Browsing by Author "Toste, Marisa F."
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- Contribution to the study of the genus Predaea (Gigartinales, Nemastomataceae) in the Azores: morphology and life history studies.Publication . Neto, Ana I.; Toste, Marisa F.; Monteiro, Sandra
- Life history and phenology of Colpomenia sinuosa (Mertens ex Roth) Derbès & Solier (Scytosiphonaceae, Phaeophycota) in the Azores.Publication . Toste, Marisa F.; Parente, Manuela I.; Neto, Ana I.; Fletcher, Robert L.
- Life history and phenology of Hydroclathrus clathratus (Scytosiphonaceae, Phaeophyceae) in the Azores.Publication . Toste, Marisa F.; Parente, Manuela I.; Neto, Ana I.; Fletcher, Robert L.Hidroclathrus clathradus is a common specie on the rocky intertidal shores of the island of São Miguel, Azores, mainly in spring and summer. Fertile saccate thaili appear in spring and disappear from late summer onward. Two types of life history were observed in culture: a direct-type and a heteromorphic, monophasic life history. In the direct type, reproductive cells from erect plants collected in the field developed directly into new erect thaili with plurilocular sporangia. In the heteromorphic life-hystory pattern, plurispores from the plurilocular sporangia of the erect thaili developed into filamentous prostate microthalli. These developed unilocular and plurilocular sporangia in both short-day and long-day conditions at 15-22 ºC. Unispores released from the unlocular sporangia developed into saccate thaili, whereas plurispores gave rise to filamentous prostate microthaili.
- Life history and phenology of Hydroclathrus clathratus (Scytosiphonaceae, Phaeophycota) in the Azores.Publication . Toste, Marisa F.; Parente, Manuela I.; Neto, Ana I.; Fletcher, Robert L.
- Life history of Colpomenia sinuosa (Scytosiphonaceae, Phaeophyceae) in the Azores.Publication . Toste, Marisa F.; Parente, Manuela I.; Neto, Ana I.; Fletcher, Robert L.Colpomenia sinuosa (Mertens ex Roth) Derbès and Solier (Scytosiphonaceae, Phaeophyceae) is a common species on the rocky intertidal shores of the Azores, where reproductive gametophytes occur throughout the year. Life-history studies of this species were carried out in culture, and both sexual and asexual reproduction were observed. Anisogamous gametes fused to form zygotes. The zygotes gave rise to a filamentous prostrate sporophyte generation bearing unilocular sporangia, under both short-day and long-day conditions at 15 and 22° C, and to both unilocular and plurilocular sporangia, under the lower temperature condition. Unispores developed into gametophytes, and plurispores gave rise to filamentous sporophytes. Asexual reproduction was carried out by unfused female gametes and asexual plurispores produced from the same gametophyte. Unfused gametes developed into filamentous prostrate sporophytes producing unilocular sporangia in both culture conditions, and unispores released from the sporangia gave rise to gametophytes. Asexual plurispores from field gametophytes, under both culture conditions, developed directly into new gametophytes. The species exhibited three types of life history: a heteromorphic, diplohaplontic; a heteromorphic, monophasic (both with alternation between the erect and filamentous prostrate thalli); and a monomorphic, monophasic.