Figure 3 in Prolonged parental behaviour by males of Limnonectes palavanensis (Boulenger 1894), a frog with possible sex-role reversal

Figure 3. Embryonic development of the eggs of L. palavanensis. (a) The vegetal pole differentiates from the animal pole 24 h after fertilisation. (b) Neural folds develop, Gosner stage 15 (3 days old). (c) The head forms and the tail elongates around the yolk sac, Gosner stages 18–19 (4 days old). (d) Eyes become apparent and external gills are visible, Gosner stages 21–22 (6 days old). (e) The tadpoles are now sensitive to light, the eyes are completely formed and the gills are not visible anymore, Gosner stages 24–25 (9 days old). (f) The tadpoles are ready to hatch (10 days old).