170
C. F. HICKLING
matter, or detritus, nourishes directly or indirectly a rich fauna including fish, such as the small species of Cyprinodon and Atherina,
which are good food for the eels. I n such rich muds, chironomid larvae,
which are also good food for the eels, would abound, and no doubt a
proportion of the grey mullet young are also taken by the eels.
The food of prawns, according to Schuster, is partly animal matter
found on the bottom of the ponds, and partly unicellular algae of different kinds, as well as detritus. They feed mainly at night and burrow
in the mud by day. Hall (1962) shows that penaeid prawns, while
generally omnivorous, show preferences for polychaetes, crustaceans,
or a general carnivorous diet, or for vegetable matter. The three species
of Penaeidae which are of the greatest importance in the Singapore
prawn ponds do not compete for food. Penueus indicus (H. Milne
Edwards) feeds mainly on large crustaceans, Metupenueus ensis (de Haan)
is chiefly vegetarian and so is the fourth most important, Metapenaeus
brevicornis (H. Milne Edwards). M . mastersii (Haswell) is omnivorous,
but with a preference for the appendages of large crustaceans.
The “ sugpo ” of the Philippine prawn ponds Penaeus monodon
(Fabr.), feeds on the blue-green algal felt so important as a fish food.
But supplementary foods are also given (Caces-Borja and Rasalan,
1967). The fry are given rice bran and care is taken to see that filamentous algae which would entangle the fry do not develop in the fry ponds.
The older ‘‘ sugpo ” are given, as supplementary food, fish, meat and
small crabs, which may be ground up and piled in a corner of the pond
or some fish is lightly boiled and placed along the shores of the pond,
where the prawns can start feeding in the evening.
B. Culture of algal pasture
Clearly, success in brackish-water fish farming must lie in encouraging and enhancing the production of useful benthic plants, and their
associated animals and detritus, in shallow water. In Italy and Arcachon and in the Russian limans, no measures seem t o be taken. The
ponds are too big for such measures in Italy and Russia, and they
cannot be drained out completely. So the operators must rely on
natural fertility and stock the optimum number of fish, and try to
eliminate predators and competitors.
Hiatt (1944) and Malone (1969) studied the Hawaiian fishponds,
where, according to Cobb (1901), no culture takes place, with a view
to suggesting ways of improving the productivity of these ponds, and
so of halting the decline of the fishpond industry in Hawaii. Both
authors agreed that turbidity was a restricting factor in the productivity
C. F. HICKLING
matter, or detritus, nourishes directly or indirectly a rich fauna including fish, such as the small species of Cyprinodon and Atherina,
which are good food for the eels. I n such rich muds, chironomid larvae,
which are also good food for the eels, would abound, and no doubt a
proportion of the grey mullet young are also taken by the eels.
The food of prawns, according to Schuster, is partly animal matter
found on the bottom of the ponds, and partly unicellular algae of different kinds, as well as detritus. They feed mainly at night and burrow
in the mud by day. Hall (1962) shows that penaeid prawns, while
generally omnivorous, show preferences for polychaetes, crustaceans,
or a general carnivorous diet, or for vegetable matter. The three species
of Penaeidae which are of the greatest importance in the Singapore
prawn ponds do not compete for food. Penueus indicus (H. Milne
Edwards) feeds mainly on large crustaceans, Metupenueus ensis (de Haan)
is chiefly vegetarian and so is the fourth most important, Metapenaeus
brevicornis (H. Milne Edwards). M . mastersii (Haswell) is omnivorous,
but with a preference for the appendages of large crustaceans.
The “ sugpo ” of the Philippine prawn ponds Penaeus monodon
(Fabr.), feeds on the blue-green algal felt so important as a fish food.
But supplementary foods are also given (Caces-Borja and Rasalan,
1967). The fry are given rice bran and care is taken to see that filamentous algae which would entangle the fry do not develop in the fry ponds.
The older ‘‘ sugpo ” are given, as supplementary food, fish, meat and
small crabs, which may be ground up and piled in a corner of the pond
or some fish is lightly boiled and placed along the shores of the pond,
where the prawns can start feeding in the evening.
B. Culture of algal pasture
Clearly, success in brackish-water fish farming must lie in encouraging and enhancing the production of useful benthic plants, and their
associated animals and detritus, in shallow water. In Italy and Arcachon and in the Russian limans, no measures seem t o be taken. The
ponds are too big for such measures in Italy and Russia, and they
cannot be drained out completely. So the operators must rely on
natural fertility and stock the optimum number of fish, and try to
eliminate predators and competitors.
Hiatt (1944) and Malone (1969) studied the Hawaiian fishponds,
where, according to Cobb (1901), no culture takes place, with a view
to suggesting ways of improving the productivity of these ponds, and
so of halting the decline of the fishpond industry in Hawaii. Both
authors agreed that turbidity was a restricting factor in the productivity