Early development and differentiation of the Laysan albatross (Phoebastria immutabilis(Rothschild, 1893): Procellariiformes)

Abstract

Bird incubation is subdivided into two phases: differentiation (embryonic phase) and growth (fetal phase). Most birds have a relatively short incubation period (20-30 days) with the phase transition occurring midway through the incubation period. The Laysan albatross (Phoebastris immutabilis) is a large pelagic bird with a long incubation period. The purpose of this study was to document the differentiation phase with the aim of ascertaining the impact of a lengthened incubation on embryonic development. Eighty-two previously collected albatross embryos were examined, measured, and staged. The albatross was found to develop more slowly than smaller birds, with a rate similar to other long-incubating birds. Legs and wings grow at similar rates but exhibit variation in growth among their anatomical components. While the albatross embryos shared some morphological stages with chickens, they were more similar to ducks and pelicans. Special features of the albatross not shared with the Gallianserae (chickens and ducks) included an alligator-like curved tail, narial tubes, and a cloacal bulge. Further examination of other larger pelagic birds with long incubation periods are needed to determine the uniqueness of the Laysan albatross embryonic development. Although much embryonic phase growth was documented in the postnatal period, little is known about the later, fetal phase in Laysan albatross. Future studies should involve examination of later (post day 32) fetuses. J. Morphol. 277:1231-1249, 2016. © 2016 Wiley Periodicals, Inc.

The uropygial gland of the monk parakeet Myiopsitta monachus: Histology, morphogenesis, and evolution within Psittaciformes (Aves)

“…For example, they appear at day eight in zebra finches ( Taeniopygia guttata , Passeriformes) and pigeons (Columbiformes), at day ten in chickens ( Gallus gallus , Galliformes), Japanese quail ( Coturnix coturnix , Galliformes), and Peking ducks ( Anas platyrhynchos , Anseriformes), at day 12 in budgerigars ( Melopsittacus undulatus , Psittaciformes), and at day 13 in Laysan albatross ( Phoebastria immutabilis , Procellariiformes; Bride & Gomot, ; Jacob & Ziswiler, and bibliography cited therein; Fukui, ; Fukui, ; Rehorek et al, ). However, only the characterization of the developmental stages of some of these species (i.e., Gallus gallus , Hamburger & Hamilton, ; Coturnix coturnix , Ainsworth, Stanley, & Evans, ; Phoebastria immutabilis , Rehorek, Smith, & Beeching, ) are available in the bibliography, including our species under study ( Myiopsitta monachus , Carril & Tambussi, ), and it is on these species that we base our comparisons. We rely on that embryological stages are an appropriate tool for comparison between birds because they standardize homologous morphological events which are independent of incubation time and body size, so that changes in development trajectories when comparing species could indicate heterochronies (Starck, ).…”

Ontogeny of the American alligator (Alligator mississippiensis) prenatal head: A morphometric approach

“…This leaves stages, which are artificial groupings of embryos based upon predetermined morphological features, as a viable potential metric. When staging tables are available, they are used to great effect to enable cross‐species comparisons within archosauria (Deeming & Ferguson, 1990; Rehorek et al, 2016).…”

“…Additional statistical techniques involve the calculation of various head indices (Karimi et al, 2011; Onar, 1999; Onar & Günes, 2003; Onar & Pazvant, 2001; Saber & Gummow, 2015). Not all morphometric studies involve multivariate statistical analysis, and some only summarize the data (de Almeida et al, 2015; Rehorek et al, 2016). Moreover, the data sets are often underanalysed as suitable replication, especially in ontogenetic studies, is difficult to obtain.…”

Embryogenesis of the Uropygial Glands in the Laysan Albatross (Phoebastria immutabilis (Rothschild, 1893): Procellariiformes)

“…(1) Allometry: The Laysan Albatross is the largest bird in this group of described birds (Gill, ). (2) Length of incubation period: The Laysan Albatross incubation period is the longest, at 65 days (Rehorek et al, ). (3) The absence of sufficiently detailed comparative descriptions.…”

“…We examined a total of 49 mostly intact embryos aged between days (±day) 12 and 32 post‐oviposition (see Table ). Specimens were initially fixed and stored in 10% formalin in 1968–1969, and for his study separated (according to the staging system of Rehorek et al, ), described, and measured individually. These anatomical measurements were restricted to maximum observable length and breadth of the uropygial groove.…”