Embryological development of Salvator merianae (Squamata: Teiidae)

Abstract

Summary Here we describe the embryonic development of Salvator merianae external morphologic features, as based on observation of 28 embryos across different days of incubation at 31 ± 0.5°C. Observed developmental stages were grouped and classified into the early, middle, and late periods. The early period (Stages 3–11) is distinguished by the origin of the encephalic vesicles, sensory placodes, pharyngeal arches, and degree of body flexion and rotation. The medium period (Stages 8–15) is distinguished by limb differentiation and by cranium‐facial characteristics. The late period (Stages 15–18) is determined by scale patterns, pigmentation, and embryo growth.

Ultrastructure of eggshell and embryological development ofSalvator merianae(Squamata: Teiidae)

“…According to several authors, the description of embryonic stages could have differences in terms of chronology even if they have the same controlled incubation conditions, thus presenting congruences between the comparisons (Wise et al 2009, Lima et al, 2018. Although in S. merianae, embryonic stages were recently described (Iungman et al, 2019), these consider different stages that are described in this article. Particularly to S. merianae, the embryos presented nearly the development stage after oviposition that corresponds to 13-14 Lacerta vivípara, characterized by the formation of the primitive streak (Dufaure and Hubert 1961).…”

“…This study is the first contribution to embryology and the embryonic state in which the S. merianae egg is laid. Although there is a brief description of this species (Iungman et al, 2019), it is not specified about the oviductal transit or the first stages of development since they describe the development after 72 hr of incubation (stage 5).…”

“…The characterization of each stage was done based on the external morphological characters (branchial arches, eyelids, limbs, claws, pigmentation of the body, development of scales, and egg teeth). The embryos were carefully analyzed and compared with other lizards (Lacerta vivipara jacquin [Dufaure and Hubert 1961]; Lioluemus gravenhorsti (Lemus, 1967); Lioluemus tenuis tenuis [Lemus andDuvauchelle 1966, andLemus et al, 1981]; Gallus agllus domesticus [Hamburger and Hamilton 1992]; Polychrus acutirostris [ Alvarez et al, 2005]; Caiman latirostris [Iungman et al, 2008]; Paroedura pictus [Noro et al, 2009]; genus Anolis [Sanger et al, 2008]; Eublepharis macularius [Wise et al, 2009]; Taeniopygia guttata [Murray et al, 2013]; Rhea americana [Melo de Almeida et al, 2015]; Salvator merianae [Iungman et al, 2019]) also we considered other features that were not regarded by these authors.…”

“…To compare the embryology of several vertebrates, it is required to describe the early development features. Although many species these data are not available, developmental staging tables for lizards include Lacertilia (Dufaure and Hubert 1961), Tropiduridae (Py-Daniel et al, 2017), Iguanidae (Iungman et al, 2019) and oviparous species (Blanc, 1974;Lemus et al, 1981;Muthukkaruppan et al, 1970;Sanger et al, 2008).…”

Embryonic development of a parthenogenetic vertebrate, the mourning gecko (Lepidodactylus lugubris)

“…Detailed descriptions of embryonic development facilitate effective experimental design and allow for an understanding of the timing of major developmental events. Since the first squamate embryonic staging series was generated almost 115 years ago ( Lacerta agilis ), another 34 complete squamate embryonic staging series have been published (Lima et al; reviewed in References ), thus providing ample comparative material for broad investigations into trends of squamate evolution and development.…”