SRAC Tilapia Fact Sheet.

http://srac.tamu.edu/tmppdfs/329734-283f...98ffb8f54665a6d

Water temperature
The intolerance of tilapia to low
temperatures is a serious constraint
for commercial culture in temperate
regions. The lower lethal temperature
for most species is 50 to 52 F
for a few days, but the Blue tilapia
tolerates temperatures to about
48 F.
Tilapia generally stop feeding when
water temperature falls below 63 F.
Disease-induced mortality after handling
seriously constrains sampling,
harvest and transport below 65 F.
Reproduction is best at water temperatures
higher than 80 F and does
not occur below 68 F. In subtropical
regions with a cool season, the number
of fry produced will decrease
when daily water temperature averages
less than 75 F. After 16- to 20-
day spawning cycles with 1/2-pound
Nile tilapia, fry recovery was about
600 fry per female brooder at a water
temperature of 82 F, but only 250
fry per female at 75 F.
Optimal water temperature for
tilapia growth is about 85 to 88 F.
Growth at this optimal temperature
is typically three times greater than
at 72 F.