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Throughout metamorphic development until adulthood, amphibians have important integumentary adaptations that maintain their physiological needs and protection against predation. The evolution of these strategies in the subfamily Leiuperinae has been elucidated in recent years. In this sense, the knowledge about Physalaemus ephippifer's skin features can corroborate the ontogenetic changes of these characteristics in the clade. The aims of this work were to study the ontogeny of the skin of P. ephippifer from tadpole to adult. We collected foam nests in temporary ponds as well as adult individuals in a forest fragment. In the laboratory, the animals were classified by stage development, euthanized, and fixed. Sections of the dorsolateral, lumbar, and femoral portions were dissected from the adult individuals. Samples were submitted to histological processing for light microscopy and scanning electron microscopy. In premetamorphosis phase, granular glands development is absent and secretory cells are present. In prometamorphosis, the development of the first glandular rudiments without secretion production begins, also xanthophores. During metamorphosis, mucous glands differentiated before granular glands. Until late metamorphosis ciliated cells persist and epidermis changes to an adultlike. In adults, granular glands show polymorphism with different distributions in the body, despite not having macroglandular structures. In addition, P. ephippifer individuals have few epidermal projections and cryptic coloration. Our results show that despite sharing a few morphological structures with other specimens of the Leiuperinae subfamily, the characteristics present in individuals of P. ephippifer are appropriate to the niche occupied and consistent with the changes that occur throughout their lineage. [ABSTRACT FROM AUTHOR]

Introduction: Morphometrics analysis is an efficient and low-cost technique used in studies of sexual dimorphism in turtles. Kinosternon scorpioides scorpioides, scorpion mud turtle, has a wide phenotypic variation, depending on the area of its occurrence. Objective: The objective of this work was to identify the anatomical sexual difference of K. s. scorpioides, adults and hatchlings, through morphometric analysis; and relate the weights of adult animals to environmental factors (temperature and rainfall) in Marajó Island, Brazil. Methods: The sample collection was carried out from March to September 2018, covering both the rainy season (January to July) and the dry season (August to December). For the biometric analysis, 95 adults and 21 hatchlings were used, in which the length and width of the carapace and plastron, height of the shell, and weight were measured (adults only). For the geometric morphometry analysis, 21 adults and 13 hatchlings were used, in which 27 coordinates of anatomical landmarks were inserted in each image of the carapace and 11 in the plastron. Hatchlings were sexed by histology which was enabled by the identification of the ovaries and testicles. Results: The results showed the existence of dimorphism in adults. The plastron and height were higher in females, which had a more rounded carapace than males. This characteristic may be related to the species' sexual strategy, where males impose copulation. Histologically, it was possible to identify the ovaries and testicles in the hatchlings, but there was no anatomical sexual difference, despite the tendency to differentiate in the analysis of carapace PCA. Conclusions: Sexual dimorphism in K. s. scorpioides may play an important role on its reproductive behavior, which is synchronized with environmental events. This fact suggests that the reproductive strategies of this species would be severely affected by changes in the ecosystem. [ABSTRACT FROM AUTHOR]