Chemical Anatomy of the Pericardial and Perivisceral Fluids of the Stingray, Dasyatis Americana

Abstract

The significance of the observation by Staedeler and Frerichs (1858) of "colossale Quantitaten" of urea in the blood and tissues of some skates and a shark remained obscure for four decades. In 1897 Bottazzi reported that the freezing point depressions of elasmobranch blood and of sea water were approximately equal, that is, they had approximately the same total solute particle, or osmolal, concentrations. But whereas sodium and chloride make up the bulk of solute particles in sea water, Rodier (1899) observed that urea accounted for about one-third of the solute particles of elsamobranch blood. Rodier also noted that the freezing point depression of the fish blood was generally slightly greater than that of the animal's sea-water environment, an observation which has been re-

Urea and Trimethylamine Oxide Levels in Elasmobranch Embryos

“…water in yolks). Values for urea concentration in the embryos are within the range of urea levels found in various body fluids of adult elasmobranchs (see Bernard et a!., 1966). Differences in water content may also help to explain the greater average density of the yolks (1.15 mg./ml.)…”

Acute stress response of Kootenai River white sturgeon Acipenser transmontanus Richardson reflected in peritoneal fluid and blood plasma

“…Similar to the Elasmobranchii, the composition of white sturgeon PF relative to BP is indicative of a modified ultrafiltrate (Bernard et al , 1966). This is also consistent with the composition of mammalian PF relative to BP (Tortora & Evans, 1986).…”

“…A lower protein and cortisol level in PF than in BP has been similarly reported by Barannikova et al (2002) on spawning stellate sturgeon Acipenser stellatus Pallas. Marine stingrays Dasyatis americana Hildebrand & Schroeder have also been shown to contain a lower protein level in PF than in BP (Bernard et al , 1966). However, unlike sturgeon in the current study, electrolyte levels of BP and PF in stingray were dissimilar.…”

“…A decrease in pericardial pressure and pericardial fluid loss, via the PPC, increases stroke volume indicating a possible interdependence between heart function and peritoneal fluid (Shabetai et al , 1985; Lai et al , 1996). In Elasmobranchii PF is considered to be an ultrafiltrate of BP (Bernard et al , 1966); it was hypothesized that the same would be true of sturgeons. The aims of the current study were to (1) characterize the composition of PF, (2) investigate whether physiological indicators in BP are similarly reflected in PF following a standard stressor and (3) assess their potential for use in development of nanosensor‐enhanced PIT tags.…”

Comparison of some parameters of serum and uterine fluid of pregnant, viviparous sharks (Carcharhinus leucas) and serum of their near-term young

“…However, only a trace of protein was found in the two uterine fluid samples analyzed for protein, whereas the adult serum averaged 3·2 g % in three females. In its lack of protein, the uterine fluid resembles perivisceral and pericardial fluids, which also are virtually free of protein in elasmobranchs (Bernard et al, 1966;Thorson, 1967).…”