ESTUARINE FISH FhRMING
159
Philippines, where the valuable " Sugpo ) ) or Penaeus monodon (Fbr.)
is cultivated in ponds with Chanos or by itself (Caces-Borja and Rasalan,
1967).
As with the young of the other penaeids used in farming, the creeks,
lagoons and other shallow areas are the places where fishing for young
takes place. Fish-lures are used, which take the usual form of bunches
of grass tied along a rope which is moored in shallow water. One man
may operate many of these ropes. The " sugpo " young are given to
clinging to suitable substrates, and by lifting and shaking the lures
over a net, the young prawns are easily taken. They may also be
caught from canoes with hand-nets. During the peak season, as many
as 1 000 young prawns per hour's work can be taken. Larvae are easily
distinguished by a streak of dark-brown pigment running through their
transparent bodies.
When the young fish or prawns are caught, they are bought by
dealers who resell them either to the farmers or to specialist fry cultwists. I n the hands of the ordinary fish-farmer the mortality among
fish fry can be very high. Schuster (1952) says that a 30% survival of
planted fry is a usual result in Java. Such low survival rates make the
surviving fry costly and better care will clearly result in cheaper
stocking material. For example, Djainsastro (1956) found that a very
thorough screening of the water admitted to the fry-ponds, thus
excluding predators, much improved the rate of survival of Chanos
fry. Pillay (1966) says that little care is usually taken of grey mullet
fry because they are so cheap, and the losses can be very high indeed.
But Yashouv (1966) shows that when the very young mullet fry (151 8 m m long) are caught in the mouths of streams on the coast of
Israel, and stored in small ponds where they have care and are fed to
maintain their strength and growth, the mortality over so long a period
as 4 months could be only 20-30%.
A very sensible arrangement which seems to be increasing in the
principal Chanos-growing countries is for certain dealers to specialize
in the care and rearing of the tiny fry to strong fingerlings. Such
specialists can reduce losses to 20-40%. With such a supply of well
grown fingerlings available, progressive fish culturists can raise two or
even four crops of fish in a year. Further, such a reserve of fingerlings
is some insurance against a failure of the fry fishery (Mane et al., 1952).
C. Care and rearing of fry
1. Chanos
These fry, when first obtained, are kept for a longer or shorter time
in special very small ponds (with the delightful name of " baby boxes "),
159
Philippines, where the valuable " Sugpo ) ) or Penaeus monodon (Fbr.)
is cultivated in ponds with Chanos or by itself (Caces-Borja and Rasalan,
1967).
As with the young of the other penaeids used in farming, the creeks,
lagoons and other shallow areas are the places where fishing for young
takes place. Fish-lures are used, which take the usual form of bunches
of grass tied along a rope which is moored in shallow water. One man
may operate many of these ropes. The " sugpo " young are given to
clinging to suitable substrates, and by lifting and shaking the lures
over a net, the young prawns are easily taken. They may also be
caught from canoes with hand-nets. During the peak season, as many
as 1 000 young prawns per hour's work can be taken. Larvae are easily
distinguished by a streak of dark-brown pigment running through their
transparent bodies.
When the young fish or prawns are caught, they are bought by
dealers who resell them either to the farmers or to specialist fry cultwists. I n the hands of the ordinary fish-farmer the mortality among
fish fry can be very high. Schuster (1952) says that a 30% survival of
planted fry is a usual result in Java. Such low survival rates make the
surviving fry costly and better care will clearly result in cheaper
stocking material. For example, Djainsastro (1956) found that a very
thorough screening of the water admitted to the fry-ponds, thus
excluding predators, much improved the rate of survival of Chanos
fry. Pillay (1966) says that little care is usually taken of grey mullet
fry because they are so cheap, and the losses can be very high indeed.
But Yashouv (1966) shows that when the very young mullet fry (151 8 m m long) are caught in the mouths of streams on the coast of
Israel, and stored in small ponds where they have care and are fed to
maintain their strength and growth, the mortality over so long a period
as 4 months could be only 20-30%.
A very sensible arrangement which seems to be increasing in the
principal Chanos-growing countries is for certain dealers to specialize
in the care and rearing of the tiny fry to strong fingerlings. Such
specialists can reduce losses to 20-40%. With such a supply of well
grown fingerlings available, progressive fish culturists can raise two or
even four crops of fish in a year. Further, such a reserve of fingerlings
is some insurance against a failure of the fry fishery (Mane et al., 1952).
C. Care and rearing of fry
1. Chanos
These fry, when first obtained, are kept for a longer or shorter time
in special very small ponds (with the delightful name of " baby boxes "),