First report of growth rate of juvenile chum salmon Oncorhynchus keta captured in the Sea of Okhotsk offshore

2018 ◽  
Vol 66 (1) ◽  
pp. 155-159 ◽  
Author(s):  
Kentaro Honda ◽  
Tatsuya Kawakami ◽  
Toshihiko Saito ◽  
Shigehiko Urawa
Keyword(s):  
Growth Rate ◽  
Sea Of Okhotsk ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
First Report ◽  
The Sea Of Okhotsk ◽  
Chum Salmon Oncorhynchus Keta ◽  
Juvenile Chum Salmon

Relationship between Otolith Microstructure and the Growth of Juvenile Chum Salmon (Oncorhynchus keta) under Different Prey Rations

1984 ◽  
Vol 41 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Eric C. Volk ◽  
Robert C. Wissmar ◽  
Charles A. Simenstad ◽  
Douglas M. Eggers
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Harpacticoid Copepod ◽  
Fish Growth ◽  
Oncorhynchus Keta ◽  
Otolith Microstructure ◽  
Increment Width ◽  
Chum Salmon Oncorhynchus Keta ◽  
Otolith Increment ◽  
Juvenile Chum Salmon

Effects of different prey taxa and daily ration levels on fish growth and the relationship between fish growth rate and mean otolith increment width were investigated for juvenile chum salmon (Oncorhynchus keta) in saltwater aquaria. Growth was positively correlated with ration, and food conversion efficiency was much higher for fish fed the harpacticoid copepod, Tigriopus californicus, than either the calanoid copepod, Pseudocalanus minutas, or the gammarid amphipod, Paramoera mohri. Otolith increments were produced daily for at least the first 160 d after hatching and there was a direct relationship between mean daily otolith increment width and fish growth rate. These results illustrate the possibility that otolith microstructure recapitulates juvenile chum growth histories during estuarine residence.

Growth of Juvenile Chum Salmon (Oncorhynchus keta) Under Different Feeding Regimes

1969 ◽  
Vol 26 (6) ◽  
pp. 1631-1645 ◽  
Author(s):  
R. J. LeBrasseur
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Rate Of Growth ◽  
Total Length ◽  
Chum Salmon Oncorhynchus Keta ◽  
Feeding Regimes ◽  
Size Groups ◽  
Juvenile Chum Salmon ◽  
The Mean

Juvenile chum salmon were fed on six different concentrations of size-selected zooplankton for 8 weeks. Zooplankton were caught daily and sorted through sieves into size-groups roughly as follows: 6–20 mm total length, mainly euphausiids; 2.5–4.5 mm, mainly copepods; and ≤ 1.5 mm, mainly small copepods. The rate of growth in weight of the fish was found to be dependent upon the concentration of the ration. Fish which were offered no food lost weight, and fish which were offered excess food increased in weight by 5.4% per day. The mean growth rate of the fish held on fixed rations ranged from 2.2 to 5.7% per day and was found to be independent of the type of prey. Electivity experiments showed that all the fish selected copepods 1.6–4.5 mm long in proportion to their abundance and rejected copepods ≤ 1.5 mm. The euphausiids were selected only by fish which had previously fed on euphausiids. The effect of variations in the availability of prey is discussed.

scholarly journals Neural Stem Cells/Neuronal Precursor Cells and Postmitotic Neuroblasts in Constitutive Neurogenesis and After ,Traumatic Injury to the Mesencephalic Tegmentum of Juvenile Chum Salmon, Oncorhynchus keta

2020 ◽  
Vol 10 (2) ◽  
pp. 65
Author(s):  
Pushchina ◽  
Kapustyanov ◽  
Varaksin
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Progenitor Cells ◽  
Chum Salmon ◽  
Precursor Cells ◽  
Oncorhynchus Keta ◽  
Neuronal Precursor ◽  
Chum Salmon Oncorhynchus Keta ◽  
Neuronal Precursor Cells ◽  
Juvenile Chum Salmon

The proliferation of neural stem cells (NSCs)/neuronal precursor cells (NPCs) and the occurrence of postmitotic neuroblasts in the mesencephalic tegmentum of intact juvenile chum salmon, Oncorhynchus keta, and at 3 days after a tegmental injury, were studied by immunohistochemical labeling. BrdU+ constitutive progenitor cells located both in the periventricular matrix zone and in deeper subventricular and parenchymal layers of the brain are revealed in the tegmentum of juvenile chum salmon. As a result of traumatic damage to the tegmentum, the proliferation of resident progenitor cells of the neuroepithelial type increases. Nestin-positive and vimentin-positive NPCs and granules located in the periventricular and subventricular matrix zones, as well as in the parenchymal regions of the tegmentum, are revealed in the mesencephalic tegmentum of juvenile chum salmon, which indicates a high level of constructive metabolism and constitutive neurogenesis. The expression of vimentin and nestin in the extracellular space, as well as additionally in the NSCs and NPCs of the neuroepithelial phenotype, which do not express nestin in the control animals, is enhanced during the traumatic process. As a result of the proliferation of such cells in the post-traumatic period, local Nes+ and Vim+ NPCs clusters are formed and become involved in the reparative response. Along with the primary traumatic lesion, which coincides with the injury zone, additional Nes+ and Vim+ secondary lesions are observed to form in the adjacent subventricular and parenchymal zones of the tegmentum. In the lateral tegmentum, the number of doublecortin-positive cells is higher compared to that in the medial tegmentum, which determines the different intensities and rates of neuronal differentiation in the sensory and motor regions of the tegmentum, respectively. In periventricular regions remote from the injury, the expression of doublecortin in single cells and their groups significantly increases compared to that in the damage zone.

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