Natural History and Reproductive Data of Kurixalus yangi (Anura: Rhacophoridae) in Nagaland, India

Abstract

The genus Kurixalus Ye, Fei et Dubois, 1999 (Rhacophoridae Hoffman, 1932) is a small and taxonomically difficult group of treefrogs for which biological and reproductive data are missing for most of the species. A recent study of the K. odontotarsus species group (Yu et al., 2017a) revealed numerous undescribed lineages. Among them a lineage comprising specimens from Myanmar and western Yunnan, China was described as K. yangi. We report here the presence of a population of this species from Nagaland, North East India, identified by DNA barcoding of the 16S rRNA gene and morphology. A pair of adults found in amplexus is described morphologically. Data on reproduction and developmental mode were until now unknown for the continental species of this genus. Observation of reproduction in the field of K. yangi from Nagaland provided us data on its reproductive activity including spawning behavior and reproductive mode, and details on the larval developmental timing. The tadpole of this species is described for the first time including buccal anatomy. Adults are commonly found in the stumps of bamboo internodes. They breed in forest ponds, temporary rain pools or rain water tanks. Breeding activity starts from mid-April till late part of July. Unpigmented eggs measure 2.4 – 2.7 mm and are laid underwater. Under natural conditions (air temperature 18 – 30°C, water temperature 12 – 24°C), the frog complete its larval life cycle in 47 days. The tadpole shows a «classical» pond-dwelling morphology and reproductive mode. These reproductive data are compared to the Taiwanese species for which the developmental mode is well known and the evolution of the reproductive modes within the genus is discussed.