Upper row: developmental stages in Rivulus spp. (A) Stage one: approximately 50% epiboly; (B) Stage two: neural keel. (C) Stage three: optic cups; (D) Stage four: pigmentation in eyes and skin; (E) Stage five: embryo surrounding yolk sac. Lower row: (F-I) Morphological effects of air-exposed development. (A, B, F, G) C. magdalenae. (C, H, I) C. brunneus. (D) L. frenatus. (E) C. kuelpmannii. Images are not to scale.