasing temperature and lack of accessory minerals. The compositional fields of these C-A-S-H phases formed in the experiments are consistent with Al/(Si+Al) ratios of 0.2– 0.3 described in the literature. The most representative calcium silicate hydrate (C-S-H) phase from the montmorillonite–cement interface is Al-tobermorite. Structural analyses revealed a potential intercalation or association of montmorillonite and C-A-S-H phases at the pore scale.



2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Satu Ojala ◽  
Ulla Lassi ◽  
Paavo Perämäki ◽  
Riitta L. Keiski

Catalytic oxidation is a feasible and affordable technology for solvent emission abatement. However, finding optimal operation conditions is important, since they are strongly dependent on the application area of VOC incineration. This paper presents the results of the laboratory experiments concerning four most central parameters, that is, effects of concentration, gas hourly space velocity (GHSV), temperature, and moisture on the oxidation of n-butyl acetate. Both fresh and industrially aged commercial Pt/Al2O3catalysts were tested to determine optimal process conditions and the significance order and level of selected parameters. The effects of these parameters were evaluated by computer-aided statistical experimental design. According to the results, GHSV was the most dominant parameter in the oxidation of n-butyl acetate. Decreasing GHSV and increasing temperature increased the conversion of n-butyl acetate. The interaction effect of GHSV and temperature was more significant than the effect of concentration. Both of these affected the reaction by increasing the conversion of n-butyl acetate. Moisture had only a minor decreasing effect on the conversion, but it also decreased slightly the formation of by products. Ageing did not change the significance order of the above-mentioned parameters, however, the effects of individual parameters increased slightly as a function of ageing.





Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 131-137 ◽  
Author(s):  
J. G. Rea ◽  
S. W. B. Irwin

Laboratory experiments indicated that the active life-span of the cercariae of Cryptocotyle lingua was temperature-dependent. An increase in water temperature and population age both correlated with a tendency for the organisms to become decaudate. The larvae were strongly photoresponsive to lateral light but with time, horizontal swimming rates (HSRs) from release point to light source progressively declined. When measured over a range of light quantities, HSRs peaked at 30 μM/m2/s. HSRs were also influenced by water temperature. A rapid increase occurred up to 15 °C after which there was a precipitous decline. HSRs to coloured light were negatively correlated with increasing wavelength. When offered a choice between colours, cercariae favoured the shorter wavelengths. The implications of these responses for successful transmission are discussed.



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