Ration, Growth, and Measures of Somatic and Organ Condition in Relation to Meal Frequency in Winter Flounder, Pseudopleuronectes americanus, with Hypotheses Regarding Population Homeostasis

1976 ◽  
Vol 33 (1) ◽  
pp. 63-75 ◽  
Author(s):  
A. V. Tyler ◽  
R. S. Dunn
Keyword(s):  
Conversion Efficiency ◽  
Egg Production ◽  
Liver Weight ◽  
Condition Index ◽  
Weight Percent ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Feeding Frequency ◽  
Passamaquoddy Bay ◽  
The Face

Six ration levels were established among 120 large, adult winter flounder (Pseudopleuronectes americanus) by setting different feeding frequencies, but with unlimited feeding at each meal. All fish were maintained at 7 C. With decrease in feeding frequency, fish ate less food per month but more food per meal — i.e. ration compensation was attempted. At the lowest frequency, two meals per month, fish did not compensate. At any one feeding frequency, fish ate progressively more per meal from the first to the fourth (final) month of the experiment.Maintenance ration was 7.9 gcal/g per day. Weight loss on starvation was equivalent to 2.14–2.35 gcal/g per day. Gross conversion efficiency ranged from 1 to 16%, and was positively correlated with ration. Net conversion efficiency averages 24.3% and was not related to ration.Positive correlations were found between mean calories consumed per day and condition, liver weight, percent fat in the liver, percent of fish with yolk-bearing ovaries, ovary weight, and percent of ovarian follicles with yolk. The decrease in proportion of yolked oocytes with decrease in ration was not due to increased follicular atresia, but to a decrease in number of oocytes starting vitellogenesis.Comparisons with flounders sampled directly from Passamaquoddy Bay, N.B. showed that the negative correlation between condition index and percentage of oocytes not in vitellogenesis was the same for Bay and laboratory fish, the range of response being greater in the laboratory fish. The existence of this relationship was interpreted as evidence that some flounders within the Bay were not getting all the food they could use. In the face of food scarcity, the winter flounder’s adaptive reproductive strategy seems to be to sacrifice egg production and maintain body weight, and so when a good year comes its body will be large and able to carry a larger ovary.

Studies of the Trematode Stephanostomum baccatum (Nicoll, 1907): II. Biology, with Special Reference to the Stages Affecting the Winter Flounder

1954 ◽  
Vol 11 (6) ◽  
pp. 963-987 ◽  
Author(s):  
R. W. Wolfgang
Keyword(s):  
Seasonal Variation ◽  
Open Water ◽  
Common Species ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Intermediate Hosts ◽  
Buccinum Undatum ◽  
Passamaquoddy Bay ◽  
Inshore Waters ◽  
Hemitripterus Americanus

Stephanostomum baccatum, an acanthocolpid trematode, has the following host succession in eastern Canadian waters: Buccinum undatum and Neptunea decemcostatum (Gastropoda), primary intermediate hosts; the six common species of pleuronenctids, second intermediate hosts; Hemitripterus americanus and Hippoglossus hippoglossus, common definitive hosts. Infection of flatfish is by penetration of the integument of the host by an atypical Ophthalmoxiphidiocercous cercaria.The infection of the winter flounder, Pseudopleuronectes americanus, as investigated in Passamaquoddy Bay, N.B., shows the following characteristics:1. The infection in inshore waters is greater near open water than on shoal grounds.2. For any given location deeper water samples show a higher incidence of infection than shoal samples.3. Larger fish have heavier infections than small ones.4. The growth of the flounder is not impeded by heavy cyst infections.5. No marked seasonal variation of infection can be demonstrated. Control is impractical.

Feeding chronology and daily ration calculations for winter flounder (Pseudopleuronectes americanus), American plaice (Hippoglossoides platessoides), and ocean pout (Macrozoarces americanus) in Passamaquoddy Bay, New Brunswick

1987 ◽  
Vol 65 (3) ◽  
pp. 499-503 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
Kenneth G. Waiwood
Keyword(s):  
Consumption Rate ◽  
Winter Flounder ◽  
Analysis Of Covariance ◽  
Fish Length ◽  
Benthic Fish ◽  
Daily Ration ◽  
Pseudopleuronectes Americanus ◽  
Gastric Evacuation ◽  
Passamaquoddy Bay ◽  
Hippoglossoides Platessoides

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.

