A mystery revealed: an update on eosinophil and other blood cell morphology of the Argentine black and white tegu (Salvator merianae)

Reptile white blood cell (WBC) morphological features are strikingly variable across species. In the Argentine black and white tegu (Salvator merianae), red tegu (Salvator rufescens), and Savannah monitor (Varanus exanthematicus), previous reports described a WBC type with a single distinct, clear, linear- to ovoid- to crescent-shaped inclusion of presumptive monocytic origin. The objective of this study was to further investigate the origin of this unique WBC type with crescent-shaped inclusions. Blood samples from two Argentine black and white tegus, tegu 1, a 4-year-old female, and tegu 2, a 2-year-old presumed male, were submitted for routine hematological evaluation. Additional blood films were prepared and stained with these cytochemical stains: alkaline phosphatase (ALP; naphthol AS-MX phosphate substrate), alpha-naphthyl butyrate esterase, alpha-chloroacetate esterase, myeloperoxidase, Periodic acid-Schiff, and Sudan black B. Blood films from tegu 1 were also stained with a second ALP stain (5-bromo-4-chloro-3-indoxyl-phosphate and nitroblue tetrazolium substrate), Luna, luxol fast blue, and toluidine blue. The blood from tegu 1 was cytocentrifuged to isolate and fix the buffy coat in glutaraldehyde 2.5% aqueous solution for transmission electron microscopy. Six morphologically distinct WBC types were identified from tegu 1, including heterophils, basophils, monocytes, azurophils, lymphocytes, and the unique WBC type, which were identified as eosinophils with inclusions. WBC types in tegu 2 were similar; however, eosinophils lacked a discernable inclusion. Proper WBC identification will be useful in obtaining accurate hemogram data for this species

Physiological Responses to Isolated Auditory and Visual Stimulus versus the Combination of Auditory and Visual Stimulus

An article that appeared in JASS, issue 2018A variety and multitude of stimuli elicit a fear response in humans, including horror films. Fear responses include various physiological alterations such as an increase in heart rate, changes in electrodermal activity (EDA), and an increased respiration rate. The type and intensity of sensory intake from a fear inducing stimulus determines the extent of physiological alterations. In order to understand the effects of auditory and visual stimuli on the fear response, a five minute horror film clip was played for 24 participants. Participants were randomly selected to participate in one of three groups: Group 1 watched the clip with audiovisual stimulus, Group 2 watched the clip with visual-only stimulus, and Group 3 watched the clip with audio-only stimulus. Since the combination of both an auditory and visual stimulus is the most intense form of sensation, it was hypothesized that participants in Group 1 would demonstrate the greatest fear response and show the largest rate of physiological change in EDA, respiration rate, and heart rate. Paired two sample t-tests and one-way ANOVA tests showed there was some statistical significance in the resulting data. Overall, this study supported the hypothesis that bimodal audiovisual fear inducing stimulus would lead to a larger physiological response