Fig. 3. The relationships between Cl- efflux
(JoutCl) and external Cl-
concentration ([Cl-]ext) in stingrays acclimated to
either ion-poor Rio Negro water (soft water, triangles and solid line,
N=7) or ion-rich hard water (circles and dashed line, N=6).
Values are means ± 1 S.E.M. There was a specific significant difference
between the two relationships (*P
0.05) only around 300
µmol l-1. The thicker line shows the uptake kinetic relationship
for JinCl from
Fig. 1, and the arrows mark the
intersection points of balance where
JinCl=JoutCl.