scholarly journals Growth and survival of winter flounder ( Pseudopleuronectes americanus ) larvae reared on different photoperiod regimes from hatch to metamorphosis

2020 ◽  
Vol 51 (6) ◽  
pp. 2314-2321 ◽  
Author(s):  
Matthew K. Litvak ◽  
Vahid Zadmajid ◽  
Ian A. E. Butts
Keyword(s):  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Growth And Survival

scholarly journals Influence of the timing of weaning on growth and survival of juvenile winter flounder (Pseudopleuronectes americanus)

2018 ◽  
Vol 96 (12) ◽  
pp. 1291-1298 ◽  
Author(s):  
M. Bélanger ◽  
F. Turcotte ◽  
R. Tremblay ◽  
Y. Lambert ◽  
M.K. Litvak ◽  
...  
Keyword(s):  
Larval Stage ◽  
Brachionus Plicatilis ◽  
Artemia Salina ◽  
Winter Flounder ◽  
Nutritional Deficiencies ◽  
Pseudopleuronectes Americanus ◽  
Growth And Survival ◽  
Larval Stages ◽  
Live Feed ◽  
Trophic Markers

Metamorphosis is a critical developmental stage that presents particular challenges in fish aquaculture. The sharp increase in mortality that accompanies this transformation has often been attributed to nutritional deficiencies. Providing live feed (the rotifer Brachionus plicatilis Müller, 1786 and the brine shrimp Artemia salina (Linnaeus, 1758)) during the larval stages is costly and labour intensive, which explains why much effort has been put on early weaning. However, previous observations in winter flounder (Pseudopleuronectes americanus (Walbaum, 1792)) indicate that juveniles weaned after settlement had better survival than those weaned at the larval stage. In this study, we tested whether late weaning (at settlement (W0) and groups maintained on co-feeding for 1 month (W1), two months (W2), or 3 months (W3) after settlement) could improve juvenile survival and lipid composition. Our results demonstrated that maintaining co-feeding beyond the larval stage was essential for after-settlement survival. Juveniles co-fed until 90 days after settlement were 32.5% heavier. Analyses of fatty acid trophic markers suggested that juveniles preferentially fed on enriched rotifers rather than inert food. No pigmentation or fin erosion problems were observed in any of the weaning treatments, which indicates good rearing conditions.

The Winter Flounder (Pseudopleuronectes americanus) in Long Pond, Conception Bay, Newfoundland

1971 ◽  
Vol 28 (8) ◽  
pp. 1153-1165 ◽  
Author(s):  
V. S. Kennedy ◽  
D. H. Steele
Keyword(s):  
Food Intake ◽  
Growth Rates ◽  
Plant Material ◽  
Early Growth ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Food Items ◽  
Fish Remains ◽  
Males And Females ◽  
Conception Bay

Monthly samples of winter flounder taken in Long Pond from November 1962 to October 1963 indicated that the flounder moved into deeper water (7–10 m) during the summer and returned to shallow water (1–2 m) from September to June. These movements corresponded to the end of the spawning season and the ripening of the gonads respectively. Spawning occurred from March until early June, most of it in May and early June. Most males were mature at age 6 and most females at age 7. Fifty percent of the males and females were mature at 21 and 25 cm respectively. The growth rates of the males and females were similar until the age of 8, after which the females apparently outgrew the males. Early growth and fecundity were similar to those reported for other areas. No feeding took place in December or January but the flounder fed in March and continued to feed throughout the summer; food intake decreased in the fall. They were omnivorous and the type of food eaten varied with the locality. Polychaetes, plant material, and molluscs were the most common food items throughout the year. Capelin eggs and fish remains were found only during a few months of the year but were eaten in great quantities.

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