Commercial harvest of hatchery-reared masu salmon Oncorhynchus masou estimated by a coast-wide sampling program in Hokkaido, northern Japan, and the two-stage sampling schemes of landings

2001 ◽  
Vol 67 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Yasuyuki Miyakoshi ◽  
Mitsuhiro Nagata ◽  
Kei-Ichi Sugiwaka ◽  
Shuichi Kitada
Keyword(s):  
Masu Salmon ◽  
Oncorhynchus Masou ◽  
Two Stage ◽  
Sampling Schemes ◽  
Commercial Harvest ◽  
Sampling Program ◽  
Masu Salmon Oncorhynchus Masou ◽  
Northern Japan

Differential energy allocation of alternative male tactics in masu salmon (Oncorhynchus masou)

2002 ◽  
Vol 59 (11) ◽  
pp. 1717-1723 ◽  
Author(s):  
Yusuke Koseki ◽  
Koji Maekawa
Keyword(s):  
Specific Energy ◽  
Energy Allocation ◽  
Masu Salmon ◽  
Oncorhynchus Masou ◽  
Confounding Effect ◽  
Allocation Pattern ◽  
Mature Parr ◽  
Somatic Energy ◽  
Masu Salmon Oncorhynchus Masou ◽  
Northern Japan

To compare energy allocation to gonad, relative to soma, between alternative male tactics (mature parr and migratory males) in masu salmon (Oncorhynchus masou), we quantified energy contents in somatic and testicular tissues for the two tactics from two lake-run populations (Shikaribetsu Lake and Shumarinai Reservoir) in Hokkaido, northern Japan. Mass-specific testicular energy (kJ·g–1) was lower in migratory males than in mature parr in the Shikaribetsu population, but not in the Shumarinai population. The consistent pattern was observed in somatic energy, suggesting that mass-specific energy reflects population environment rather than inherent allocation pattern. Despite this confounding effect of specific energy, total testicular energy (kJ), relative to total somatic energy, was higher in mature parr in both populations. We suggest that strong sperm competition involved with sneak spawning is responsible for an increased testicular investment in mature parr.

Changes of serum growth hormone and vitellogenin levels during vitellogenesis in female masu salmon Oncorhynchus masou

2000 ◽  
Vol 66 (4) ◽  
pp. 789-791 ◽  
Author(s):  
Haruhisa Fukada ◽  
Naoshi Hiramatsu ◽  
Makiko Kitamura ◽  
Munetaka Shimizu ◽  
Akihiko Hara
Keyword(s):  
Growth Hormone ◽  
Masu Salmon ◽  
Oncorhynchus Masou ◽  
Serum Growth Hormone ◽  
Masu Salmon Oncorhynchus Masou

Molecular cloning of cDNAs encoding two types of gonadotrophin α subunit from the masu salmon, Oncorhynchus masou: construction of specific oligonucleotides for the α1 and α2 subunits

1993 ◽  
Vol 11 (3) ◽  
pp. 265-273 ◽  
Author(s):  
K Gen ◽  
O Maruyama ◽  
T Kato ◽  
K Tomizawa ◽  
K Wakabayashi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Structural Difference ◽  
Structural Features ◽  
Masu Salmon ◽  
Time Interval ◽  
Oncorhynchus Masou ◽  
Α Subunit ◽  
Polymerase Chain ◽  
Fossil Records ◽  
Masu Salmon Oncorhynchus Masou

ABSTRACT Two types of cDNA (GTHα1 and -α2) encoding the α subunits of masu salmon (Oncorhynchus masou) gonadotrophin were cloned by the reverse transcription-polymerase chain reaction for pituitary mRNAs. The nucleotide sequences showed that the GTHα1 cDNA was 380 bp long, encoding 119 amino acids, and that GTHα2 cDNA was 365 bp long, encoding 114 amino acids. The masu salmon α subunit types had a few differences between the sequences, with homologies of 80% (nucleotide sequence) and 72% (amino acid sequence). The structural difference between the α1 and α2 subunits was predicted using hydropathic analysis. The evolutionary interval between masu and chum salmon was estimated to be 4·0 and 2·3 million years by comparing their GTHα1 and -α2 subunits respectively. These time values are roughly consistent with the evolutionary time interval (3·0 million years) estimated from fossil records and an isozyme study. Specific synthetic oligonucleotide probes were constructed and used for genomic Southern blot analyses. The restriction fragment sizes of the GTHα1 and -α2 genes were similar, and when their patterns were compared with those from four other teleosts, each species showed a different pattern from the others, but no difference between their respective α1 and α2 genes. Therefore, the structural features of the GTHα1 and -α2 genes may have diverged in a similar manner in these five teleosts.

Interaction between neuropeptide Y immunoreactive neurons and galanin immunoreactive neurons in the brain of the masu salmon, Oncorhynchus masou

2009 ◽  
Vol 462 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Masafumi Amano ◽  
Noriko Amiya ◽  
Mikiko Hiramatsu ◽  
Takuma Tomioka ◽  
Yoshitaka Oka
Keyword(s):  
Neuropeptide Y ◽  
Masu Salmon ◽  
Oncorhynchus Masou ◽  
The Brain ◽  
Masu Salmon Oncorhynchus Masou
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