Maternal investment in the viviparous caecilian amphibian Typhlonectes natans (Gymnophiona: Typhlonectidae)

Abstract Modern amphibians have an extraordinary diversity of reproductive modes including varieties of oviparity and viviparity. Oviparous and viviparous caecilian amphibians show high degrees of parental investment including dermato- and uterotrophy. We examined maternal investment and reproductive biology correlations of the aquatic viviparous caecilian amphibian Typhlonectes natans. Litter sizes ranged from two to ten pups, whereas litter masses averaged around 28% of maternal mass and pups reached up to 43% of the female total length. Maternal size was positively related to litter size and to the average pup body size. Although overall fecundity is reduced in viviparous teresomatan caecilian amphibians, as clutch size is decreased in comparison to oviparous ichthyophiid caecilians, a lower fecundity of viviparous taxa is compensated via uterotrophy leading to an increased offspring size and quality.