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

Abstract

The life histories of amphibians are considered to be well recorded and are frequently regarded as the model complex life history for vertebrates. However, only the most basic information exists for caecilians. Boulengerula taitanus Loveridge 1935 is a direct developing terrestrial caecilian commonly found in agricultural settings of the Taita Hills, Kenya. During 12 monthly visits we collected 239 caecilians by digging into soil. Caecilians were captured on every visit, although increased searching time and low capture numbers coincided when soils were dry. The condition index (ML -3 ) defines three ontogenetic stages, for which growth can be approximately followed over the sampling period through frequency histograms. Juveniles (< 140 mm) appear to become subadults (< 240 mm) around a year after hatching, while subadults mature into adults (> 240 mm) after a further year. Adult males are significantly longer than females. Mating occurs in the soil prior to egg laying at the beginning of the short rains. Females construct a chamber before laying eggs (x = 5), and are found attending eggs during incubation and after hatching. Juveniles make up the smallest proportion of the population (maximum 24% in April and May). Information produced during this study is used to develop a tentative life-table for this species.

Care and parentage in a skin‐feeding caecilian amphibian

“…Some of our observations extend those of Malonza and Measey (2005), most notably that animals as small as 214 mm may be reproductively active. We found no correlation between numbers of eggs and young and maternal length in the oviparous B. taitanus.…”

“…Collections of B. taitanus were made in the vicinity of Wundanyi (03124.070 0 -03124.935 0 S, 38121.845 0 -38122.971 0 E) in the Taita Hills of Southern Kenya at elevations of 1,270-1,450 m. Sampling was carried out after the short rainy season between 15-22 January 2004 and 10-18 January 2005 in small agricultural holdings (for details of other fieldwork conducted here, see Malonza and Measey, 2005). Each site was searched for caecilians by digging soil up to depths of 70 cm for 20-30 min with the assistance of local farmers.…”

“…and agricultural soil ecosystems (Malonza and Measey, 2005). It is oviparous and iteroparous; eggs are laid in terrestrial nests and develop directly without an aquatic larval stage (Nussbaum and Hinkel,'94).…”

“…After dentitional metamorphosis, B. taitanus become generalist predators feeding on soil macrofauna such as termites, earthworms, and ants (Gaborieau and Measey, 2004). Although B. taitanus is the only caecilian for which an account of monthly collections over a full year has been published (Malonza and Measey, 2005), the duration of parental care, the extent of parental investment, and its energetic and other possible costs are not known.…”

A new species of Boulengerula Tornier, 1896 (Amphibia: Gymnophiona: Herpelidae) from Kenya and the “rediscovery” of Boulengerula denhardti

“…This species does not appear to be as abundant (or at least not as readily found) as some of its congeners. Some other Kenyan Boulengerula, for example B. taitanus and B. niedeni, are more readily found in farmland than in forest (Malonza & Measey, 2005;Malonza et al, 2010) but whether B. spawlsi occurs outside of forest remains to be determined. The presence of B. spawlsi in a protected areas implies some protection for the species, but the extent of its distribution in the forests of the Nyambene Hills (e.g.…”