Artificial manipulation of incubation temperature has been proposed as a potential strategy for mitigating the effects of climate change on sea turtles for which sex determination is temperature-dependent, but thermal manipulation may also affect hatchling survival. Here, we demonstrated that incubation and water temperatures influenced several performance traits that contribute to the survival of loggerhead sea turtles (Caretta caretta) during the post-hatchling dispersal phase. Hatchlings from warm incubation temperatures (31 °C) had significantly shorter incubation periods, higher initial swimming performance, lower sustained swimming performance, and lower growth rates during the first three weeks post-hatching, as well as higher blood glucose concentrations, than those from cool incubation temperatures (27.5 °C). Hatchlings in warm water temperatures (30 °C) exhibited significantly greater swimming performance than those in cool water temperatures (27 °C). Our results indicated that altering incubation temperatures indirectly influences the survival of loggerhead hatchlings by modifying their swimming performance and growth rates, which may affect hatchling predator-avoidance capability. Moreover, thermal manipulation may alter the incubation period, exposing hatchling to water temperatures that they would not otherwise normally experience, which may affect swimming performance. Our results suggest that such conservation strategies may influence their survival, and thus should be carefully considered.
The widespread use of tris(1,3‐dichloro‐2‐propyl) phosphate (TDCIPP) as a flame retardant has led to its release to the environment. Thus, the toxicological effects of TDCIPP on humans and animals are of importance. For better understanding of its potential toxicities, TDCIPP (250, 500, or 650 mg/kg/day) or vehicle control was administrated orally to adult male Wistar‐Imamichi rats for 7 days. After the final administration of compounds, organ weights, histopathology, blood biochemistry, and hematology were examined. Hepatic toxicity was observed at doses ≥ 500 mg/kg/day of TDCIPP, and renal toxicity was observed at 650 mg/kg/day. The anti‐androgenic activity of TDCIPP was previously confirmed in vitro and in vivo, but weights of epididymis, an androgen‐dependent organ, were not affected by TDCIPP treatment in adults. Serum alkaline phosphatase activity was significantly decreased in all TDCIPP‐treated rats independent of dose. Hemoglobin concentration, hematocrit, red blood cell count, and reticulocyte count were decreased in all TDCIPP‐treated rats, but mean corpuscular volume, total iron‐binding capacity, and serum iron were normal, suggesting that renal anemia was caused by TDCIPP. Together with previous reports on effects of anti‐androgenic substances on red blood cell indices, anemia caused by TDCIPP could be due to its anti‐androgenic activity. These considerations will contribute to further assessment of the toxicity of the compound.
Although scute pattern abnormalities in sea turtle species are considered to be strongly correlated with survival rate, there is little information available regarding these abnormalities and the primary cause for their development is unclear. For the conservation of sea turtle species, accumulating basic knowledge of scute pattern abnormalities is a fundamental step towards a better understanding of the causes of these abnormalities. In the present study, we counted vertebral and costal scutes from adults hunted for food (male and female) (n = 899), nesting females (n = 155), and hatchlings (n = 44,537) of the green sea turtle (Chelonia mydas) from the Ogasawara Archipelago, Japan. We found that the frequency of turtles with non-modal scute patterns was significantly greater in adult females than that in adult males (P = 0.02). Since females are produced by warmer incubation temperatures, and the period of sex determination coincides with the period of scute pattern determination, high incubation temperatures may be responsible for the induction of scute pattern abnormalities. Moreover, females with non-modal scute patterns produced a higher frequency of hatchlings with non-modal scute patterns than females with modal scute patterns (P < 0.01), indicating that scute abnormality may be heritable. For conservation of this species, our results suggest that decrease of the incubation temperature by cooling methods, such as provision of shade, may minimize the frequency of non-modal scute patterns, with consideration for the natural sex ratio.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.