GULAR AND PARACLOACAL GLAND SECRETIONS OF CROCODILIANS - A COMPARATIVE-ANALYSIS BY THIN-LAYER CHROMATOGRAPHY

The gular and the paracloacal gland secretions of 21 crocodilian species, including representatives of all extant genera-Alligator, Caiman, Crocodylus, Gavialis, Melanosuchus, Osteolaemus, Paleosuchus, and Tomistoma-were analysed by thin-layer chromatography. Secretions from one adult male and one adult female were examined separately for most species. Gular and paracloacal gland chromatograms display bands consistent with sterols, free fatty acids, triglycerides, steryl esters, and other compound classes. Comparisons of gular and paracloacal chromatograms of each species suggest qualitative and/or quantitative differences in the compounds produced in each gland type. Our results provide tentative evidence for taxonomic variation in crocodilian skin gland secretions. Comparisons of gular and paracloacal gland chemicals of extant species allow inferences to be made on the chemicals produced by these organs in ancestral crocodilians.