Venous blood gas in free-living eastern box turtles (Terrapene carolina carolina) and effects of physiologic, demographic and environmental factors

Abstract

Blood gas analysis serves as a useful adjunctive test for health assessment in wildlife, but is infrequently utilized in free-living reptiles. This study demonstrates that box turtle blood gas analytes depend on several physiologic and environmental parameters including season, temperature, packed cell volume and activity level.

Mechanisms of Movement Patterns: Physiology and Sex Influence Gopher Tortoise ( Gopherus polyphemus ) Movement

“…Additionally, of the 25 tortoises with initial and final lactate concentrations measured, five had lactate levels decrease during exercise. This result could be due to a shift to aerobic metabolism promoting greater efficiency during exercise compared to resting, because turtles respire in part by moving their limbs, and corresponds with other studies that found higher lactate levels turtles with low activity behavior compared to more active behavior (Adamovicz et al 2018;Klein et al 2021).…”

Mechanisms of Movement Patterns: Physiology and Sex Influence Gopher Tortoise ( Gopherus polyphemus ) Movement

“…Additionally, of the 25 tortoises with initial and final lactate concentrations measured, five had lactate levels decrease during exercise. This result could be due to a shift to aerobic metabolism promoting greater efficiency during exercise compared to resting, because turtles respire in part by moving their limbs, and corresponds with other studies that found higher lactate levels turtles with low activity behavior compared to more active behavior (Adamovicz et al 2018;Klein et al 2021).…”

Exploratory values for venous blood gas analysis of clinically healthy Hermann’s tortoises (Testudo hermanni)

“…Among the other analytes, cNa + , cHCO₃ − , and cLac were found to be similar to only one of the ranges to which they were compared: cNa + was similar to one of the values reported for Chelonia mydas ( 11 ), and cHCO₃ − was similar to the values reported in another study for Chelonia mydas ( 12 ), whereas cLac was similar to and had a narrower range than that reported for Terrapene carolina ( 6 ). Differences in cLac values likely reflect the distinct environmental pressures on each chelonian group.…”

“…The PCO₂ values were similar and had a narrower range than those presented for Chelonoidis carbonarius and Terrapene carolina ( 6 , 10 ) but different from those obtained for other chelonians. The fact that values obtained from tortoises and not turtles were closest could be due to the different physiological adaptations to diving and submersion; although terrestrial chelonians are more reliant on anaerobic metabolism than mammals are, marine chelonians, owing to their natural environment, could have developed blood buffers with different efficacies and could be more reliant upon non-respiratory buffers, as those are not dependent upon emersion.…”

“…Thirteen analytes, namely pH, pO₂, pCO₂, sO₂, cK + , cNa + , cCa ++ , cCl − , cGlu, cBase, cHCO₃ − , ctCO₂, and cLac, were compared to values reported for the green turtle ( Chelonia mydas ) ( 11 , 12 ), Negev tortoise ( Testudo werneri ) ( 7 ), Kemp Ridley’s turtle ( Lepidochelys kempii ) ( 12 ), red-footed tortoise ( Chelonoidis carbonarius ) ( 10 ), and common box turtle ( Terrapene carolina ) ( 6 ).…”

Evaluating population persistence of ornate box turtles ( Terrapene ornata ) at the northeast edge of their distribution

“…The Nachusa Grasslands population was projected as declining faster, owing largely to lower annual adult female survival (0.897 at Nachusa versus 0.974 at Ayers). Notably, shell damage from predators was previously identified as the greatest factor driving changes in the health status of ornate box turtles at Nachusa Grasslands (Adamovicz 2019), and coyotes have been reported predating on adult ornate box turtles elsewhere (Legler 1960, Metcalf and Metcalf 1979). Considering fewer turtles at Ayers Sand Prairie show signs of predator damage, coyote or other mesopredator populations may be larger at Nachusa Grasslands, contributing to lower adult survival.…”

Mechanisms of Movement Patterns: Physiology and Sex Influence Gopher Tortoise ( Gopherus polyphemus ) Movement

“…Additionally, of the 25 tortoises with initial and final lactate concentrations measured, five had lactate levels decrease during exercise. This result could be due to a shift to aerobic metabolism promoting greater efficiency during exercise compared to resting, because turtles respire in part by moving their limbs, and corresponds with other studies that found higher lactate levels turtles with low activity behavior compared to more active behavior (Adamovicz et al 2018;Klein et al 2021).…”

Exploratory values for venous blood gas analysis of clinically healthy Hermann’s tortoises (Testudo hermanni)

“…Among the other analytes, cNa + , cHCO₃ − , and cLac were found to be similar to only one of the ranges to which they were compared: cNa + was similar to one of the values reported for Chelonia mydas ( 11 ), and cHCO₃ − was similar to the values reported in another study for Chelonia mydas ( 12 ), whereas cLac was similar to and had a narrower range than that reported for Terrapene carolina ( 6 ). Differences in cLac values likely reflect the distinct environmental pressures on each chelonian group.…”

