5ml*2.17g/ml gives you 10.85 gm. Dissolve this in 100 ml of DI H2O (you can usually find it in a drug store, people like to fill steam irons with it for example). This is your 10.85% NaCl stock. Now add 7 ml of this stock to 93 ml of DI H2O and you should be close (7/100 total dilution of 10.85% should get you to 0.76%). Now if you can just sterilize it, you can set up your own amphibian fluid replacement therapy ward, complete with tiny froggy IV bags...Pau, yes, you can buy mammalian physiological saline, but I haven't seen amphibian saline sold in many stores...
Consulting my old copy of Prosser, Comparative Animal Physiology, there's a list of balanced salt solutions for all kinds of creatures. The NaCl concentrations are a bit lower than for plain saline, to take into account the osmotic effects of the other (e.g. KCl) ingredients, but should be close enough for you.
Avian Ringers has 117 mM, equivalent to ~0.69%
Frog Ringers has 112 mM, equivalent to ~0.66%
Crayfish 207 mM, equivalent to ~1.2%, seems a bit high, but that's what the book says.... Cockroach ~1.24%
If you are looking at blood, the red cells appearance will tell you if your saline is at physiological concentration for your particular animal, too dilute (hypoosmotic) or too concentrated (hyperosmotic). If the RBCs are looking shrunken, with scalloped borders, your solution is too strong. If they swell up and even potentially burst, its too weak.
David
