Reproductive ecology of female caecilian amphibians (genus Ichthyophis): a baseline study

Abstract

The remarkable diversity of reproductive modes, including levels of parental care that are extensive relative to those of the other major amphibian groups, makes the limbless tropical caecilians ideally suited for evolutionary reproductive studies. Here we present key life history data for the oviparous caecilian Ichthyophis cf. kohtaoensis. We used non-invasive methods to analyse reproductive traits, seasonality of breeding and characteristics of oviposition sites in the field (Mekong valley, north-eastern Thailand). A correlation was established between reproductive activity and season, indicated by the age of egg clutches found in the field. Eggs at early developmental stages were found at the beginning of the rainy season, those with well-developed embryos at the peak of the monsoon. The body condition of females guarding younger clutches was superior to that of females with older clutches, indicative of a loss of energy reserves during the period of parental care. Maternal total length correlated positively with the number of eggs as well as with the total length of newly hatched larvae. The terrestrial oviposition sites of females were located close to temporary and permanent ponds, small brooks and rivers. It is hoped that the study will, in addition to contributing to our understanding of the evolution of caecilian reproduction, provide a basis for further comparisons of reproductive strategies among amphibians and other terrestrial tetrapods.

Life history of an African caecilian:Boulengerula taitanusLoveridge 1935 (Amphibia Gymnophiona Caeciilidae)

“…For example, reproduction appears to be dependent on the rainy season, with eggs being laid and brooded in underground chambers, as reported for ichthyophids (KUPFER et al 2004b). Many authors have speculated that reproductive cycles of caecilians are tied to rainy seasons (e.g.…”

Identification and characterization of visual pigments in caecilians (Amphibia: Gymnophiona), an order of limbless vertebrates with rudimentary eyes

“…Burger et al, 2007). Caecilians (at least those species that are partially surface active) are mostly considered nocturnal Kupfer et al, 2004;Burger et al, 2007), so it is likely that the peak absorbance of caecilian rod photoreceptor pigments are spectrally tuned to maximize the absorbance of light and the wavelengths available in either a forest floor, soil or night environment. Tropical forests are heterogeneous in the spectral composition of ambient light (Endler, 1993), where the light varies from white in large gaps between vegetation to yellowish-red in small gaps.…”

Morphological Diversity and Evolution of Egg and Clutch Structure in Amphibians

“…kohtaoensis, Kupfer et al, 2004;Idiocranium russeli, Sanderson, 1937;Siphonops annulatus, Cei, 1980;Gö ldi, 1899;S. paulensis, Gans, 1961;Montero et al, 2005;and Typhlonectes compressicaudus, Sammouri et al, 1990).…”