Meeting Abstract
3.4 Sunday, Jan. 4 Reproductive and developmental biology of caecilian amphibians KUPFER, A; KUEHNEL, S; VETTER, J; OLSSON, L*; Friedrich-Schiller-Universit Jena Lennart.Olsson@uni-jena.de
Amphibians are of prime interest for evolutionary reproductive biology because offspring nourishment encompasses a continuum from lecithotrophy to matrotrophy combined with oviparity and viviparity. Caecilians are limbless tropical amphibians, which display a high diversity of reproductive modes. In contrast to most amphibians caecilians mostly favour terrestrial reproduction, which includes oviparity with either indirect developing aquatic larvae or direct development, and viviparity. Among amphibians caecilians also show an exceptionally high level of parental care and investment ranging from egg guarding to intra-oviductal feeding and the recently discovered maternal dermatotrophy, a.k.a. "skin feeding". Relatively little is known about caecilian reproduction and development. All caecilians have internal fertilization and the male phallodeum operates as an intromittent organ during copulation. We are investigating the anatomy of the caecilian cloaca using histology and 3D reconstruction, in particular the functional association between the specific male and female morphology and their reproductive mode. We analyzed the genital morphology of male and female Ichthyophis cf. kohtaoensis, and present the first 3D reconstructions and visualizations of genital systems of caecilians. To study comparative aspects of caecilian cloacal development, we have set up a breeding colony of the viviparous Geotrypetes seraphini in the lab in order to obtain embryos and young. Colonies of other species such as direct-developing Boulengerula ssp. are planned. Developmental studies will include study of early cloacal development and an investigation of early head development. Comparisons with our earlier studies of cranial neural crest migration and cranial muscle morphogenesis will facilite an understanding of the evolution of caecilian head morphogenesis.
