Blood Rheology in Marine Mammals

Abstract

The field of blood oxygen transport and delivery to tissues has been studied by comparative physiologists for many decades. Within this general area, the particular differences in oxygen delivery between marine and terrestrial mammals has focused mainly on oxygen supply differences and delivery to the tissues under low blood flow diving conditions. Yet, the study of the inherent flow properties of the blood itself (hemorheology) is rarely discussed when addressing diving. However, hemorheology is important to the study of marine mammals because of the critical nature of the oxygen stores that are carried in the blood during diving periods. This review focuses on the essential elements of hemorheology, how they are defined and on fundamental rheological applications to marine mammals. While the comparative rationale used throughout the review is much broader than the particular problems associated with diving, the basic concepts focus on how changes in the flow properties of whole blood would be critical to oxygen delivery during diving. This review introduces the reader to most of the major rheological concepts that are relevant to the unique and unusual aspects of the diving physiology of marine mammals.

Hematological convergence between Mesozoic marine reptiles (Sauropterygia) and extant aquatic amniotes elucidates diving adaptations in plesiosaurs

“…The prevalence of enlarged RBCs in deep diving flying species, such as the blue-eyed shag, which would otherwise benefit from smaller cells, further supports an adaptive value of this trait. Apart from this, enlarged RBCs have been controversially hypothesized to be advantageous for pelagic specialists by altering blood rheology (Block & Murrish, 1974; Castellini et al, 2010). In amniotes, RBC size is inversely correlated with RBC counts (Hartman & Lessler, 1963; Hawkey et al, 1991).…”

Hematologic and Biochemical Reference Interval Development and the Effect of Age, Sex, Season, and Location on Hematologic Analyte Concentrations in Critically Endangered Yangtze Finless Porpoise (Neophocaena asiaeorientalis ssp. asiaeorientalis)

“…These differences reinforce similar results, across a smaller sample size, in several hematological analytes, between mean concentrations found in animals residing in these two diverse locations (Nabi et al, 2017a). Many reasons including diseases, nutrition, and parasitic infestation can cause variation in the blood cell concentrations (Bossart et al, 2001; Castellini et al, 2010; Shiozaki and Amano, 2017). Similarly, the inflammatory cells (WBC, lymphocyte, monocyte, eosinophil, and basophil) were significantly higher in the PL vs. TZO as observed in the two studies by Nabi et al (2017a,b).…”

Quantitative characterization of endothelial cell morphologies depending on shear stress in different blood vessels of domestic pigs using a focused ion beam and high resolution scanning electron microscopy (FIB-SEM)

“…Blood viscosity of this haematocrit percentage at high shear rate can be found in the literature (Castellini et al, 2010). The blood wall shear stress ( ) in these arteries was determined due to volume blood flow rate (Q), vessel diameter (d) and assumed blood viscosity of 3.5 cP (Castellini et al, 2010) using following equation:…”