Mangrove swamps, Nemakia (Madagascar)
38
Manihot esculenta (Euphorbiaceae), used
in semi-intensive cage culture 221-2
Manual sexing, all-male populations 191
minimum size of fish 191
Manure, in pond culture 197-8
Manyara (Tanzania), introductions and
altitude 36
Market preferences, and aquaculture 186
Mash versus pelleted feeds 228
Mass mortalities, in L. Chilwa 99
Mass production, of fry and fingerlings
215-6
of hybrid tilapia fry 317-29
of seed 348-9
Massive fish kills, examples given 40
in various waters 109
Maternal mouthbrooders 6-7
Maturation, flexibility of timing 339
in relation to environmental factors 337
Maturation size, and condition in S. nilo-
ticus 89
declined for S. niloticus in L. George 90
in S. leucostictus 90
Maturity (first), delayed in Malawi flock
species 98
length and condition in S. niloticus 89
length at in S. leucostictus 90
Mauritius, ecological effects of introduc-
tions and transfers 55,57
introductions 30
Maximtm carrying capacity of a cage,
factors influencing 212
Maximum size, for 17 species 74-5
MCC, see Maximum carrying capacity
Megalops cyprinoides, a predator on
young tilapias 313
Melanoides tuberculata, a molluscan
host for digenean parasites 251
'melanopleum', confusion caused by
introductions 25
Meristic characters, in T. zillii and T.
rendalli 5-6
Metabolic studies, S. mossambicus
160-1
T. rendalli 160-73
Metabolism, and daily variations in
temperature 160
feeding and growth 157-80
Metacercariae, wide range recorded in
tilapias 250
Metepa, a chemosterilant to control
reproduction 314
Methallibure, used to suppress gonad
development 312-4
Methyltestosterone, and sex reversal
311-2
Mexico, introductions 28-30
Microcystis, and high primary pro-
duction in L. George 109 '
Micropterus salmoides, a predator on
young tilapias 313
Migration, S. lidole in L. Malawi 52, 54
S. macrochir in L. Mweru 52, 54
S. variabilis in L. Victoria 52
Milkfish, see Chanos chanos
Mirror carp, see Cyprinus carpio
Mixed species, in intensive cage culture
236
Moist pelleted feeds, intensive cage
culture trials 228-9
Monoculture, all-male hybrids 291-6
feeding rate chart 200
more rational at high stocking
densities 195
yields of all-male hybrids 196-7
Monogenean parsites 250
Monosex culture, and control of repro-
duction 310-2
and manual sexing 191
and monosex hybrid production
310-11
and sex reversal 311-2
Monosex male populations, methods to
obtain 191
Monosex populations, of S. niloticus in. intensive cage culture 232-3
in cage culture 213
Monthly specific growth rate 218-9
Mortalities, and algal blooms 257
in cage culture 238-9
and digenean infections 251
examples of massive fish kills 40
and gram-negative bacterial septi-
caemias 255
haemorrhagic septicaemias 255-6
and high density culture 260
infections of Gyrodactylus spp. 250
and Lernaea 253
and mycotic infections 256
and parasitism in S. mossambicus 249
and parasitism in S. niloticus 236
S. niloticus and dissolved oxygen 237
Mosquitos, controlled by introductions
24
Mouthbrooders, behavior of alevins 47
behavior described 6,47
breeding arenas 47