Rate of Gastric Evacuation for Winter Flounder, Pseudopleuronectes americanus

1982 ◽  
Vol 39 (2) ◽  
pp. 356-360 ◽  
Author(s):  
Judith D. Huebner ◽  
Richard W. Langton

The rate of gastric evacuation of winter flounder, Pseudopleuronectes americanus, calculated from the rate of hunger return (determined as the amount eaten voluntarily at some time following a satiation meal) at ~ 6 °C was exponential and equaled 0.079 h−1. Feeding voluntarily on small pieces of squid, the fish ate 1.8–2.4% of their body weight per day, the actual weight of food consumed varying directly with fish weight so that ln wt food (g) = −2.988 + 0.780 ln wet wt fish (g). Stomach volume also varied with fish weight: stomach vol (cm3) = 0.923 + 0.039 wet wt fish (g). Preliminary estimates of daily ration using several independent models agree closely with laboratory measurements of daily consumption.Key words: winter flounder, gastric, evacuation

1987 ◽  
Vol 65 (3) ◽  
pp. 499-503 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
Kenneth G. Waiwood

Feeding chronologies of three species of cohabiting benthic fish, winter flounder (Pseudopleuronectes americanus), ocean pout (Macrozoarces americanus), and American plaice (Hippoglossoides platessoides), are described. The volume of food eaten by each species at each of four collection times over 24 h was analysed using analysis of covariance (ANCOVA), with fish length as the covariate. Daily ration was estimated using a gastric evacuation model, incorporating mean stomach volumes at four subdaily intervals and independent evacuation rates for slower (bivalves) and faster digested prey (amphipods and polychaetes). Winter flounder, American plaice, and ocean pout were daylight feeders with American plaice feeding more heavily later in the day. Winter flounder had the highest consumption rate (1.77% body weight/day) followed by ocean pout (1.68%) and American plaice (1.28%). Estimates of daily and subdaily food consumption were compared with corresponding estimates based on prey-specific state of digestion indices. This study indicates that estimating total and individual prey consumption at subdaily intervals provides a useful tool in determining feeding chronology and draws attention to potential biases encountered when more traditional analyses are used.


1971 ◽  
Vol 28 (12) ◽  
pp. 1907-1911 ◽  
Author(s):  
R. A. Voyer ◽  
G. E. Morrison

In one series of experiments, average rates of oxygen consumed by winter flounder at 10 C were 35 and 55 mg O2/kg of body weight per hour at 3.5 and 8.6 mg dissolved oxygen (DO)/liter, respectively. At 20 C the average rates of oxygen uptake were 70 at 3.2 mg DO/liter and 97 at 6.3 mg DO/liter. Oxygen consumption rates were significantly greater (P <.05) at 20 C than at 10 C. In two of the three experiments, rates of oxygen uptake were significantly lower (P <.05) among groups of winter flounder maintained at the reduced dissolved oxygen concentrations for 15–23 hr. No dissolved oxygen–temperature interactions were apparent.Results of a second series of experiments indicated respiration rates of winter flounder increased linearly with weight along regression lines having slopes of 0.792 (20 C — 6.9 mg DO/liter), 0.785 (20 C — 4.3 mg DO/liter), 0.720 (10 C — 8.7 mg DO/liter), and 0.746 (10 C — 4.3 mg DO/liter).


1972 ◽  
Vol 29 (1) ◽  
pp. 67-77 ◽  
Author(s):  
B. S. Muir ◽  
A. J. Niimi

Active and standard metabolism of Kuhlia sandvicensis increase with fish weight to a power of about 0.8 and active is nine times standard. No significant difference was found between experiments in fresh water and 30‰ sea water at 23 C. At low swimming speeds the fish may be unable to physically take up as much oxygen as at higher speeds. Swimming activity may be essential to circulatory adequacy.Elevated oxygen consumption lasted for 42 hr following a ration of 2.3% of body weight and for 60 hr after one of 4.5%. It amounted to about 76 mg O2/g ration, equivalent to about 16% of the energy of the ration, in both cases. For a nonswimming fish the highest oxygen consumption observed following the maximum daily ration is no more than half of the difference between active and standard rates.


1983 ◽  
Vol 40 (7) ◽  
pp. 854-865 ◽  
Author(s):  
Gary L. Foureman ◽  
Nathaniel B. White Jr. ◽  
John R. Bend

Livers from winter flounder (Pseudopleuronectes americanus) captured near Mount Desert Island, Maine, showed marked variation in hepatic benzo[a]pyrene hydroxylase (AHH; from 0.04 to 8.8 FU∙min−1∙mg protein−1) and 7-ethoxyresorufin deethylase activities (7-ERD; from < 2 to 1165 pmol∙min−1∙mg protein−1), and a dichotomy in the effect of 7,8-benzoflavone (ANF) added in vitro on AHH activity. Based on this ANF effect, the flounder could be divided into two groups. One group had high 7-ERD activity and high AHH activity which was inhibited by ANF; the other group had low 7-ERD activity and low AHH activity which was enhanced by ANF. Sex, weight, length, liver weight, gonad weight/body weight ratio, and liver/body weight ratio explained only a small part of the variability in hepatic AHH activities. Electrophoretograms of hepatic microsomes from flounder treated with 1,2,3,4-dibenzanthracene (DBA) or 5,6-benzoflavone (βNF) showed a novel or enriched polypeptide species present near 57 000 daltons, in the molecular weight (MW) range of known cytochrome P-450 isozymes. A polypeptide of similar MW was only faintly discernable in liver microsomes from untreated flounder whose hepatic AHH activity was much lower than that of the treated flounder, whereas a band of this MW was prominent in hepatic microsomes from untreated flounder with high hepatic AHH activity. These results suggest that many of the winter flounder captured near Mount Desert Island, Maine have induced hepatic monooxygenase activity due to exposure to PAH or PAH-like inducers present in their natural habitat.


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.


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