Role of photoperiod, temperature and food on development of Polypedates teraiensis (Dubois, 1987) tadpoles

Abstract

Aim: To determine the effect of environmental factors on the growth and development of Polypedates teraiensis (Dubois, 1987) tadpoles. Methodology: The study was conducted in two phases. In the first study effect of light on tadpole growth and development was conducted. Experiment No. 1 examined the effects of natural light (NDL), continuous light (LL), and constant dark (DD). Experiment No. 2 investigated the role of day length by exposing three groupsof tadpoles to either a short photoperiod (8L:16D) or a long photoperiod (13L:11D and 16L:8D). Experiment No. 3 examined the effects of light quality on tadpoles by exposing them to either short wave length (450 nm; blue light), long wavelength (650 nm; red light), or white light at equal intensity (0.45 W m2) under an equinox photoperiod (12L:12D). In the second study, the effects of food quantity and quality, as well as temperature (30±2oC vs. 20±2oC) was calculated on tadpole growth and development. Results: DD photoperiod produced the fastest growth,but long photoperiods (13L:11D and 16L:8D) delayed the growth when compared to short photoperiods (8L:16D). Furthermore, although long wavelength (650 nm; red light) delayed growth, short wave length (450 nm; blue light) speed it up. Food restriction delayed the growth and development, with 4hr group growing at a slower rate than the 12hr group. A protein-rich food combined with high temperature (30±2oC) accelerated growth. Taken together, these findings suggest that interactions among environmental factors may affect anuran development and metamorphosis. Interpretation: These findings can potentially improve amphibians' captive breeding programs and aid tools for amphibian conservation.