著者

Kohtaroh Shutoh Mitsuru Usuba Hiroki Yamagishi Yushi Fujita Takashi Shiga

出版者

The Japanese Society for Plant Systematics

雑誌

Acta Phytotaxonomica et Geobotanica (ISSN:13467565)

巻号頁・発行日

vol.71, no.1, pp.33-44, 2020-02-29 (Released:2020-03-17)

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Potamogeton ×angustifolius (P. gramineus × P. lucens) was newly recorded in Japan from a pond in Tsugaru-shi, Aomori Prefecture. The hybrid nothospecies was identified based on morphological observations and measurements, molecular analyses using cloned nuclear adhA gene and chloroplast rpl20–rps12 intergenic spacer, and pollen viability. The putative hybrid had morphological traits intermediate between P. gramineus and P. lucens, nuclear haplotypes matching those of the two parental lineages, and lower pollen viability than P. lucens (not compared with P. gramineus). The maternal lineage of the hybrid was presumed to be P. gramineus, based on chloroplast sequences. The hybrid characteristically shows well-branched stems in the upper part of shoots, as in P. gramineus, and both clearly petiolate and sessile submerged leaves with distinctive netted venation. Similar plants were collected in the 1980s from a ditch near the pond, suggesting that the hybrid may have been present for more than 30 years in this area.

著者

山岸 大樹 Hiroki Yamagishi

出版者

同志社大学グローバル・スタディーズ学会

雑誌

同志社グローバル・スタディーズ = Journal of global studies (ISSN:21859396)

巻号頁・発行日

vol.12, pp.169-190, 2021

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論文

著者

Takashi Yamamoto Hiroyoshi Kohno Akira Mizutani Hanako Sato Hiroki Yamagishi Yutaka Fujii Miku Murakoshi Ken Yoda

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.16, no.1, pp.17-22, 2017 (Released:2017-03-01)

参考文献数

42

被引用文献数

14

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There is increasing evidence showing that wind velocity affects the flight and foraging behavior of seabirds; however, few studies have examined these effects on seabirds inhabiting tropical oceans where lighter wind conditions usually prevail. The Brown Booby Sula leucogaster is an example of a tropical seabird with relatively low wing loading; strong wind conditions may be expected to impede the stability of their flight. We examined how different wind conditions affected the duration and flying behavior of Brown Booby fledglings during foraging trips by means of direct observation of nest attendance and by attaching video loggers to birds. The duration of foraging trips by fledglings decreased with increasing wind speed, and during flight, the body rotation of fledglings became greater with increasing wind speed. As expected, fledglings were buffeted by strong winds due to their relative inexperience in flight combined with their low wing loading. Fledglings were probably forced to flap against strong winds in order to adjust the stability of their bodies, offsetting the efficient use of wind for gliding. Furthermore, the height at which fledglings flew fluctuated more at higher wind velocities, which may have constrained their detection and capture of prey. In conclusion, our results indicate that the aerodynamic performance of Brown Booby fledglings is impaired by strong wind conditions, leading to poor flight stability and potentially reduced prey detection.