Chemiese kommunikasie van die Suid-Afrikaanse gordelakkedisse

Louw, Stefan (2003-12)

Thesis (PhD)--Stellenbosch University, 2003.

Thesis

ENGLISH ABSTRACT: The sungazer, Cordylus giganteus, is an endangered lizard species belonging to the family Cordylidae. It has been speculated that the function of semiochemical communication is performed by two types of skin glands, the femoral glands and the generation glands, which are also found in this family of lizards. Other skin glands and also the cloacal glands are further possible sources of semiochemicals. The investigation of these potential sources of chemical messages in C. giganteus, served as a starting point towards a better understanding of the chemical communication of lizard species belonging to the family Cordylidae. In continuation of this study the femoral gland secretion of the Cape girdled lizard, C. cordylus, was also investigated. Gas chromatography, low resolution GC-MS, GC-HR-MS, MO-TMS derivatisation and retention time comparison were used as analytical techniques in the chemical characterization of the femoral and generation gland secretions of C. giganteus and the femoral gland secretion of C. cordylus. Some compounds were not identified because of their low concentration in the secretions and/or mass spectra could not be obtained for pure compounds because of co-elution with other compounds. Compounds identified in the femoral gland secretion include the following: Carboxylic acids - saturated and unsaturated Alcohols Ketones Aldehydes - saturated and unsaturated Esters - saturated and unsaturated Hydrocarbons - saturated and unsaturated Nitriles Amides - saturated and unsaturated y-Lactones Squalene u-Tocopherol Steroids Quantitative analysis of the femoral and generation gland secretions of a number of sungazers indicated distinct differences between the secretions of males and females (in the case of the femoral gland secretions), but no apparent trend could be found in the differences between the femoral and generation gland secretions of individual lizards of the same gender. Qualitative seasonal differences were however observed in the femoral gland secretions of all individuals of C giganteus.

AFRIKAANSE OPSOMMING: Die ouvolk, Cordylus giganteus, is 'n bedreigde akkedisspesie van die familie Cordilidae. Daar is gespekuleer dat twee soorte velkliere wat by hierdie familie akkedisse voorkom, naamlik die femorale- en generasiekliere, betrokke is by semiochemiese kommunikasie van hierdie diere. Ander velkliere, asook die kliere in die akkedisse se kloaka, is ook potensiele bronne van semiochemiese verbindings. Die bestudering van hierdie potensiele bronne van chemiese boodskappe by C. giganteus is as 'n beginpunt gebruik om die semiochemiese kommunikasie van die akkedisse van die familie Cordilidae beter te verstaan. Ter uitbreiding van hierdie studie is die femorale klierafskeiding van die Kaapse gordelakkedis, C. cordylus, ook ondersoek. Die femorale en generasieklierafskeidings van C. giganteus en die femorale klierafskeidings van C. cordylus is chemies gekarakteriseer deur van analitiese tegnieke, naamlik gaschromatografie, lae resolusie GC-MS, GC-HR-MS, MO- TMS derivatisering en retensietydvergelyking, gebruik te maak. Talle verbindings is nie geidentifiseer nie omdat hulle in 'n baie lae konsentrasie in die afskeidings voorkom, en/of saam met ander komponente elueer, wat veroorsaak dat daar nie massaspektra vir hierdie suiwer komponente verkry kon word nie. Verbindingstipes wat in die afskeidings voorkom, sluit die volgende in: Karboksielsure - versadig en onversadig Alkohole Ketone Aldehiede - versadig en onversadig Esters - versadig en onversadig Koolwaterstowwe - versadig en onversadig Nitriele Amiede - versadig en onversadig y-Laktone Skwaleen a-Tocopherol Steroiede Kwantitatiewe analises van die femorale en generasieklierafskeidings van verskeie ouvolk akkedisse het getoon dat daar duidelike kwantitatiewe verskille tussen die afskeidings van mannetjies en wyfies is (in die geval van die femorale klierafskeidings), maar dat daar geen duidelike patroon in die verskille tussen die femorale en generasieklierafskeidings van individuele akkedisse van dieselfde geslag is rue. Daar is kwalitatiewe seisoenale verskille tussen die femorale klierafskeidings van individue van C. giganteus gevind.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/49754
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