Table 1 Sample calculations used for modeling eye and brain costs for a 4-g fish.
PachónMicosSurfaceData origin
aWhole-body minimal metabolic rate
(mg O2 hour−1 per 5-g fish)
0.8328*0.9291.026*Published data
bWhole-body oxygen demand (mg O2 hour−1)0.6860.7660.846a(4 g ÷ 5 g)0.862
cBrain mass (g)0.0270.0310.0344 g × organ mass scaling
relationships in table S2
dRelative brain mass (% body weight)0.680.780.85c ÷ 4 g
eBrain metabolic rate (mg O2 hour−1 g wet mass−1)1.6031.6031.603Data from the current study
fBrain oxygen demand (mg O2 hour−1)0.0430.0500.055e × c
gRelative brain cost (% body O2 demand)6.276.526.50f ÷ b
hEye mass (g)00.0380.0904 g × organ mass scaling
relationships in table S2
iRelative eye mass (% body weight)00.952.25h ÷ 4 g
jEye metabolic rate (mg O2 hour−1 g wet mass−1)00.5250.525Data from the current study
kEye oxygen demand (mg O2 hour−1)00.0200.047j × h
lRelative eye cost (% body O2 demand)02.615.56k ÷ b
mNeural tissue (eyes plus brain) oxygen demand
(mg O2 hour−1)
0.0430.0700.102f + k
nNeural tissue cost (% body O2 demand)6.279.1412.06m ÷ b
oCost of vision (% body O2 demand)03.526.97(mMicosmPachón) ÷ bMicos
(msurfacemPachón) ÷ bsurface

*Data taken from Moran et al. (19).

†Estimated as a rate equidistant between Pachón and surface ecotypes based on data from Hüppop (11).

‡Mass metabolism scaling exponent (0.862) taken from Moran et al. (19).