Abstract
Caecilian amphibians are burrowing predators of tropical soil ecosystems. They have exceptionally diverse reproductive modes (e.g. oviparity, viviparity). The project is an integrative analysis of the evolution of this reproductive diversity. We hypothesise a linear sequence of evolutionary changes between reproductive modes, the extent and form of investment in propagule size and quality, and regimes of parental care. We will test the hypothesised evolutionary changes by integrating data on different modes in a comparative phylogenetic context. We also aim to test the 'skin feeding' hypothesis for the function of the enigmatic 'foetal' teeth' recently discovered in oviparous caecilians. A broad range of classical and modern methods will be used in an innovative combination of detailed laboratory and field study designed to directly test explicit hypotheses. Morphological data on foetal teeth will be generated with SEM (Scanning Electron Microscopy), histology and cleared and stained specimens. At field sites in Tanzania and French Guyana direct observations of parental-offspring interactions will be made. Morphometric data will be recorded in the field and also from preserved material. Molecular systematics will be applied to place new species studied in this research intophylogenetic context and further to check the association of different life history stages. Multivariate statistical analysis is used to test the predicted correlations of maternal traits. The main outcome will be an understanding of the pattern of evolution of reproductive modes with implications for the use of caecilians as a model system for studying the evolution of tetrapodterrestriality and the origin of amniotes. Additional major outcomes include, provision of baseline data on the life histories and reproductive ecology of a range of previously unstudied species that will be useful in the context of conservation management and monitoring. Given #
Europe