|Oxygen-transporting properties of the blood of two semi-terrestrial amphipods, Orchestia gammarellus (Pallas) and O. mediterranea (Costa)|Taylor, A.C.; Spicer, J.I. (1986). Oxygen-transporting properties of the blood of two semi-terrestrial amphipods, Orchestia gammarellus (Pallas) and O. mediterranea (Costa). J. Exp. Mar. Biol. Ecol. 97(2): 135-150. hdl.handle.net/10.1016/0022-0981(86)90115-2
In: Journal of Experimental Marine Biology and Ecology. Elsevier: New York. ISSN 0022-0981, more
Crustacea; Amphipoda; respiratory physiology; haemocyanin; oxygen transport; Orchestiagammarellus; Orchestia mediterranea
|Authors|| || Top |
- Taylor, A.C.
- Spicer, J.I.
The results of a comparative study of the oxygen-transporting properties of the blood of two supralittoral amphipods, Orchestia gammarellus (Pallas) and O. mediterranea (Costa) are presented. The concentrations of the major ions in the blood were similar in the two species although in O. mediterranea the concentrations of Na+ and Cl- ions were lower than in O. gammarellus. The oxygen-carrying capacity of the haemocyanin was quite low (0.7 ml. 100 ml-1) and did not differ significantly between the two species. The blood of both species had a moderately high oxygen affinity which remained almost independent of temperature in the range 10–18°C. The P50 at the in vivo pH (7.8) was 9.7 and 10.3 Torr, respectively, at 10°C. The Bohr factor (? log View the MathML source) was almost identical in the two species (mean = -0.84). The cooperativity of the haemocyanin was also similar in both species (n50 = 3) and was largely independent of pH within the pH range 7.2–7.8.It was found, however, that O. gammarellus collected from the upper limits of their distribution on the shore (above high water animals, AHW) had a blood ion composition that was very different from that of animals taken from the middle of their distribution (below high water animals, BHW). The concentrations of Na+, Cl- and Ca2+ ions in particular were very much lower in the blood of animals from high on the shore and the pH of the blood was significantly lower (7.63 compared with 7.83). As a result, the in vivo oxygen affinity of the blood of AHW animals was much lower than that of BHW animals. When measured at constant pH, the oxygen affinity of the blood of AHW animals was still lower than that of BHW animals. Experiments in which blood from the two groups of animals was dialysed against different physiological salines, showed that this could be attributed almost entirely to the lower Ca2+ ion concentration in the blood of AHW animals. The oxygen-transporting properties of the blood are discussed in relation to the ecology of these species.