Thermoregulation in captive broad-snouted caiman (Caiman latirostris)

Thiago S Marques,Adriana Malvásio,Carlos I Piña,Luís Ab Bassetti,Luciano M Verdade

doi:10.1186/1810-522x-53-9

Abstract

BackgroundCrocodilians are ectothermic animals. For this reason, the environmental temperature has substantial effects on their physiology and behavior. The thermoregulatory behavior of these animals involves the selective use of different types of environments. This behavior enables them to reach the temperature level for their metabolic activities. This study aimed to determine the influence of sex, body size, and reproductive stage on the body temperature (T b) of adult broad-snouted caiman (Caiman latirostris) in captivity. Thermal sensors were surgically implanted in the peritoneal cavity of 16 adult females and 4 adult males and programmed to register T b hourly during 6 months.ResultsThe diel T b pattern of the broad-snouted caiman reflected the variation among the microenvironmental temperatures used by the species (water surface, pool bottom, and ground). The sex of the animals had influence on their T b, but body size did not. Reproductive females had higher T b than non-reproductive females during October to early November. It is possible that this difference is a result of the ovulation period of the species. Sick animals appeared to show behavioral fever.ConclusionsThe results of the present study suggest that several factors can affect the T b of adult broad-snouted caiman in captivity. Future studies should focus on the possible effect of thermoregulatory behavior on individuals' growth rate and reproductive performance.

Highlights

The presence of osteoderms in the crocodilians facilitates this process because small holes filled with arterioles can absorb heat and carry it to other parts of the body (Seidel 1979)
The animals showed a clear diel variation in Tb during the study period (August 2000 through January 2001), with a minimum temperature of 17°C to 23°C in the morning (0900 to 1000 hours) and a maximum temperature of % 32°C to 35°C in the afternoon (1400 to 1700 hours). This pattern coincides with temperature variation among the different microhabitats of the animals' facilities selectively used by the animals during the day (Figure 1)
Crocodilians are intensively managed for sustainable use of their meat and leather

Summary

Introduction

For this reason, the environmental temperature has substantial effects on their physiology and behavior. The thermoregulatory behavior of these animals involves the selective use of different types of environments This behavior enables them to reach the temperature level for their metabolic activities. For this reason, environmental temperature has substantial effects on their physiology and behavior (Pough et al 2003). The thermoregulatory behavior of these animals involves different uses of the available environments (Asa et al 1998; Fincatti and Verdade 2002; Fish and Cosgrove 1987; Seebacher et al 1999; Verdade et al 2006) This behavior enables them to reach a Tb for their metabolic activities (Seebacher and Franklin 2005; Smith et al 1978). The presence of osteoderms (dense bony plates derived from the skin) in the crocodilians facilitates this process because small holes filled with arterioles can absorb heat and carry it to other parts of the body (Seidel 1979)

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