@article{KupferMaxwellReinhardetal.2016,
  author    = {Kupfer, Alexander and Maxwell, Erin and Reinhard, Sandy and Kuehnel, Susanne},
  title     = {The evolution of parental investment in caecilian amphibians: a comparative approach},
  series = {Biological journal of the Linnean Society : a journal of evolution},
  volume    = {119},
  journal   = {Biological journal of the Linnean Society : a journal of evolution},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0024-4066},
  doi       = {10.1111/bij.12805},
  pages     = {4 -- 14},
  year      = {2016},
  abstract  = {Parental care is widespread among vertebrates and the observed patterns of parental care and investment are extremely diverse. Among amphibians, caecilians (Gymnophiona) exhibit considerable variation in reproductive modes, including both oviparity and viviparity, combined with highly unusual investment strategies (e.g. skin-feeding and intrauterine feeding). In the present study, current knowledge on the reproductive modes is integrated into an analysis of the evolutionary scenario of parental investment of caecilians. Phylogenetically basal caecilians possessing a biphasic life cycle that includes an aquatic larval stage invest in macrolecithal eggs directly corresponding to size at hatching. Some phylogenetically derived caecilians (i.e. the Teresomata) have a smaller clutch size and show a reduction to either medium-yolked (mesolecithal) or small-yolked (microlecithal) eggs. Via alternative pathways of parental investment, such as intrauterine feeding in viviparous taxa and maternal dermatotrophy in oviparous taxa, teresomatan caecilians increase both offspring size and quality. However, more data regarding reproductive biology are needed to obtain a fully resolved understanding of the evolution of reproduction in caecilian amphibians. (C) 2016 The Linnean Society of London},
  language  = {en}
}
@article{KuehnelKupfer2012,
  author    = {Kuehnel, Susanne and Kupfer, Alexander},
  title     = {Sperm storage in caecilian amphibians},
  doi       = {10.1186/1742-9994-9-12},
  year      = {2012},
  language  = {en}
}
@misc{KuehnelKupfer2017,
  author    = {Kuehnel, Susanne and Kupfer, Alexander},
  title     = {Sperm storage in caecilian amphibians},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-400987},
  pages     = {5},
  year      = {2017},
  abstract  = {Background: Female sperm storage has evolved independently multiple times among vertebrates to control reproduction in response to the environment. In internally fertilising amphibians, female salamanders store sperm in cloacal spermathecae, whereas among anurans sperm storage in oviducts is known only in tailed frogs. Facilitated through extensive field sampling following historical observations we tested for sperm storing structures in the female urogenital tract of fossorial, tropical caecilian amphibians. Findings: In the oviparous Ichthyophis cf. kohtaoensis, aggregated sperm were present in a distinct region of the posterior oviduct but not in the cloaca in six out of seven vitellogenic females prior to oviposition. Spermatozoa were found most abundantly between the mucosal folds. In relation to the reproductive status decreased amounts of sperm were present in gravid females compared to pre-ovulatory females. Sperm were absent in females past oviposition. Conclusions: Our findings indicate short-term oviductal sperm storage in the oviparous Ichthyophis cf. kohtaoensis. We assume that in female caecilians exhibiting high levels of parental investment sperm storage has evolved in order to optimally coordinate reproductive events and to increase fitness.},
  language  = {en}
}