Farming the SM
59
transmitting ‘alarm’ signals could keep sh penncd in the marine
eld. Even electrical barriers have been considered;
-
,
.
One of the most successful 'ventures in mariné tfarming*so fat-is
the rearing of the Japanese prawn Penzæus japonica. The key gure;
in this work is Dr Motosaku Fujinaga who until 1954 Was Director
of the Research Bureau …of the Japanese Fisheries Agency. Dr
Fujinaga has devised methods for hatehing reggs obtained
‘berried’ female prawns brought in by shermen.0ne female may
lay anything between half a million and a million eggs. Justlike the
British sh breeders, he also had to develop
masses of food for the larvae——whicheat adia—t0m called Skeletonema
.
costaz‘um. After feeding on this microscopic plant; the growing“
.
prawns move on to graze on animals such ascopepods and=brine
shrimps and, when two centimetres long, theprawnis ready—“tube
put out to past—ure. Because the prawns do n0t grow înuchmore than
eight or nine inches long, they do not Îrequire the extensive ‘»elds’f
envisaged for the plaice. The largest sea—water pond usedfottheir -
cultivation is 100,000 square metres (about 24
metre yields two to three mature animals—about 9,000—pràwnsçper
acre——and each year over 100 tons of prawns are sent to the Tokyo
market. Before being despatched the prawris tare dippedinbold
water to slow down their metabolism so'thatathe “small amounts of
water trapped- in their gills su“ppliés sufcith Oxygen to ensurethat
they reach the market alive—an essential
arcady
sale inJapan.
f
—
”
‘
…
*
The suCcess of this Japanese
largeÏly0ntwo Criteria:
s0und experimental work on the best JmethodS àOf1farming>g and
favourable marketing c0nfditionéz And*0f
high
price is the decisive factor. Even during
ca‘ùght pratwñs are plentiful; prices
ümèä-higêham
the United States or». the Unitä‘:dKingd0m; Out
increases still
sometimes teaching
375.) =_:p‘e:î
pound. Such prices 'more £:than … cover “éthè Ï‘Ïadditional”eärpensc 1—1fo
Cultivation"and give the 11nar}iñe "farmer with;hié
an Opportunity
the markeusituàtiorrà N oçsd0utiz Rif, similar
conditions , prevailed‘ for *plaice
mthe British ‘fmaIket3{
present sh farming effort would be":g'teatlyjaccéleràtèd. Andtimes
could change;1As
protein, the size of
not the =Catches, ‘will_Ëfall.
éhâWill only be suitable for7ite"rthsu0h as *5‘sh
59
transmitting ‘alarm’ signals could keep sh penncd in the marine
eld. Even electrical barriers have been considered;
-
,
.
One of the most successful 'ventures in mariné tfarming*so fat-is
the rearing of the Japanese prawn Penzæus japonica. The key gure;
in this work is Dr Motosaku Fujinaga who until 1954 Was Director
of the Research Bureau …of the Japanese Fisheries Agency. Dr
Fujinaga has devised methods for hatehing reggs obtained
‘berried’ female prawns brought in by shermen.0ne female may
lay anything between half a million and a million eggs. Justlike the
British sh breeders, he also had to develop
masses of food for the larvae——whicheat adia—t0m called Skeletonema
.
costaz‘um. After feeding on this microscopic plant; the growing“
.
prawns move on to graze on animals such ascopepods and=brine
shrimps and, when two centimetres long, theprawnis ready—“tube
put out to past—ure. Because the prawns do n0t grow înuchmore than
eight or nine inches long, they do not Îrequire the extensive ‘»elds’f
envisaged for the plaice. The largest sea—water pond usedfottheir -
cultivation is 100,000 square metres (about 24
metre yields two to three mature animals—about 9,000—pràwnsçper
acre——and each year over 100 tons of prawns are sent to the Tokyo
market. Before being despatched the prawris tare dippedinbold
water to slow down their metabolism so'thatathe “small amounts of
water trapped- in their gills su“ppliés sufcith Oxygen to ensurethat
they reach the market alive—an essential
arcady
sale inJapan.
f
—
”
‘
…
*
The suCcess of this Japanese
largeÏly0ntwo Criteria:
s0und experimental work on the best JmethodS àOf1farming>g and
favourable marketing c0nfditionéz And*0f
high
price is the decisive factor. Even during
ca‘ùght pratwñs are plentiful; prices
ümèä-higêham
the United States or». the Unitä‘:dKingd0m; Out
increases still
sometimes teaching
375.) =_:p‘e:î
pound. Such prices 'more £:than … cover “éthè Ï‘Ïadditional”eärpensc 1—1fo
Cultivation"and give the 11nar}iñe "farmer with;hié
an Opportunity
the markeusituàtiorrà N oçsd0utiz Rif, similar
conditions , prevailed‘ for *plaice
mthe British ‘fmaIket3{
present sh farming effort would be":g'teatlyjaccéleràtèd. Andtimes
could change;1As
protein, the size of
not the =Catches, ‘will_Ëfall.
éhâWill only be suitable for7ite"rthsu0h as *5‘sh