Age structure in the false tomato frog Dyscophus guineti from eastern Madagascar compared to the closely related D. antongilii (Anura, Microhylidae)

Abstract

The false tomato frog, Dyscophus guineti, is an endemic species of eastern Madagascar, typically found in open and swampy areas of mid-elevation forests. We measured 62 females and 70 males from a population from Marovato, next to Brickaville. Snout-vent length of the individuals ranged from 37.7–112.4 mm in females and 37.7–90.7 mm in males, while the mass varied within the range 25.0–80.2 g in males and 25.8–145.6 g in females. Skeletochronological analysis was conducted on clipped phalanges of 20 males and 20 females. The results of these analyses indicated that the age range was 3–7 years in females and 3–6 years in males, and that sexual maturity was attained between 2 and 4 years, comparatively earlier in males than in females. There was a significant correlation between age and size in females. This species appears larger in size but less long-lived than the sister-species D. antongilii.

Keywords:

• Age structure
• bone growth marks
• Dyscophus
• life history
• conservation
• tropical anurans

Acknowledgements

Thanks to the Malagasy authorities for providing collecting and export permits. A.I. Carpenter kindly corrected a first draft of this paper. The study was funded by Zoo Zürich, WAZA, BIOPAT, and EAZA. D. Schuurman, K. Freeman and J. Bielby corrected and commented an early draft of the paper.