Ich or white spot 248
Ichthyophthirius multifiliis, the cause of
Ich or white spot 248
Ichthyobodo necatrix, in S. mossam-
bicus? 249
Ictalurus punctatus, cotnpared with
tilapias in culture systems 245
Idaho (U.S.A.), T. zillii in geothermal
water 31
Immune system, disease and cold
temperature discussed 262
Immunological studies, and speciation
in Sarotherodon and Tilapia
discussed 12-13
Indigenous populations, interactions
with introductions 57
Indonesia, intensive cage culture
with mixed species 236
introductions 28, 57
Information resources, need to
improve 354
Inhibition, of reproduction by high
stocking densities 313
Inhibitory factor, and high density
culture 260
Inorganic fertilization and manuring, in
pond culture 197-8
yields increased by 2% 197
Inorganic fertilizers, and all-male
hybrid production summarized 295
Integrated farming, and tilapia culture
350
Integrated farming systems, and pond
culture 198, 293
Intensive cage culture 223-36
costs of artisanal feeds 226
costs and income 234
and Edwardsiella tarda infections 255
examples 230-6
feed 223-6
feed conversion 228-30
feed presentation 228
feeding rate 225-7
feeding techniques 227
mixed species 236
trials with different pelleted feeds
228-9
Internal factors, and regulation of repro-
ductive activity 135-9
International Biological Programme,
study of L. George 108-9
Interspecific spawnings 321-5
advantages of more males 323
problems of incompatibility due to
behavior 322-5
see also Hybridization, Hybrids
Intestine, exceptionally long in tilapias
14 2
structure and herbivorous diet 3
Introductions, Africa 24-5, 86
Africa (noncontinental) 28-30
African waters summarized 26, 86
America 28-31
apperance of transplanted species
333-4
to artificial lakes in Shaba 24
to artificial water bodies 24,86
Asia 28-30
Asia (SE) 30-1
Bangladesh 28-9, 57
Belgium 29,31
and biological control 24
Bolivia 30
Brazil 30, 57
cause for concern 354
China 28
Colombia 28, 30
complete failures 55
confused with natural distribution 25
cooling waters 25
Cyprus 29
destruction of vegetation and native
species 29
eastern rivers north of the Zambezi 6
ecological effects 55-7
Ecuador 28
El Salvador 28-30
established rapidly from very few
fry 91
Europe 29-31
factors affecting success in man-made
lakes 50
factors responsible for failures 55
failure attributable to excessive repro-
duction 56
failure in cold regions 55
failure at high altitude 55
failure with various species 55
Fiji 30
and fish culture 24
and fisheries 24
followed by escapes 24
to geothermally heated waters 25
Germany 30
Great Britain 31
Grenada 28