158
C. F. HICKLING
I n English estuaries, grey mullet fry appear abundantly in the
summer months from June and July to October (Hickling, 1970). At
first, they tend to shelter among weeds, but later they move about
with the tide, and tend to collect where a stream enters the sea. It is
not difficult to take them in large numbers but there is no demand for
them.
Long-handled scoop nets are used for the capture of elvers. As the
tide rises, for example in the River Severn below Gloucester, the elvers
migrate upstream in dense shoals close t o the bank. They are easily
scooped out into buckets.
The fry of the yellowtail, Seriola quinqueradiata, shelter among
masses of floating seaweed and are caught by scoop nets or by encircling the floating masses of seaweed with small seines (Anraku and
Azeta, 1966). The seaweed also harbours arich population of crustaceans
but the young yellowtail feed exclusively on zooplankton until they
are 2.5 em in length, and after a length of 13 cm, exclusively on fish.
The larvae of prawns are wholly caught in the sluices of the ponds
where they will be raised. They are carried in with the water when
the ponds are filled. Both Hall (1962) and Schuster (1952) give advice
as t o how t o increase the intake of young prawn. Since it is inconceivable that a pond might be overstocked with prawns, everything
possible is done to bring in as many larvae as possible. Insteadof relying
on chance that good quantities of prawn fry will enter when the sluice
is opened at high tide, Schuster advises that a head of water of about
one foot should be allowed t o build up outside the pond. Then the
opening of the sluice will result in a strong inrush of water which will
carry in the prawn larvae, which are poor swimmers. A similar method
is used to secure a good entry of young prawns into the paddy fields of
south India. Hall (1962) makes a number of points, for example, that as
many of the sluice gates of the pond as possible should be opened at
high tide, especially during the months of March, June and November,
when the prawn young are most plentiful in the Singapore area ; and
that this should be done even if it means having to release some water
later. As the young prawns, unlike the adults, are as abundant in the
water by day as by night, every chance should be taken, and where a
partial opening to the sluices is needed, this should be a t the bottom,
rather than a t the top, since post-larvae, which might be settling
outside the ponds, would then be swept in. Similarly, when taking the
young of fish and prawns into the Indian bheris, Pillay ( 1 954) says that
emergency extra gaps may be cut in the embankments to take in as
many as possible.
There appears t o be a specialist fishery for young prawn only in the
C. F. HICKLING
I n English estuaries, grey mullet fry appear abundantly in the
summer months from June and July to October (Hickling, 1970). At
first, they tend to shelter among weeds, but later they move about
with the tide, and tend to collect where a stream enters the sea. It is
not difficult to take them in large numbers but there is no demand for
them.
Long-handled scoop nets are used for the capture of elvers. As the
tide rises, for example in the River Severn below Gloucester, the elvers
migrate upstream in dense shoals close t o the bank. They are easily
scooped out into buckets.
The fry of the yellowtail, Seriola quinqueradiata, shelter among
masses of floating seaweed and are caught by scoop nets or by encircling the floating masses of seaweed with small seines (Anraku and
Azeta, 1966). The seaweed also harbours arich population of crustaceans
but the young yellowtail feed exclusively on zooplankton until they
are 2.5 em in length, and after a length of 13 cm, exclusively on fish.
The larvae of prawns are wholly caught in the sluices of the ponds
where they will be raised. They are carried in with the water when
the ponds are filled. Both Hall (1962) and Schuster (1952) give advice
as t o how t o increase the intake of young prawn. Since it is inconceivable that a pond might be overstocked with prawns, everything
possible is done to bring in as many larvae as possible. Insteadof relying
on chance that good quantities of prawn fry will enter when the sluice
is opened at high tide, Schuster advises that a head of water of about
one foot should be allowed t o build up outside the pond. Then the
opening of the sluice will result in a strong inrush of water which will
carry in the prawn larvae, which are poor swimmers. A similar method
is used to secure a good entry of young prawns into the paddy fields of
south India. Hall (1962) makes a number of points, for example, that as
many of the sluice gates of the pond as possible should be opened at
high tide, especially during the months of March, June and November,
when the prawn young are most plentiful in the Singapore area ; and
that this should be done even if it means having to release some water
later. As the young prawns, unlike the adults, are as abundant in the
water by day as by night, every chance should be taken, and where a
partial opening to the sluices is needed, this should be a t the bottom,
rather than a t the top, since post-larvae, which might be settling
outside the ponds, would then be swept in. Similarly, when taking the
young of fish and prawns into the Indian bheris, Pillay ( 1 954) says that
emergency extra gaps may be cut in the embankments to take in as
many as possible.
There appears t o be a specialist fishery for young prawn only in the