Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla

dc.contributor.advisorCyrus, Mark Digbyen_ZA
dc.contributor.advisorBolton, John Jen_ZA
dc.contributor.advisorMacey, Brett Men_ZA
dc.contributor.authorDu Plessis, Darren Scotten_ZA
dc.date.accessioned2015-05-06T14:23:29Z
dc.date.available2015-05-06T14:23:29Z
dc.date.issued2014en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractIdentifying the chemical compounds that attract urchins to seaweeds will increase sea urchin aquaculture efficiency as these compounds can be utilized in the production of artificial feeds enhancing their attractiveness and palatability. This study investigated the chemosensory preferences of the tropical sea urchin Tripneustes gratilla for four crude extracts of Ulva as well as Fresh Ulva and an artificial feed. The four crude extracts of Ulva (Methanolic, Ethanolic, Chloroform and Chloroform-Methanol extracts) were tested by pair-wise chemosensory trials in a Y shaped maze. Urchins were significantly deterred by both the Chloroform and Chloroform- Methanol extracts as well as the solvent controls and artificial feed, however T. gratilla was significantly attracted to both the Methanolic and Ethanolic extracts. These two extracts were tested individually against Ulva and the urchins could not distinguish between Ulva and the extracts. When these two extracts were tested against one another it was found that the urchins were significantly attracted to the Methanolic extract. The Methanolic extract was then added to the artificial feed and significantly improved the feeds attractability. This indicates that these extracts, or the compounds which are responsible for this effect, can be incorporated into artificial feeds thereby making them more attractive to the sea urchin. The percentage yield of Ulva that each solvent extracted was different, although only the Ethanolic extract was found to be significantly different from the Chloroform and Chloroform-Methanol extracts. Future studies are needed to examine the chemical composition of these specific chemosensory compounds. By incorporating these attractive extracts into artificial feeds, South Africa can potentially improve the cultivation success of T. gratilla therefore expanding the economy of the local aquaculture industry through the export of this highly valued seafood product.en_ZA
dc.identifier.apacitationDu Plessis, D. S. (2014). <i>Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/12766en_ZA
dc.identifier.chicagocitationDu Plessis, Darren Scott. <i>"Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2014. http://hdl.handle.net/11427/12766en_ZA
dc.identifier.citationDu Plessis, D. 2014. Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Du Plessis, Darren Scott AB - Identifying the chemical compounds that attract urchins to seaweeds will increase sea urchin aquaculture efficiency as these compounds can be utilized in the production of artificial feeds enhancing their attractiveness and palatability. This study investigated the chemosensory preferences of the tropical sea urchin Tripneustes gratilla for four crude extracts of Ulva as well as Fresh Ulva and an artificial feed. The four crude extracts of Ulva (Methanolic, Ethanolic, Chloroform and Chloroform-Methanol extracts) were tested by pair-wise chemosensory trials in a Y shaped maze. Urchins were significantly deterred by both the Chloroform and Chloroform- Methanol extracts as well as the solvent controls and artificial feed, however T. gratilla was significantly attracted to both the Methanolic and Ethanolic extracts. These two extracts were tested individually against Ulva and the urchins could not distinguish between Ulva and the extracts. When these two extracts were tested against one another it was found that the urchins were significantly attracted to the Methanolic extract. The Methanolic extract was then added to the artificial feed and significantly improved the feeds attractability. This indicates that these extracts, or the compounds which are responsible for this effect, can be incorporated into artificial feeds thereby making them more attractive to the sea urchin. The percentage yield of Ulva that each solvent extracted was different, although only the Ethanolic extract was found to be significantly different from the Chloroform and Chloroform-Methanol extracts. Future studies are needed to examine the chemical composition of these specific chemosensory compounds. By incorporating these attractive extracts into artificial feeds, South Africa can potentially improve the cultivation success of T. gratilla therefore expanding the economy of the local aquaculture industry through the export of this highly valued seafood product. DA - 2014 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2014 T1 - Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla TI - Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla UR - http://hdl.handle.net/11427/12766 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/12766
dc.identifier.vancouvercitationDu Plessis DS. Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2014 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/12766en_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.otherAquacultureen_ZA
dc.titleChemosensory properties of different Ulva extracts and their effects on Tripneustes gratillaen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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