Embryonic and larval development of Atelopus cruciger (Lichtenstein and Martens, 1856) (Anura: Bufonidae)

Harlequin toads ( Atelopus ) are one of the amphibian groups in greatest need of urgent conservation measures, Atelopus cruciger is one of the few species with known stable populations, yet basic natural history, including the embryonic and larval stages, remains largely unknown. We describe for the first time the development of its tadpole, from egg to tail resorption. The tadpole of Atelopus cruciger is gastromyzophorous with a general morphology resembling that for other congeneric species but with a distinct W-shaped whitish band that spans transversely across the midline of its dorsum. Development from egg to tail resorption takes between 110—147 days. In the wild, tadpoles live camouflaged beneath and alongside rocks in shallow sections of fast-flowing streams, with clear soft waters.