舞鶴湾のアキヨレモク群落に４㎡の永久コドラートを設定し，その中の個体を識別 し，本種群落の動態（密度や全長組成の変化，加入や死亡）を52ヵ月にわたって調べた。個体密度は調査期間中に10～30個体/㎡で変動した。月間死亡率は，台風時の26％が最高であっ たがそれ以外では15％未満であった。また，特定の時期に死亡が増加する傾向はなかった。 幼体は秋から冬にかけて発生し，その個体数は年変動が大きく，まったく出現しない年から 最大で50.3個体/㎡も出現した年があった。幼体が多く出現した後には，群落の個体密度が増加した。当歳個体のうち半数以上は成熟可能なサイズに達していた。

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Carposporelings of Gracilaria blodgettii Harvey were exposed to different temperature (20℃, 25℃, 30℃ and 35℃), salinity (20‰, 25‰, 30‰ and 35‰) and irradiance (60 µmol photons m^-2s^-1 and 100µmol photons m^-2s^-1) levels to determine effects on growth and photosynthetic performance using a series of factorial experiments. Growth was significantly affected by variations in temperature and irradiance levels with highest growth rates obtained at 25℃ (13.1% d^-1) and 100µmol photons m^-2s^-1 (12.7% d^-1). No significant difference was found at all salinity levels tested. Photosynthesis-irradiance (P-I) parameters were directly proportional with increasing temperature. Significantly higher net photosynthesis (Pmax) was obtained at 30℃ and 35℃ than at 25℃ and 20℃ but were complemented with higher respiration rates (1.19 for 30℃ and 1.32 for 35℃) ( p < 0.05). The high photosynthetic efficiency (α) which suggests its ability to maximize low-light conditions was also significantly higher at 25℃ to 35℃ (0.04 to 0.05) than at 20℃ ( p < 0.05). This is further shown by the low compensation point photon fluxes (Ic) (19-27µmol photons m^-2s^-1) and saturation photon fluxes (110-159µmol photons m^-2s^-1). Salinity did not produce significant differences on the photosynthetic responses of the seaweed. This study concludes good culture conditions for Gracilaria blodgettii at 25℃ and 100µmol photons m^-2s^-1 based on high growth rates and high photosynthetic rates with low respiration.

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Morphological studies of the Porphyra akasakae Miura (Rhodophyta, Bangiales) collected on December 14, 2005 were reported from Iwaizaki, Miyagi Prefecture, northern Pacific coasts of Honshu, Japan. It has been considered that P. angusta sensu Kurogi and P. angusta f. sanrikuensis Kurogi were synonyms of Porphyra akasakae Miura. Zygotospores and conchospores were cultured at 10-30 ℃ and 60μmol m^-2s^-1 under 14L: 10D and 10L:14D. Conchospores germinated and grew to normal shape blades at 10-20℃. However, the germlings did not grow to normal size at 25℃. The maturation of male and female blades occurred at 20℃, and the spermatia in the male blade and zygotospores in the female blades were produced after 10 - 12 weeks in culture, and mother cells divided into 128 (a/4, b/4, c/8) sprematia and 8 (a/2, b/2, c/2) zygotospores, respectively. The conchocelis grew rapidly at 25℃ and 14L:10D, and the conchospores were released 3 weeks after zygotospore germination. This species has been known to have dioecious or monoecious blade, however, in this culture, blades were mostly dioecious, and about 7 % of blades in cultures were monoecious, and spermatangia or zygotospores produced and divided at the upper or lower portion of the blade. The life cycle of this species was different from the previous reports and revealed to be P. dentata-type.

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