W"￣Bu11. Toyama

Pref， Res. lnst， N0,12、 43−46（2000）

Ａｂａｌｏｎｅｏｆ ａｓｅａｗａｔｅｒ

ｍｏｕｔｈｆｕｌ

ｐｕｍｐｅｄｓｉｚｅ ｒｅａｒｅｄ

ｆｒｏｍｔｈｅ(Acceptedon

ｄｅｅｐMarchDaisukeｗｉｔｈａｔｔａｃｈｅｄ ｄｉａｔｏｍｓｉｎ

ｗａｔｅｒｏｆ Ｔｏｙａｍａ

Ｂａｙ20， 2000)

FUJITA*oAbstract

Juvenileshells（37 andhannai， werein she11 1ength）of

cultured in outdoor

utilization of
Sea

47 mm

deep‑sea

the culture， heatedfromdeep‑sea

Attached

aof

the newly

excreted

too coldshallowmouthfulwaterminimumshells was

deep‑seaof waterfromaheat‑exchanger（opeundergroundfreshwater

encrusting

green

commercial
anymasscomparativelyof ToyamaBaysize （60mmmortality.

smoothinmicro‑algae，び7リeZZαZeπfed to abalone.AfterinSL），what

0utersurface

becauseThis is the first demonstrationwaterBay.lnsalmon， C玩cor八ync垣zs masoび）wasused.

size without

temperature.

seawaterendemictoin Toyamawater of 3（C andin the tank （andreachedis calledwaterof 321 m

after accidental invasion）wereten months， the abalone

use

masu

blooming

blooming

ambient

deep‑seaculturing

diatomsa depthof multiple/cascade

nutrient‑richwater （12℃）consisting

betweenof 17℃fortanks in the course

water（cold，cleanof Japan）pumped

the abalone， yvordc心sぷscMs

ofofconstantshowingthe

aquaculture

oftemperate

species of shellfish.

Key words; abalone， aquaculture， deep‑sea water，heat exchanger，
0ylcor八yncたMs
masoび，yVordo￡fsぷscgs/1a7777
ln ToyamamPrefecture， deep‑sea

off Toyama

has

been

Prefectura1

water （DSW）has

its coldness（ca.3℃after

pumping

to the surface）as

usedof cold

waterbroodstocksfor heat‑exchangeascoon‑stripedcharacteristicof DSW

duringits fresh

shrimp，?αnd｢乙zsof multiple/cascade

the extensive

coverof attachedduringwaterlife. lt has

a depthNamerikawa

Cityof321

since1995.Becauseof

well as cleanliness，DSW

such

its seawater
also

from

as Masu
life andbeen

usedsalmon，C屠corたync八Ｍｓ
as a coldsource

to maintaindeep/1yps泌o缶s.Anotherdeep‑sea
diatoms

specieswater

is its richness in nutrients suchour programinup

lnstituteas ambient

such

pumpedResearch

to keep

Fisheries

been｢waterfoundthat it fulfills one of the objectivesin

utilization. Thein outdoor

DSWauthor

paidtanks， and*1）Toyama Prefectura1 Fisheries Research lnstitute，364 Takatsuka， Namerikawa，Toyama

attentionto

foundthatPref.，936‑8536）

seawater

44

富山県水産試験場研究報告第12号 (2000)

