Thermal ecology and embryonic development in black caiman’s (Melanosuchus niger, Spix 1758)

Do Val, HGP ORCID: 0000-0002-6919-3192, Passos, LF ORCID: 0000-0003-4529-9950, Medeiros de Barros, J, Webb, G and Coutinho, ME (2025) Thermal ecology and embryonic development in black caiman’s (Melanosuchus niger, Spix 1758). Journal of Thermal Biology, 135. p. 104357. ISSN 0306-4565

Preview

Text Thermal ecology and embryonic development in black caimans Melanosuchus niger Spix 1758.pdf - Accepted Version Available under License Creative Commons Attribution. Download (793kB) | Preview

Abstract

The black caiman (Melanosuchus niger, Spix, 1825) is a crocodilian species endemic to the Amazon biome, that nests within a defined nesting season bridging the local dry and wet seasons. Eggs are deposited in a mound of fresh and old vegetation, but little is known about the thermal relations of M. niger nests and their influence on embryo development rates and total incubation time. We present data for 7 wild nests from the southwestern Brazilian Amazon, gathered in 2019 and 2024. The mean incubation period from laying to hatching was 77.1 ± 8.3 days (SD; range 71.3–93.8 days). Nest temperatures were subject to daily cycling and baseline shifts over time, and had an overall mean of 31.6 ± 1.65 °C (range 27.2 °C–35.9 °C). The nests insulate and buffer the eggs against ambient temperature extremes. Mean nest temperature increases with nest size, and precipitation causes baseline declines in temperature. High nest temperatures (33.6 ± 1.39 °C) in one nest disrupted normal embryo development, and may have affected another. Embryo development rates within 6 nests, and their interactions with nest temperatures, survival to hatching and development time between laying and hatching are investigated. Based on nest temperatures we consider it likely that the M. niger nests we studied would have produced hatchlings with a female bias but could not confirm it.

Item Type:	Article
Uncontrolled Keywords:	3109 Zoology; 3103 Ecology; 31 Biological Sciences; 06 Biological Sciences; Physiology; 3109 Zoology
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences Q Science > QH Natural history > QH301 Biology
Divisions:	Biological and Environmental Sciences (from Sep 19)
Publisher:	Elsevier BV
Date of acceptance:	11 December 2025
Date of first compliant Open Access:	23 December 2025
Date Deposited:	23 Dec 2025 11:41
Last Modified:	23 Dec 2025 11:41
DOI or ID number:	10.1016/j.jtherbio.2025.104357
URI:	https://researchonline.ljmu.ac.uk/id/eprint/27775

View Item