Blood analytes of oceanic-juvenile loggerhead sea turtles (Caretta caretta) from Azorean waters: reference intervals, size-relevant correlations and comparisons to neritic loggerheads from western Atlantic coastal waters

Abstract

This study reports reference intervals and correlations of blood analytes of oceanic-juvenile loggerhead sea turtles from Azorean waters with body size and comparison of data to neritic loggerheads from the US Atlantic coast. The observed findings highlight conservation-relevant biological (e.g. diet, somatic growth) and habitat differences among both populations.

Blood biochemistry and haematology of migrating loggerhead turtles (Caretta caretta) in the Northwest Atlantic: reference intervals and intra-population comparisons

“…The median for PCV/Hct for migratory turtles in the Mid-Atlantic was significantly higher than that of resident turtles in Core Sound; however, migratory turtles also had a greater median SCL_NT, which could affect interpretation of the observed difference. As documented in previous studies (Frair, 1977; Frair and Shah, 1982; Bolten and Bjorndal, 1992; Osborne et al , 2010; Stacy et al , 2018), there is a positive correlation between body size and blood cell characteristics, including size and quantity of cells. That said, an increase in PCV/Hct also could provide migratory loggerhead turtles with enhanced capacity for oxygen delivery to support sustained, aerobic activity during long-distance migration (Krause et al , 2016).…”

“…Migratory turtles had higher levels of ABS Azuros and ABS Lymphs, and lower levels of ABS Monos compared with turtles resident at nearshore foraging grounds. Stacy et al (2011) recommends combining ABS Azuros and ABS Monos in all reptile taxa excluding snakes, as these leukocytes are morphologically, and likely functionally, similar in most reptile species; upon combining these two leukocytes the difference between migratory versus resident turtles is not statistically significant. Nevertheless, the difference in ABS Lymphs remains.…”

“…Establishment of RIs also permits assessment of compromised health status due to anthropogenic or environmental disturbances (Kelly et al , 2015). Stacy et al (2017) utilized previously established RIs and expert clinician-based assessments to characterize the health status of marine turtles impacted by the BP Deep Water Horizon oil spill. Physiological status of oiled turtles was monitored by documenting blood biochemistry and haematology throughout the rehabilitation period to assess the full breadth of impact of crude oil exposure and the likelihood of full recovery.…”

Pre-/analytical factors affecting whole blood and plasma glucose concentrations in loggerhead sea turtles (Caretta caretta)

“…Processing and analytical effects on blood glucose in sea turtles effects of pre-analytical factors can potentially alter clinical decisions in rehabilitating patients or interpretation of population-level data. Blood glucose concentrations in loggerhead sea turtles vary greatly depending on age and health status, with adults, particularly adult nesting females, typically having lower glucose compared to younger life stage classes [30][31][32][33][34][35], and foraging loggerheads having higher glucose than nesting or stranded turtles [36,37]. The comparison of blood glucose data across studies should be made with caution.…”

“…Hence, refrigerated whole blood samples stored for 2h or longer did not produce reliable blood glucose results by EasyTouch1. Given that the POC glucometer tends to overestimate plasma glucose [38], glucose measurements close to the lower end of published reference intervals for loggerhead sea turtles [31][32][33][34][35]37] should be considered hypoglycemic or at risk for hypoglycemia. These considerations emphasize the need for POC glucometer samples to be processed immediately after sample collection.…”