Embryonic development of the lemon-yellow tree frog, $Hyla~ savignyi$ Audouin, 1827

Abstract

Amphibians are widely used in temperature adaptation studies due to their compatibility in laboratory experiments. We investigated the embryonic development stages (from fertilization to $25^{th}$) of $Hyla ~savignyi$ following Gosner’s generalized table. Three pairs of $H.~ savignyi$ were collected during the breeding season (February 2015) from Northern Cyprus, Kalkanlı Region and maintained at 21±1 °C in the laboratory. The samples were set in 3 groups and examinations of embryos and photographs taken every 10 minutes were carried out during the 9-days embryonic period. Embryos hatched at stage 20 or 21 come up to 3rd – 4th days after fertilization. Embryonic development of $H.~ savignyi$ is about 157 hours (7 days). Cleavage is unequal holoblastic. The embryonic developmental stages of $H.~ savignyi$ were compared with the result of a similar study of two other $Hyla$ species ($H.~orientalis$ and $H.~ annectans$) at various temperatures, and the possible temporal effect of the temperature and ovum size on the growth rate of these species was discussed.