The Company of Biologists

Table 3.

Kinetic variables for Na⁺ and Cl^- influx in stingrays acclimated to either ion-poor Rio Negro water (soft water) or ion-rich hard water

	Ion-poor Rio Negro water (N=7)	Ion-rich hard water (N=6)
K_m^Na (μmol l^-1)	468±100	331±86
J_max^Na (μmol kg^-1 h^-1)	443±67	523±75
K_m^Cl (μmol l^-1)	472±55	385±58
J_max^Cl (μmol kg^-1 h^-1)	773±93^{^†}	982±148^{^†}

	Ion-poor Rio Negro water (N=7)	Ion-rich hard water (N=6)
K_m^Na (μmol l^-1)	468±100	331±86
J_max^Na (μmol kg^-1 h^-1)	443±67	523±75
K_m^Cl (μmol l^-1)	472±55	385±58
J_max^Cl (μmol kg^-1 h^-1)	773±93^{^†}	982±148^{^†}

Values are means ± 1 S.E.M.

There were no significant differences (P>0.05) in corresponding variables between the two acclimation treatments.

Significantly different (P≤0.05) from corresponding value for Na⁺.