Heavy metals, hematology, plasma chemistry, and parasites in adult hellbenders (Cryptobranchus alleganiensis)

Abstract

Ozark (Cryptobranchus alleganiensis bishopi) and eastern hellbenders (C. a. alleganiensis) from seven rivers in Missouri, USA, were collected to investigate essential information on hematology, parasites, and plasma chemistry and levels of select heavy metals (Hg, Pb, Cd, Cr, and Co) in the animals' blood. The body masses of Ozark hellbenders were much smaller than those of eastern hellbenders. Blood parasites were detected in Ozark hellbenders, but not eastern hellbenders. The higher frequency in occurrence of eosinophils in Ozark hellbenders (8.8-16.8%) than in eastern hellbenders (highest at 6.6%) might result from the infection of parasites. Seven of the 18 hematology and plasma parameters (hematocrit, basophils, eosinophils, K, P, Ca, and chloride) showed significant differences between subspecies. The blood levels of heavy metals Co, Hg, and Pb differed significantly between subspecies. Ozark hellbenders had higher blood levels of Co (p<0.001), while blood levels of Hg and Pb were higher in eastern hellbenders. The levels of chromium (Cr) and cadmium (Cd) were not different between subspecies and among rivers. The eastern hellbenders at Niangua River and the Ozark hellbenders at the North Fork of the White River had lower Hg levels compared to eastern and Ozark hellbenders at other sites. All together, our findings provide important baseline information for managing this endangered species.

Evidence of ectoparasite-induced endocrine disruption in an imperiled giant salamander, the eastern hellbender (Cryptobranchus alleganiensis)

“…Eosinophils are important in immune responses against parasitic infection, which is consistent with their increased abundance in parasitized hellbenders (Eales, 1997;Davis and Hopkins, 2013, and citations therein). Our findings are consistent with a previous study which found a higher occurrence of eosinophils in parasitized Ozark hellbenders versus non-parasitized eastern hellbenders (Huang et al, 2010). Though we did not detect a significant effect of leeches on N:L ratios in our repeated measures model, N:L ratios at the time of capture (0 h) were 25% higher in individuals harboring leeches, which is consistent with known shifts in N:L ratios that occur in response to infections in other animals (Davis et al, 2008).…”

“…1). Previous studies have documented leeches on Ozark hellbenders (Dundee and Dundee, 1965;Nickerson and Mays, 1973;Moser et al, 2008;Huang et al, 2010;Bodinof et al, 2012); however, only recently have leeches been detected in populations of the eastern hellbender (Hopkins and DuRant, 2011;Davis and Hopkins, 2013;Hopkins et al, 2014). Genetic analyses revealed that this leech is a new species in the genus Placobdella, and is distinct from the species of leech that parasitizes Ozark hellbenders (Hopkins et al, 2014).…”

Health and Habitat Quality Assessment for the Eastern Hellbender (Cryptobranchus Alleganiensis Alleganiensis) in Indiana, Usa

“…Males, however, had significantly higher potassium, which, although not explicitly stated, was a pattern in Solis et al (2007a). In general, our numbers were similar to those reported from populations of eastern hellbenders with a few noticeable exceptions (Solis et al, 2007a;Huang et al, 2010). In our study, AST, CK, and uric acid (UA) values were considerably lower than those found in Solis et al (2007a), although only the AST and CK differed from that found by Huang et al (2010).…”

“…In general, our numbers were similar to those reported from populations of eastern hellbenders with a few noticeable exceptions (Solis et al, 2007a;Huang et al, 2010). In our study, AST, CK, and uric acid (UA) values were considerably lower than those found in Solis et al (2007a), although only the AST and CK differed from that found by Huang et al (2010). Aspartate aminotransferase originates from the liver, heart, and skeletal muscle and can indicate liver disease.…”

Cryptic impacts of temperature variability on amphibian immune function

“…We were surprised by the predominance of lymphocytes (>80% of immune cells in every sample), as well as the consistency of leukocyte ratios among individuals and over time. These findings contrast with the more variable proportions of circulating lymphocytes (~35-65%), neutrophils (~20-45%) and eosinophils (~3-20%) previously reported in C. alleganiensis (Huang et al, 2010;Jerrett and Mays, 1973;Solís et al, 2007). Because previous studies have focused on wild-caught adults, these differences could be related to environmental variables or animal age.…”