Embryonic development of Columba livia(Aves: Columbiformes) from an altricial-precocial perspective

Objective: this study characterized the morphogenesis of Columba livia and proposed a table with 43 embryonic stages. The ontogeny of this species was divided into three phases: early, middle and late. Methods and Results: the early phase (stages 1-26) includes the final period of segmentation, gastrulation, neurulation and somitogenesis, organization of the extraembryonic membranes, and the initial formation of the major organic systems. The middle phase (stages 27-36) was characterized mainly by the growth of limbs and the organization of the autopodium, the formation and growth of the peak, and the development of integumentary annexes such as feather germs and leg scales. The late phase (stages 37-43) shows the overall embryo growth, the final organization of the pterilosis pattern and growth of feather germs, as well as final consumption of the yolk, and hatching. Conclusions: these results allow making comparisons with the proposed developmental events of Gallus gallus domesticus, highlighting similarities and differences in the ontogenetic sequence of both species. Therefore we propose some hypotheses about possible heterochronic events related to altricial-precocial developmental models.