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Your search keyword '"Yoshinaga, Tatsuki"' showing total 222 results
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222 results on '"Yoshinaga, Tatsuki"'

5. Circulation

Author

Yoshinaga, Tatsuki, Yoshizaki, Goro, Editor-in-Chief, Kaneko, Toyoji, Series Editor, Kurokura, Hisashi, Series Editor, Tokai, Tadashi, Series Editor, Tsukamoto, Katsumi, editor, Kuroki, Mari, editor, and Watanabe, Soichi, editor

Published
2023
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7. Leptin gene expression in the brain is associated with the physiological onset of estivation in western sand lance Ammodytes japonicus.

Author

Amiya, Noriko, Nakano, Nayu, Tanaka, Chikaya, Hibino, Shizuha, Takakura, Ryota, Amano, Masafumi, and Yoshinaga, Tatsuki

Subjects
PEPTIDE hormones, MARINE fishes, GENE expression, APPETITE disorders, LEPTIN
Abstract

Dormancy is an essential ecological characteristic for the survival of organisms that experience harsh environments. Although factors that initiate dormancy vary, suppression or cessation of feeding activities are common among taxa. To distinguish between extrinsic and intrinsic causes of metabolic reduction, we focused on estivation, which occurs in summer when the feeding activity is generally enhanced. Sand lances (genus Ammodytes) are a unique marine fish with a long estivation period from early summer to late autumn. In the present study, we aimed to elucidate the control mechanisms of estivation in western sand lance (A. japonicus), and firstly examined behavioral changes in 8 months including a transition between active and dormant phases. We found that swimming/feeding behavior gradually decreased from June, and completely disappeared by late August, indicating all individuals had entered estivation. Next, we focused on leptin, known as a feeding suppression hormone in various organisms, and examined leptin‐A gene (AjLepA) expression in the brain that may regulate the seasonal behavioral pattern. AjLepA expression decreased after 7 days of fasting, suggesting that leptin has a function to regulate feeding in this species. The monthly expression dynamics of AjLepA during the feeding (active) and non‐feeding (estivation) periods showed that the levels gradually increased with the onset of estivation and reached its peak when all the experimental fish had estivated. The present study suggests that the suppression of feeding activity by leptin causes shift in the physiological modes of A. japonicus before estivation. Research highlights: Sand lance spends in sand for more than half a year without feeding, a unique dormancy among teleosts called estivationLeptin, a peptide hormone, was found to be involved in appetite suppression in brain and work to exert the onset of estivation [ABSTRACT FROM AUTHOR]

Published
2024
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10. Aging and Lifespan in the Rotifer

Author

Kaneko, Gen, Yoshinaga, Tatsuki, Aida, Katsumi, Editor-in-chief, Kaneko, Toyoji, Series editor, Kurokura, Hisashi, Series editor, Tokai, Tadashi, Series editor, Hagiwara, Atsushi, editor, and Yoshinaga, Tatsuki, editor

Published
2017
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22. Seasonal changes in species composition of glass eels of the genus Anguilla (Teleostei: Anguillidae) recruiting to the Cagayan River, Luzon Island, the Philippines

Author

Aoyama, Jun, Yoshinaga, Tatsuki, Shinoda, Akira, Shirotori, Fumiaki, Yambot, Apolinario V., and Han, Yu-San

Subjects
Luzon Island -- Natural history, Animal populations, Eels, Earth sciences, Science and technology
Abstract

Abstract: Tropical species of anguillid glass eels have recently been exploited to be a substitute for the commercially important Anguilla japonica or A. anguilla, so information about their life histories [...]

Published
2015
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35. Offshore spawning for the newly discovered anguillid species Anguilla luzonensis (Teleostei: Anguillidae) in the Western North Pacific

Author

Kuroki, Mari, Miller, Michael J., Aoyama, Jun, Watanabe, Shun, Yoshinaga, Tatsuki, and Tsukamoto, Katsumi

Subjects
Luzon Island -- Natural resources, Marine biology -- Research, Spawning -- Observations, Earth sciences, Science and technology
Abstract

A new anguillid eel species, Anguilla luzonensis, was recently discovered on Luzon Island of the northern Philippines, but little is known about its life history. DNA identification was used to determine that five leptocephali of this species (29.2-51.2 mm) were collected offshore in the western North Pacific (13°-17.5° N, 125°-141° E) in April, June, and July between 2002 and 2009. One leptocephalus was caught west of Luzon and four were close to the spawning areas of Anguilla japonica and Anguilla marmorata. Otolith microstructure showed that the leptocephali were up to 103-138 days old. Glass eels from northern Luzon in previous studies that were thought to be Anguilla celebesensis now appear likely to have been A. luzonensis, and they were estimated by otolith analysis to have long larval durations similar to those of A. marmorata. Estimated hatching dates of these glass eels and the A. luzonensis leptocephali were both in the February to May season. Offshore presence of leptocephali of A. luzonensis and direction of ocean currents suggest that this species migrates offshore to spawn in the North Equatorial Current., After Ege (1939) and Castle and Williamson (1974) established that there were apparently only 18 species or subspecies of the genus Anguilla in the world, it had been 70 yr [...]

Published
2012
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36. Genetic identification and morphology of naturally spawned eggs of the Japanese eel Anguilla japonica collected in the western North Pacific

Author

Yoshinaga, Tatsuki, Miller, Michael J., Yokouchi, Kazuki, Otake, Tsuguo, Kimura, Shingo, Aoyama, Jun, Watanabe, Shun, Shinoda, Akira, Oya, Machiko, Miyazaki, Sachie, Zenimoto, Kei, Sudo, Ryusuke, Takahashi, Tetsuya, Ahn, Hyojin, Manabe, Ryotaro, Hagihara, Seishi, Morioka, Hiroshi, Itakura, Hikaru, Machida, Masamichi, Ban, Kazuyuki, Shiozaki, Mayu, Ai, Bunpei, and Tsukamoto, Katsumi

Published
2011
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37. Evaluation of the larval distribution and migration of the Japanese eel in the western North Pacific

Author

Shinoda, Akira, Aoyama, Jun, Miller, Michael J., Otake, Tsuguo, Mochioka, Noritaka, Watanabe, Shun, Minegishi, Yuki, Kuroki, Mari, Yoshinaga, Tatsuki, Yokouchi, Kazuki, Fukuda, Nobuto, Sudo, Ryusuke, Hagihara, Seishi, Zenimoto, Kei, Suzuki, Yuzuru, Oya, Machiko, Inagaki, Tadashi, Kimura, Shingo, Fukui, Atsushi, Lee, Tae Won, and Tsukamoto, Katsumi

Published
2011
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