scholarly journals Effects of meal and body sizes on gastric evacuation rate in brooktrout Salvelinus fontinalis (Mitchill, 1814) fed commercial pellets in group feeding

2017 ◽  
Vol 64 (3) ◽  
Author(s):  
N. S. Bascinar ◽  
N. Bascinar ◽  
U. Khan ◽  
K. Seyhan
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Gastric Evacuation ◽  
Root Model ◽  
Feeding Regimes ◽  
Body Sizes ◽  
Group Feeding ◽  
Gastric Evacuation Rate ◽  
Square Root Model

The effects of meal and body sizes on gastric evacuation (GE) of brook trout Salvelinus fontinalis (Mitchill, 1814) were determined following group feeding instead of feeding individually maintained fish. The GE experiments included small (ranging from 64.75 to 69.72 g) and large fish (ranging from 161.59 to 170.95 g). Fish in each size group was fed with three different meal sizes under similar conditions. The stomach contents were then recovered at predetermined postprandial times by serial slaughtering. The square root model adequately described the course of GE in S. fontinalis independent of meal size. The estimates of mass and length exponent obtained from S. fontinalis fed individually are in line with the present estimates. The result of this study would facilitate the planning and management of feeding regimes for S. fontinalis to minimise food waste and optimise growth.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

Temporal and spatial variation in the energy intake of a brook trout (Salvelinus fontinalis) population in an Appalachian watershed

2006 ◽  
Vol 63 (12) ◽  
pp. 2675-2686 ◽  
Author(s):  
Ryan M Utz ◽  
Kyle J Hartman
Keyword(s):  
Energy Intake ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Spatial And Temporal Variation ◽  
Feeding Rates ◽  
Temporal And Spatial Variation ◽  
The Mean ◽  
Temporal And Spatial ◽  
Very High

Stream-dwelling salmonids in eastern North America are often restricted to headwater watersheds, where productivity is low and thus feeding conditions are poor. We sought to quantify how energy intake varies with spatial and temporal variation by monitoring feeding rates in multiple sites over the course of two years. Daily rations were calculated for 939 fish by examining stomach contents. Maintenance rations were compared with daily rations using a bioenergetics model. Consumption peaked in spring, dropped substantially in summer, and remained low until the following spring. A minority of fish fed at very high levels during all seasons, elevating the mean consumption of the population. Fish occupying large sites with low trout densities consistently consumed more energy than fish in smaller streams with high trout densities. A direct relationship between trout density and mean consumption was observed during summer, when feeding conditions were poorest. Our findings suggest that within a headwater watershed, larger reaches of streams where fewer trout are found act as important feeding areas and thus may be important habitat for brook trout (Salvelinus fontinalis).

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Regression Analysis ◽  
Gastric Lavage ◽  
Stomach Contents ◽  
Exponential Model ◽  
Spiny Dogfish ◽  
Square Root ◽  
Gastric Evacuation ◽  
San Juan Islands ◽  
Gastric Evacuation Rate ◽  
Over Time

Abstract.—Gastric evacuation rate was estimated for immature spiny dogfish <em>Squalus acanthias </em>from the San Juan Islands, Washington. Dogfish were fed known quantities of herring and removed at intervals after feeding to recover the remaining portion of the meal. Stomach contents were recovered using the non-lethal technique, gastric lavage. Regression analysis was used to evaluate the adequacy of linear, square root, and exponential models in describing the decrease in stomach contents over time. An exponential model proved best at describing the pattern of evacuation. Gastric evacuation in immature dogfish was comparable to that of other elasmobranchs of similar size at similar temperatures. Re-using test subjects did not significantly impact gastric evacuation estimates.

scholarly journals Ignoring the vertical dimension: biased view on feeding dynamics of vertically migrating sprat (Sprattus sprattus)

2018 ◽  
Vol 75 (7) ◽  
pp. 2450-2462
Author(s):  
Rini Kulke ◽  
Viola Bödewadt ◽  
Kristin Hänselmann ◽  
Jens-Peter Herrmann ◽  
Axel Temming
Keyword(s):  
Sampling Design ◽  
Stomach Contents ◽  
Prey Selectivity ◽  
Gastric Evacuation ◽  
New Approach ◽  
Predator Prey ◽  
Feeding Periodicity ◽  
Different Depths ◽  
Common Behaviour ◽  
Gastric Evacuation Rate

Abstract Diel vertical migration (DVM) is a common behaviour and often relates with the diurnal feeding periodicity. Nonetheless, sprat feeding behaviour and daily ration (DR) estimation are usually based on daytime stomach contents from deeper layers. Our study provides a new approach for DR estimation, taking into consideration the DVM associated feeding periodicity. We analysed sprat DVM by hydroacoustics and collected stomach contents in the Central Baltic Sea at different depths. The main outcome is that feeding in the deep during the day represents only 16–39% of the DR. DRs were 1.4-times higher using our approach compared to the established approach. The underestimation by the established approach was mainly caused by ignoring the effect of higher temperatures from the upper layers on the gastric evacuation rate. Our results have major implications not only for DR estimates but also on the interpretation of prey selectivity. The study emphasizes the importance of adapting the sampling design to the vertical feeding dynamics to avoid a biased picture of predator prey interactions.

scholarly journals Gastric Evacuation in Brook Trout (Salvelinus fontinalis) Fry: Effect of Body Size

2020 ◽  
Vol 52 (3) ◽  
Author(s):  
Kadir Seyhan ◽  
Nimet Selda Başçinar ◽  
Nadir Başçinar ◽  
Umar Khan
Keyword(s):  
Body Size ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Gastric Evacuation
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