“…The PCO₂ values were similar and had a narrower range than those presented for Chelonoidis carbonarius and Terrapene carolina ( 6 , 10 ) but different from those obtained for other chelonians. The fact that values obtained from tortoises and not turtles were closest could be due to the different physiological adaptations to diving and submersion; although terrestrial chelonians are more reliant on anaerobic metabolism than mammals are, marine chelonians, owing to their natural environment, could have developed blood buffers with different efficacies and could be more reliant upon non-respiratory buffers, as those are not dependent upon emersion.…”

“…Thirteen analytes, namely pH, pO₂, pCO₂, sO₂, cK + , cNa + , cCa ++ , cCl − , cGlu, cBase, cHCO₃ − , ctCO₂, and cLac, were compared to values reported for the green turtle ( Chelonia mydas ) ( 11 , 12 ), Negev tortoise ( Testudo werneri ) ( 7 ), Kemp Ridley’s turtle ( Lepidochelys kempii ) ( 12 ), red-footed tortoise ( Chelonoidis carbonarius ) ( 10 ), and common box turtle ( Terrapene carolina ) ( 6 ).…”

Evaluating population persistence of ornate box turtles ( Terrapene ornata ) at the northeast edge of their distribution

“…The Nachusa Grasslands population was projected as declining faster, owing largely to lower annual adult female survival (0.897 at Nachusa versus 0.974 at Ayers). Notably, shell damage from predators was previously identified as the greatest factor driving changes in the health status of ornate box turtles at Nachusa Grasslands (Adamovicz 2019), and coyotes have been reported predating on adult ornate box turtles elsewhere (Legler 1960, Metcalf and Metcalf 1979). Considering fewer turtles at Ayers Sand Prairie show signs of predator damage, coyote or other mesopredator populations may be larger at Nachusa Grasslands, contributing to lower adult survival.…”

Mechanisms of Movement Patterns: Physiology and Sex Influence Gopher Tortoise ( Gopherus polyphemus ) Movement

“…Additionally, of the 25 tortoises with initial and final lactate concentrations measured, five had lactate levels decrease during exercise. This result could be due to a shift to aerobic metabolism promoting greater efficiency during exercise compared to resting, because turtles respire in part by moving their limbs, and corresponds with other studies that found higher lactate levels turtles with low activity behavior compared to more active behavior (Adamovicz et al 2018;Klein et al 2021).…”

Exploratory values for venous blood gas analysis of clinically healthy Hermann’s tortoises (Testudo hermanni)

“…Among the other analytes, cNa + , cHCO₃ − , and cLac were found to be similar to only one of the ranges to which they were compared: cNa + was similar to one of the values reported for Chelonia mydas ( 11 ), and cHCO₃ − was similar to the values reported in another study for Chelonia mydas ( 12 ), whereas cLac was similar to and had a narrower range than that reported for Terrapene carolina ( 6 ). Differences in cLac values likely reflect the distinct environmental pressures on each chelonian group.…”

“…The PCO₂ values were similar and had a narrower range than those presented for Chelonoidis carbonarius and Terrapene carolina ( 6 , 10 ) but different from those obtained for other chelonians. The fact that values obtained from tortoises and not turtles were closest could be due to the different physiological adaptations to diving and submersion; although terrestrial chelonians are more reliant on anaerobic metabolism than mammals are, marine chelonians, owing to their natural environment, could have developed blood buffers with different efficacies and could be more reliant upon non-respiratory buffers, as those are not dependent upon emersion.…”

“…Thirteen analytes, namely pH, pO₂, pCO₂, sO₂, cK + , cNa + , cCa ++ , cCl − , cGlu, cBase, cHCO₃ − , ctCO₂, and cLac, were compared to values reported for the green turtle ( Chelonia mydas ) ( 11 , 12 ), Negev tortoise ( Testudo werneri ) ( 7 ), Kemp Ridley’s turtle ( Lepidochelys kempii ) ( 12 ), red-footed tortoise ( Chelonoidis carbonarius ) ( 10 ), and common box turtle ( Terrapene carolina ) ( 6 ).…”

Evaluating population persistence of ornate box turtles ( Terrapene ornata ) at the northeast edge of their distribution

“…The Nachusa Grasslands population was projected as declining faster, owing largely to lower annual adult female survival (0.897 at Nachusa versus 0.974 at Ayers). Notably, shell damage from predators was previously identified as the greatest factor driving changes in the health status of ornate box turtles at Nachusa Grasslands (Adamovicz 2019), and coyotes have been reported predating on adult ornate box turtles elsewhere (Legler 1960, Metcalf and Metcalf 1979). Considering fewer turtles at Ayers Sand Prairie show signs of predator damage, coyote or other mesopredator populations may be larger at Nachusa Grasslands, contributing to lower adult survival.…”