Variation in the erythrocyte size among larvae, juveniles and adults of Hypsiboas cordobae (Anura, Hylidae)

Abstract

We aimed at determining sizes and shape of erythrocytes and evaluating the differences among larva, juvenile and adult Hypsiboas cordobae. Length and width of 40 randomly chosen erythrocytes and their respective nuclei from individuals of different ages collected in the experimental field "Las Guindas" (Córdoba, Argentina) were measured. Erythrocyte and nuclear areas were estimated assuming an ellipsoidal shape, and the aspect ratio, which reflects the shape of the cell, was calculated. The erythrocytes were oval, and their nuclei were also oval and centrally located. Erythrocyte size increased with age, whereas nuclei were larger in tadpoles than in juveniles. The cell and nucleus shapes also changed with age from the spherical shape in larvae to the more ellipsoidal one in adults. Discriminant analysis confirmed the existence of highly significant (P < 0.0001) differences in erythrocyte and nuclear areas among larvae, juveniles and adults, with a classification rate of 93.33%.

Evolution of erythrocyte morphology in amphibians (Amphibia: Anura)

“…Toads mainly inhabit terrestrial environments, whereas frogs inhabit semi-aquatic or aquatic environments (GÜL et al 2011). The terrestrial habitat has selected a series of adaptive structures and mechanisms in frogs that have enabled them to function under conditions of changeable humidity and partial oxygen pressure in terrestrial environments (BARAQUET et al 2013, FOXON 1964, WOJTASZEK & ADAMOWICZ 2003. Second, erythrocyte size may be dependent on the level of metabolism in vertebrates (WOJTASZEK & ADAMOWICZ 2003).…”

“…Hematological parameters vary significantly among amphibian species (ARIKAN et al 2010, BARAQUET et al 2013). For example, OLMO & MORESCALCH (1975) documented that interspecific variation is significant in the volume of erythrocytes and nuclei of seven Plethodontidae (Amphibia: Urodela) species.…”

Male spiny frogs enter the underwater battlefield with loose skin exhibiting enhanced penetration of capillaries into the epidermis

“…Intraspecific comparisons of L. boringii may further facilitate a more comprehensive understanding of the role of erythrocyte size in the enhancement of respiration in amphibians. Smaller red blood cells have higher surface/volume ratios, allowing for more efficient gas exchange, and some amphibian species have been reported to reduce their red blood cell size to augment respiration [ 33 , 34 ]. This strategy may have little impact on their cutaneous oxygen exchange, which is likely diffusion limited because in contrast to the respiratory membranes of lungs and gills, the skin epidermis is too thick for rapid transfer of oxygen [ 1 , 12 , 35 ].…”

Effects of Altitude and Temperature on Erythrocyte Morphology of Emys orbicularis (Linnaeus, 1758) and Mauremys rivulata (Valenciennes, 1833)

“…The variation in erythrocyte sizes with regard to altitudinal differences may be explained by the effect of surface on gas exchange; for example, a small blood cell permits more gas exchange than a larger one. As in anurans, the ones that live at higher altitudes have smaller erythrocytes (Baraquet et al, 2013). Temperature is another important factor that affects the blood parameters and the number of the red blood cells.…”