Embryological development of Salvator merianae (Squamata: Teiidae).

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.

Embryological development of Caiman latirostris (Crocodylia: Alligatoridae).

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.