Comparative analysis of the development of the lizard, Liolaemus tenuis tenuis. II. A series of normal postlaying stages in embryonic development

Abstract

In this work, we have completed a study of the development of the ovoviviparous lizard Liolaemus tenuis tenuis. Ovoviviparity in this lizard is a condition in which eggs are retained within the reproductive duct for about 60 days. During this period the phases of segmentation, gastrulation, neurulation, presomitic, and somitic embryos transpire. During the months of December and January the eggs are laid, and at this time the embryos are comparable to stage 27 Liolaemus gravenhorsti lizard embryos, or to stage 29 Calotes versicolor lizard embryos. Differentiation of the facial region occurs between Days 12 and 42 after egg laying. Limbs develop rapidly between the 8th and 23rd days. By 53 days the appendicular skeleton is completely formed. After 36 days the mesonephros begins to degenerate, and its function is gradually taken over by the developing metanephros. Newborn lizards do not possess an egg caruncle. During the period up to hatching, there is a great increase of liquid within the egg, presumably amniotic fluid. Cracks develop in the leathery shell shortly before hatching and are, perhaps, the first sign of the onset of hatching. Increase of liquid in the egg during postlaying development accounts for its increase in weight and change in shape. Weight of the embryo at hatching does not exceed 32% of the total weight of the egg.

Observations on the embryology of the unisexual lizard Cnemidophorus uniparens (Teiidae)

“…While 17 lizard familes are recognized (Estes, 1983), comprehensive descriptions of embryogenesis exist for only three species in two families (Lacertidae: Dufaure & Hubert, 1961;Iguanidae: Lemus, 1967;Lemus, Illanes, Fuenzalida, Paz de la Vega & Garcia, 1981). Of these three studies, two describe development in viviparous species: Lacerta viuipara (Dufaure & Hubert,196 1) and Liolaemus gravenhorstii (Lemus, 1967;Lemus et al, 1981); and one describes development in an oviparous species, Lacerta agilis (Peter, 1904). Unfortunately, the staging table for L. agilis is rarely cited in discussions of oviparous lizard development.…”

Contributions to the study of oviparity–viviparity transition: Placentary structures of Liolaemus elongatus (Squamata: Liolaemidae)

“…To ascribe embryonic development to the developmental stages described by Lemus and Duvauchelle (1966) and Lemus et al (1981) for Liolaemus tenuis tenuis, we considered somite number, limb development, and the following distances: 1) apex-mesencephalon to frontal process, 2) apex-mesencephalon to posterior trunk flexure, and 3) apex-diencephalon to apexcervical or nuchal flexure ( Fig. 1A).…”

“…The genus Liolaemus could be considered a model to study the structural and functional diversity of placentas and the transition from oviparity to viviparity. Liolaemus includes almost equal numbers of oviparous and viviparous species (Donoso Barros, 1966;Cei, 1986Cei, , 1993Schulte et al, 2000) and presents significant advantages for experimental work: gravid females survive multiple surgeries, their eggs successfully develop in terraria, and the embryos can be cultured and experimentally manipulated (Lemus and Duvauchelle, 1966;Lemus, 1967;Lemus and Badínez, 1967;Lemus and Wacyk, 1969;Leyton et al, 1980;Lemus et al, 1981). From a biogeographic point of view, Liolaemus species inhabit biotopes of several kinds, in which the individuals undergo climatic constraints via short activity seasons and long hibernation periods Cussac, 1998, 1999).…”

Development of olfactory epithelium and associated structures in the green iguana,Iguana iguana—light and scanning electron microscopic study

“…Valuable morphologic criteria for developmental staging are the development of limbs and pharyngeal arches (Wise, Vickaryous & Russel, 2009). General embryonic development has been described in several reptilian species such as the Calotes versicolor (Muthukkaruppan et al, 1970), the Uta stansburiana (Andrews & Greene, 2011) and the Liolaemus tenuis tenuis (Lemus et al, 1981). …”