No.74 (March,2009)
No.74 (March,2009)
A－425 Masashi NATSUME ,Yasuo MORI and Kouji TUJI
Migratory origin of Pacific saury, Cololabis saira, caught by drift net fishing in summer in the eastern waters off Hokkaido.
In order to elucidate the migratory origin of Pacific saury, Cololabis saira, caught by drift net fishing in summer in the eastern waters off Hokkaido, we examined the biological characteristics of the Pacific saury caught by stick-held dip net fishing and drift net fishing in the southeastern waters of Hokkaido, and specimens collected during a research vessel survey of the waters extending between Tohoku and east Hokkaido. Pacific saury caught by drift net fishing was characterized by a high parasitism rate of Caligus macarovi, low lipid content, and advanced maturity. These characteristics were similar to those determined by the research vessel survey but differed from those determined from specimens caught by stick-held dip net fishing. These results indicate that Pacific saury caught by drift net fishing originated from a shoal of Pacific saury migrating northward along northeastern Honshu between spring and summer.
In order to elucidate the migratory origin of Pacific saury, Cololabis saira, caught by drift net fishing in summer in the eastern waters off Hokkaido, we examined the biological characteristics of the Pacific saury caught by stick-held dip net fishing and drift net fishing in the southeastern waters of Hokkaido, and specimens collected during a research vessel survey of the waters extending between Tohoku and east Hokkaido. Pacific saury caught by drift net fishing was characterized by a high parasitism rate of Caligus macarovi, low lipid content, and advanced maturity. These characteristics were similar to those determined by the research vessel survey but differed from those determined from specimens caught by stick-held dip net fishing. These results indicate that Pacific saury caught by drift net fishing originated from a shoal of Pacific saury migrating northward along northeastern Honshu between spring and summer.
A－426 Kazuhiko ITAYA, Takahiro Takashima and Masaki Mitsuhashi
Age and growth of flathead flounder Hippoglossoides dubius in the Sea of Japan off western Hokkaido
Age and growth of flathead flounder Hippoglossoides dubius in western Hokkaido was investigated. The samples were collected from July to November in 2007 using bottom trawl gears of R.V. Oyashio Maru. Ages were estimated from the number of opaque zones in otoliths, on the basis of the birthday as July 1. The von Bertalanffy growth formula, which were fitted to total length TL(t) or body weight BW(t) at age t, were TL(t)=541(1-e -0.13(t+0.94)) for female, TL(t)=326(1-e -0.28(t+0.48)) for male, BW(t)=1936(1-e -0.11 (t+0.86))3 for female and BW(t)=319(1-e -0.28 (t+0.31)) 3 for male. Flathead flounder in western Hokkaido grows greater than in other area.
Age and growth of flathead flounder Hippoglossoides dubius in western Hokkaido was investigated. The samples were collected from July to November in 2007 using bottom trawl gears of R.V. Oyashio Maru. Ages were estimated from the number of opaque zones in otoliths, on the basis of the birthday as July 1. The von Bertalanffy growth formula, which were fitted to total length TL(t) or body weight BW(t) at age t, were TL(t)=541(1-e -0.13(t+0.94)) for female, TL(t)=326(1-e -0.28(t+0.48)) for male, BW(t)=1936(1-e -0.11 (t+0.86))3 for female and BW(t)=319(1-e -0.28 (t+0.31)) 3 for male. Flathead flounder in western Hokkaido grows greater than in other area.
A－427 Kohji EBITANI , Masanao NARITA ,Hiroyuki KODAMA ,Masaki AKINO ,Tadaaki TAKEDA and Takuma IMAMURA
Changes in chemical composition and free amino acid of "Yamaduke" pickled pink salmon during processing
"Yamaduke" pickled pink salmon (Onchorhynchus gorbuscha) were analyzed to find how difference in their lipid content before pickling and pickling salt affected salt permeation and ripening. Before the analyses, pink salmon from the Sea of Okhotsk had been surveyed to find their characteristics as a raw material.
When pink salmon with a high lipid content or “funsaien” is used, "Yamaduke" pickled salmon tended to come out low in salt content. The salting increased free amino acid content to 1.2-1.5 times higher than that of the non-salted pink salmon, but differences in free amino acid content due to different raw materials or different salts were not pronounced. During the air drying, free amino acid content increased with the number of drying days, reaching 1.6 times as high as the level of the raw material on day seven and 1.8 times on day 14. With respect to amino acid composition, taurine and histidine levels decreased after the salting but levels of other amino acids, lysine and arginine in particular, markedly increased. The air-drying increased levels of all amino acids except taurine and hydroxyproline. The air-drying also increased the level of glutamic acid, an umami component, to as high as 1.4 times the level right after the desalting, although glutamic acid content increased only slightly during the salting.
"Yamaduke" pickled pink salmon (Onchorhynchus gorbuscha) were analyzed to find how difference in their lipid content before pickling and pickling salt affected salt permeation and ripening. Before the analyses, pink salmon from the Sea of Okhotsk had been surveyed to find their characteristics as a raw material.
When pink salmon with a high lipid content or “funsaien” is used, "Yamaduke" pickled salmon tended to come out low in salt content. The salting increased free amino acid content to 1.2-1.5 times higher than that of the non-salted pink salmon, but differences in free amino acid content due to different raw materials or different salts were not pronounced. During the air drying, free amino acid content increased with the number of drying days, reaching 1.6 times as high as the level of the raw material on day seven and 1.8 times on day 14. With respect to amino acid composition, taurine and histidine levels decreased after the salting but levels of other amino acids, lysine and arginine in particular, markedly increased. The air-drying increased levels of all amino acids except taurine and hydroxyproline. The air-drying also increased the level of glutamic acid, an umami component, to as high as 1.4 times the level right after the desalting, although glutamic acid content increased only slightly during the salting.
A－428 Koji TSUJI，Akiyuki SATO，Hiromi KANEKO，Genta YASUNAGA ，Yoshihiro FUJISE and Hiroshi NOMATA
Comparison of physiologically significant imidazole dipeptides in cetaceans sampled in Japanese whale research （Short Paper）