A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales)

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dc.contributor.authorAnderson, Robert Jamesen_ZA
dc.date.accessioned2015-12-08T06:59:57Z
dc.date.available2015-12-08T06:59:57Z
dc.date.issued1982en_ZA
dc.descriptionBibliography: leaves 212-232.en_ZA
dc.description.abstractSeveral aspects of the biology of Desmarestia firma (C.Ag.) Skottsb., a common understorey alga in western Cape (Southern Africa) kelp beds, are investigated. The life-history of this species is described from culture. Zoospores from unilocular sporangia give rise to separate filamentous male and female gametophytes. Male gametophytes bear flask-shaped antheridia, each containing a single antherozooid. Female gametophytes bear club-shaped oogonia, each producing one or perhaps more eggs. Trichothallic sporophytes are fused to the female gametophytes. Specimens were cultured to a stage where they produced rhizoids and cortication became apparent. This is the first description of the life-history of a branched, ligulate Desmarestia species, and refutes the suggestion that in oppositely branched species, gametophytes are monoecious. Nomenclatural problems associated with D. firma are discussed, and the taxonomic relationships of D. firma and closely related species are investigated. Results show varying degrees of morphological overlap between this entity and certain others from North West America, South America and Morocco. Microscopic examinations show that sporophytes from New Zealand, Gough Island, South America and N.W. America have the same reproductive anatomy as D. firma, i.e. with sporangia scattered among, and similar in size and shape to the cells of the outer cortical layer. Material from the South Orkney Islands shows sporangia interspersed with sterile paraphyses and arranged in an elevated sorus. The taxonomic implications of these results are discussed, and the name D. firma is provisionally retained for the Southern African entity.en_ZA
dc.identifier.apacitationAnderson, R. J. (1982). <i>A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales)</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/15675en_ZA
dc.identifier.chicagocitationAnderson, Robert James. <i>"A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales)."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1982. http://hdl.handle.net/11427/15675en_ZA
dc.identifier.citationAnderson, R. 1982. A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales). University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Anderson, Robert James AB - Several aspects of the biology of Desmarestia firma (C.Ag.) Skottsb., a common understorey alga in western Cape (Southern Africa) kelp beds, are investigated. The life-history of this species is described from culture. Zoospores from unilocular sporangia give rise to separate filamentous male and female gametophytes. Male gametophytes bear flask-shaped antheridia, each containing a single antherozooid. Female gametophytes bear club-shaped oogonia, each producing one or perhaps more eggs. Trichothallic sporophytes are fused to the female gametophytes. Specimens were cultured to a stage where they produced rhizoids and cortication became apparent. This is the first description of the life-history of a branched, ligulate Desmarestia species, and refutes the suggestion that in oppositely branched species, gametophytes are monoecious. Nomenclatural problems associated with D. firma are discussed, and the taxonomic relationships of D. firma and closely related species are investigated. Results show varying degrees of morphological overlap between this entity and certain others from North West America, South America and Morocco. Microscopic examinations show that sporophytes from New Zealand, Gough Island, South America and N.W. America have the same reproductive anatomy as D. firma, i.e. with sporangia scattered among, and similar in size and shape to the cells of the outer cortical layer. Material from the South Orkney Islands shows sporangia interspersed with sterile paraphyses and arranged in an elevated sorus. The taxonomic implications of these results are discussed, and the name D. firma is provisionally retained for the Southern African entity. DA - 1982 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1982 T1 - A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales) TI - A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales) UR - http://hdl.handle.net/11427/15675 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/15675
dc.identifier.vancouvercitationAnderson RJ. A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales). [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1982 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/15675en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherBotanyen_ZA
dc.titleA biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales)en_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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