Thermoregulation in captive broad-snouted caiman (Caiman latirostris)

Abstract

Background: Crocodilians 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. Results: The 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. Conclusions:The 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.

Effects of change in temperature on the cardiac contractility of broad‐snouted caiman (Caiman latirostris) during digestion

“…C. latirostris is an opportunistic predator that inhabits wetlands in tropical and subtropical South America (Scott et al, 1990). Bassetti et al (2014) studied the thermoregulation in captive broad‐snouted caiman under resting conditions and verified that the maximum body temperature reaches 31°C between 2:00 p.m. and 7:00 p.m. at rest conditions. There have been relatively few reports on mechanisms underlying the SDA in crocodilians.…”

Thermal history and gape of individual Mytilus californianus correlate with oxidative damage and thermoprotective osmolytes

“…'Heated' and '4 h post-heating' group mussels were emersed and exposed to heat stress using an electric coil heater and a Micro-Infinity temperature controller (Newport Electronics, Santa Ana, CA, USA). Temperature was ramped at +7°C h −1 from 15°C to 36°C to simulate solar heating on a hot day during low tide (Tomanek and Somero, 1999;Lockwood et al, 2010;Denny et al, 2011). The mussels were held at 36°C for one additional hour before the heated group was dissected.…”

“…Alternatively, the correlation of taurine content and individual thermal history could relate to taurine's role as a prominent osmoregulatory agent (Lange, 1963). Heat stress has been documented to impair osmoregulatory ability (Tang et al, 2014), and the maintenance of active osmoregulation has been hypothesized to contribute to thermal tolerance (Jian and Huang, 2001;Xu et al, 2013). Further mechanistic work is required to document the relative importance of these various putative benefits of taurine accumulation under episodic exposure to thermal stress.…”

Corticosterone levels and immunological indices in stressed juvenile broad‐snouted caimans

“…In A. mississipiensis and C. acutus, the optimum temperature range for feeding is considered to be between 25 and 35°C (Lang, 1979;Turton et al, 1997). The optimum temperature range for C. latirostris is between 23°C and 35°C (Basetti et al, 2014), but the results reported suggest that caimans perform better at higher temperatures. Other authors reported enhanced growth in C. latirostris at high temperatures.…”