Embryological development of Caiman latirostris (Crocodylia: Alligatoridae)

Abstract

A standard development embryological series is the primary basis to organize information of any embryological study and is also used to determine the age of eggs and embryos in field conditions. In this article, we calibrate developmental series of the broad-snouted caiman, Caiman latirostris, against an established series for Alligator mississippiensis. Morphometric measures and extend of the opaque-shell banding were also related to embryo age. In earlier stages, external morphological features alone can account for embryo age, but we suggest that morphometric measurements should be introduced later in the development. Unlike morphologic and morphometric attributes, the opaque patch was not a useful age predictor. As expected, a close correlation between embryonic development of C. latirostris and A. mississippiensis was observed.

Heterochrony in limb evolution: developmental mechanisms and natural selection

“…The situation in the Caiman appears to be reversed, so that the forelimbs are initiated first, but the hind limbs then outstrip them in their subsequent development (Iungman et al, 2008). These examples suggest that heterochrony present in early stages may be silent with respect to adult morphology; in a sense, its effects are transient and can be overwritten by compensatory changes at later stages.…”

Histomorphological changes in testes of broad‐snouted caimans (Caiman latirostris) associated with in ovo exposure to endocrine‐disrupting chemicals

“…The caimans included in this study were hatched from eggs collected shortly after oviposition (i.e., embryos at stages lower than stage 15 (Iungman et al, )) from regions of low anthropogenic intervention, and were raised in controlled conditions. Thus, the contribution of the wild environment to the potential contamination of these caimans was both via maternal transfer and via the very early nest environment.…”

“…Only the nests with embryos at stages lower than 15 were transported to the laboratory. To establish developmental stages of C. latirostris embryos, we followed defined criteria (Stoker, ; Iungman et al, ). Prior to removal from the nest, the upper surfaces of the eggs were marked with a graphite pencil to keep the original egg orientation during transportation to the laboratory and incubation in controlled laboratory conditions.…”

Embryological development of Salvator merianae (Squamata: Teiidae)

“…Included among these influencing factors are temperature (Piña et al, ), humidity (Packard & Packard, ), and oxygen level (Iungman & Piña, ). Therefore, the clutch age can be evaluated from a description of the development stages of the embryos in relation to a known chronological age (Iungman, Piña, & Siroski, ; Platt, Rainwater, & McMurry, ). A determination of embryo age would allow oviposition time estimation and hatching time prediction in the context of a known incubation temperature.…”