Digenean (Trematoda) populations in winter flounder (Pseudopleuronectes americanus) from Passamaquoddy Bay, New Brunswick, Canada

1985 ◽  
Vol 63 (7) ◽  
pp. 1699-1705 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
New Brunswick ◽  
Alimentary Tract ◽  
Feeding Activity ◽  
The Body ◽  
Winter Flounder ◽  
Differential Migration ◽  
Pseudopleuronectes Americanus ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Passamaquoddy Bay

Examination of monthly samples of winter flounder (Pseudopleuronectes americanus) from Passamaquoddy Bay revealed seven digenean parasites (Genolinea laticauda, Podocotyle atomon, Stenakron vetustum, Fellodistomum furcigerum, Derogenes varicus, Lecithaster gibbosus, and Steganoderma formosum) in the alimentary tract and two metacercariae (Stephanostomum baccatum and Cryptocotyle lingua) in the body surface tissues and gills. Prevalence of alimentary tract parasites ranged from 0.2 in S. formosum to 39.8 in P. atomon and intensity ranged from 1.5 for D. varicus to 7.0 for S. formosum (one fish). Monthly and seasonal levels of prevalence varied: high in spring and autumn and low in summer and winter for most species. Prevalence and length-frequency distributions of the parasites did not support differential migration by size group or diminishing feeding activity from spring to winter in winter flounder, as proposed in other studies.

scholarly journals Rebuilding in the face of climate change

2018 ◽  
Vol 75 (9) ◽  
pp. 1405-1414 ◽  
Author(s):  
Richard J. Bell ◽  
Anthony Wood ◽  
Jonathan Hare ◽  
David Richardson ◽  
John Manderson ◽  
...  
Keyword(s):  
Winter Temperature ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Climate Variability And Change ◽  
Regional Warming ◽  
Demographic Rates ◽  
Decadal Scale ◽  
The Face ◽  
Stock Recruitment ◽  
Historical Levels

Decadal-scale climate variability and change can cause trends in oceanographic conditions that impact demographic rates. Rebuilding scenarios, therefore, developed assuming constant demographic rates may not be realistic. Winter flounder (Pseudopleuronectes americanus) is an important commercial and recreational species that has declined in the southern portion of its range despite reduced exploitation. Laboratory and mesocosm studies suggest that stock productivity is reduced under warmer conditions and that rebuilding to historical levels may not be possible. Our goal was to examine the rebuilding potential of winter flounder in the face of regional warming. We integrated winter temperature into a population model to estimate environmentally driven stock–recruitment parameters and projected the stock into the future under different climate and fishing scenarios. The inclusion of winter temperature had minor impacts on the estimates of current abundance, but provided greater understanding of the drivers of recruitment. Projections that included the environment suggest that rebuilding the stock to historical levels is unlikely. The integration of both fishing and the environment has the potential to provide more realistic expectations of future stock status.

Studies of the Trematode Stephanostomum baccatum (Nicoll, 1907): I. The Distribution of the Metacercaria in Eastern Canadian Flounders

1954 ◽  
Vol 11 (6) ◽  
pp. 954-962 ◽  
Author(s):  
R. W. Wolfgang
Keyword(s):  
North American ◽  
Larval Stage ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Passamaquoddy Bay ◽  
The Witch ◽  
Species Being ◽  
Hippoglossoides Platessoides

Stephanostomum baccatum, an acanthocolpid trematode, encysts during its larval stage in eastern Canadian flounders, the most consistently and heavily infected species being the winter flounder, Pseudopleuronectes americanus (Walbaum). The infection is heaviest in Passamaquoddy Bay. Hosts are usually more heavily infected in inshore than in offshore waters. Infections are light in the Bras d'Or Lakes and the northern Gulf of St. Lawrence. Larger fish have heavier infections than smaller fish. S. baccatum infects both European and North American flounders; two of its hosts occur on both sides of the Atlantic: the witch, Glyptocephalus cynoglossus (L.), and the American plaice (European long rough dab), Hippoglossoides platessoides (Fabric.).

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