Morphologic and Cytochemical Characteristics of the Blood Cells of the Yellow-Bellied Slider (Trachemys scripta scripta)

Abstract

The increasing prevalence of yellow-bellied sliders (Trachemys scripta scripta) as pets in the European Union and also its utilization as animal models for experimental purposes makes crucial an accurate classification of their blood cells. The aim of this work was to provide a morphologic classification based on the cytochemical characteristics of the blood cells of 15 yellow-bellied sliders. Cytochemical stains included benzidine peroxidase, chloroacetate esterase, alpha-naphthyl butyrate esterase (with and without sodium fluoride), acid phosphatase (with and without tartaric acid), Sudan black B, periodic acid-Schiff and toluidine blue. Nuclear and cellular dimensions were also measured based on quick Romanowsky-type stained smears. Besides erythrocytes and thrombocytes, five types of white blood cells were identified: heterophils, eosinophils, basophils, lymphocytes and monocytes. The cytochemical patterns of heterophils, eosinophils and basophils were unique compared to those described for other chelonians. This paper provides a useful guideline for clinical settings and further haematological studies of this species.

Morphology and cytochemical patterns of peripheral blood cells of tiger frog (Rana rugulosa)

“…Neutrophils are important phagocytes and they are also vitally important in the immune system ( Roos, Voetman & Meerhof, 1983 ). In this study, neutrophils were strongly positive for ACP, SBB, and positive for PAS and POX staining, this cytochemical pattern was similar to that described in human, some reptiles and amphibians ( Xu et al, 2005 ; Casal & Orós, 2007 ; Chansue et al, 2011 ; Cooper-Bailey et al, 2011 ; Bricker, Raskin & Densmore, 2012 ; Hernández et al, 2017 ). The strongly positive for ACP, SBB, and positive for PAS and POX staining indicated that tiger frog neutrophils may have a strong capability of phagocytosis and bactericidal effect.…”

“…However, there were great differences in their morphology. Mammalian platelets are enucleated and mostly round to oval disk-shaped ( Salakij et al, 2000 ; Prihirunkit et al, 2007 ; Techangamsuwan et al, 2010 ), while thrombocytes in lower vertebrates mostly present round, teardrop, fusiformis or spindle in shape, with a nucleus ( Salakij et al, 2002 ; Chansue et al, 2011 ; Bricker, Raskin & Densmore, 2012 ; Fang et al, 2014 ); The thrombocytes of the tiger frog mostly presented long rods or spindle in shape with clear edges and distinct boundaries between nucleoplasms, this morphological characteristics was in accord with that described in American bullfrog ( Bricker, Raskin & Densmore, 2012 ) and king cobra ( Ophiophagus hannah ) ( Salakij et al, 2002 ), but different from dubois’s tree frog ( Madhusmita & Kumari, 2014 ), yellow-bellied slider ( Trachemys scripta scripta ) ( Hernández et al, 2017 ) and captive bobtail lizard ( Tiliqua rugosa ) ( Moller, Gaál & Mills, 2016 ), whose thrombocytes often presented round or oval in shape.…”

“… Fang et al (2014) and Fathinia et al (2020) have conferred that the erythrocyte size could reflect the position of a species on the evolutionary scale: the erythrocyte size in lower vertebrates was larger than that in higher vertebrates. However, in our study, the erythrocyte size in tiger frog was smaller than that in some reported reptiles ( Table 4 ), such as European pond turtle ( Emys orbiculuris ), Mediterranean pond turtle ( Muarremys leprosu ) and yellow-bellied slider ( Trachemys scripta scripta ) ( Perpiñán & Sánchez, 2009 ; Hernández et al, 2017 ), it was also smaller than that in American bullfrog ( Rana catesbeiana ) and Chinese toad ( Bufo gargarizans ) ( Jin et al, 2015 ). Guo et al (2002) have shown that the smaller the erythrocyte, the stronger of its capacity for oxygen transport.…”

“…Erythrocytes play a major role in transporting oxygen and carbon dioxide ( Peng et al, 2018 ; Fathinia et al, 2020 ). The mature erythrocytes of tiger frog presented elliptic or long oval in shape with an abundant and faint red-stained cytoplasm free of granules, which were similar to those of non-mammalian vertebrates ( Bricker, Raskin & Densmore, 2012 ; Fang et al, 2014 ; Tang et al, 2015 ; Hernández et al, 2017 ). Fang et al (2014) and Fathinia et al (2020) have conferred that the erythrocyte size could reflect the position of a species on the evolutionary scale: the erythrocyte size in lower vertebrates was larger than that in higher vertebrates.…”

“…At present, the classification, morphology and cytochemistry of peripheral blood cells have been generally investigated in various vertebrates, especially in human and mammals ( Salakij et al, 2000 ; Techangamsuwan et al, 2010 ; Fang et al, 2014 ; Hernández et al, 2017 ). Amphibians are the transitional group of vertebrates from aquatic to terrestrial mode of life.…”