unfavorable consequences of intro-
ductions 57
Tambaqui, see Colossoma macropomum
Tanks, various types used in fingerling
production 282-3
Taxonomy, behavioral and geographical
evidence 7
merits of subgenera discussed 7-8
and speciation 3-13
use of subgeneric names 7
Teeth, described 142
structure and herbivorous diet 3
S. franchettii 7
S. karomo 8
S. niloticus 4
S. tanganicae 7
T. nariae 4
T. zillii 4
Temperature, and assimilation by T.
rendalli 168-9
and breeding 44-5
cold tolerance of hybrids 298
daily changes and aquaculture 55
daily variations and metabolism 160
diseases and low temperatures
discussed 262
and dissolved oxygen tolerance
discussed 127
and distribution 33-7, 51-2, 119
and diurnal movements 53
diurnal oscillations and inshore/
offshore movements 159
effect of oscillations on food con-
sumption and growth 172-4
effect on sex ratio of S. aureus 314
effect on spawning 314
and energy cost of feeding 170-1
and excretory energy loss 171
extremes and myxobacterial infections
254
and failure of introductions 55
and feed conversion ratios 230
food, and growth in T. rendalli 166-8
and gametogenesis 133
and growth in tilapias 189
importance in relation to growth 158
lower limits for 4 species summarized
125
and parasitic infections 248-9
physiological effects summarized
115-6
and precocious spawning in T. zillii
110
preferences discussed 176,178
and seasonal changes in feeding
activity 43
skin repairs at low temperature
discussed 262
and spawning in pond culture 189
systematic studies on preferences
and tolerances needed 58
tolerance of juvenile tilapias in
L. Victoria 93
tolerance of various species 35,120-1
upper lethal levels 37
Temperature oscillations, benefits to
smaller fish 174
Temperature tolerance, and acclimation
121
and aquaculture 37
effect of salinity 37, 121
eurythermal species 37
intraspecific differences 37
and introductions 37
and salinity 37, 121
and size 37
stenothermal species 37
juvenile tilapias in L. Victoria 93
various species 35, 120-1
wide in T. sparrmanii 4
see also Thermal tolerance
Terrestrial plants, used in semi-intensive
cage culture 221-2
Territoriality 46-9
advantages to substrate spawners 48-9
and aggression 49
and wounds 49
Tetramine, a chemosterilant to control
reproduction 314
Thailand, introductions 28-30, 57
S. mossambicus not accepted on
account of its taste 57
Thermal tolerances, tilapias in hot springs
34
various species 35, 37, 120-1
Tihange (Belgium), culture experiments
with nuclear power plant effluent
207,218,220
Tilapia (genus)
and immunological studies discussed
12-13
many species are macrophyte feeders
41
number of species about 30 5,332
Tilapias, ability to switch from growth to
reproduction 109-10