juv
enileshellso
fa northernform of abalone，Nor
doti
sdiscus hαnnαi，grew well up toize'，60mm，ju
stbyonlyfeedingon them.
what wecall a mouthfuls
Inthecultureo
f abalone，DSW (HEDSW，12C) heat‑exchanged with underground0freshwater (17C) was used，because it was nottoocold andavailablefrom the cu1tur
e0system for brood‑stocking of masu salmon. HEDSW was poured into an outdoor tank(0.
9X1.8XO.
7m) ;
:
tta r
ateo
f24l
iter
/mi
nandke
p
twit
houti
nt
r
odu
ci
n
gany animals fora month. In a few weeks，attached diatoms，whichderiv
edfrom DSW (probably sinking
from shallow water) v
isibl
y covered thewalls and bottom ofthetank. The diatomcommunity was comprisedofbothsolitar
y andcolon
ialspecies(20speciesof13genera)
，
inclu
din
g Achnαntheslongipes which brought better growth ofN.discus hαnn
αthankelpLαmmαnαjαp OnLCα(Takami etα.
l1996). Diatom floraint
he tank i
sdescribe
dintal.2000). From June，1999，however，small encr
ustinggreendetailelsewhere (Suzuki ealgae Ulvell
αlens has beendominant and covereda
lloft
hei
nne
rsur
face
soft
hetank.
The algae was probablyderivedfrom short‑term‑deposite
dintertidalsnails andadaptedto abalone grazingtogetherw
ithsessile diatomssuchas Cocconeisspp.
Abalone culture wasstartedw
ith10juv
enileshells(37mminshelllength(SL)) onJuly
1，1
9
98. Then 50 largers
hells(47mminSL) were added on October9，1998，togetherw
ithtwo casesof corrugated plates (made ofpolyv
inylchloride，30X30cmX10 sheets/case)toi
ncr
easethe diatom‑covered area. Theseabalonesweret
heshellsproducedi
nToyamaPr
efecturalSea FarmingCenteri
nautumno
f1996. The watertemperaturewasbetwe
en9o
C and 12C all through the year.The tank was covered with transparent board0(made ofacrylicresin) as a snow shelter during w
inter，and any accumulated snow
was removed once w
ith
in a few days.
After cultu
rin
gfor one month，l
i
gh
t
‑gr
e
e
nco
lor
eds
he
l
l was excr
ete
datt
h
e marginheir growth. Grazing marks extended gradually andoft
he abalone，which showed t
covered all over the inner sur
facesofthetank. Abalones moved around activ
elywithelongated tentacle
sparticularlyint
he morning and ev
ening. The activ
e movement
suggestedt
hat they were quitehealthy.
Afterten months，some ofor
iginal10shells reached 60mm(Fig.
1).The outersur
faceivingi
nconstant water temperature conditionof HEDSW，wasoftheshell，formed byl
verysmooth. Surv
ivalratFujita:Abalonerearedindeep‑seawater

4
5

ぷ:'>.
.

Fig.l Abalone ofa mouthfuls
ize，Nordoti
sdiscus hαnnαi，reared with attacheddiatoms in deep‑seawaterpumped from ToyamaBay.

hαnnαi，by coolingthetoo warm' pumped shallow waterwithDSW.Fukamietal.(1997)

culturedanattacheds
peciesofthediatomNitzschi
α，byusingc
uthoses (asabioreactor)
wit
hflowingDSWincylinde
rtanksandrearedj
uv
enileshells(25mminSL) ofN.gigα
ηteα(αsHαlioti
ssieboldii) by allowing them tofeed on them. Theyachieved growth of 1mminSL after one month. Nabeshima etal.(1999) reported on a land‑based tank cultureofN.gigαnt
eαby feedingkelp culturedi
nthe wasteo
ffish‑cultur
ewater. The presentrepor
t demonstrates thepossibilityofproducing abaloneo
fa mlDlmum commercials
izeonlyusing DSW and attacheddiatoms blooming in DSW.
Stock enhancement of abalone isattractiv
e because ofits high price such thattenso
fthousands ofjuvenileshells have been releasedin many areas of Toyama Bay since
1979(Fujita1998).However，therateo
freleasedshells(Fujita& Shozen 1999) and therateo
frecapture (Fujita& Seto2000) have beenquite low in Toyama Bay. Therefore，land‑based culturein DSW is an alternativ
e approach toincr
easin
g abalone in Toyama
Prefecture.Particu
larly，HEDSW may be a good way t
o reduce thecost (e.
g.，forwarming，feeding andkeepinghealth) amongDSWandthei
rv
ar
iou
sw
ast
es.Produ
ctiv
ityo
fattacheddiatoms，optimum abalonedensityi
ntanksasw
ellascombinationwithotherfood(e.
g.，kelp culturedin multiple/cascade culturesystem) willbet
he next targetsofthisstudy.

富山県水産試験場研究報告46第12号（2000）

富山湾深層水中に繁茂する付着珪藻を用いて育成した一ロアワビ
富山湾の水深321mから汲み上げている深層木（低温，清浄で栄養塩に富む日本海固有木）の多目的／多段利用の一段階として，屋外水槽でエゾアワビ（殼長37mmと47㎜）の養殖を試みた。本養殖では，サクラマス飼育用の熱交換器（３℃の深層木と17（Cの地下水の間で熱交換）から排出される加湿深雁木を用い，水槽内で繁茂した付着珪藻をアワビに摂餌させた。アワビは，10ヵ月後でも目立ったへい死がなく，一目アワビと呼ばれる最小流通サイズ（殼長60mm）に成長した。
飼育水が恒温であるため，新たに分泌された殼の外表面は比較的滑らかであった。これは，「冷たすぎる」深層木（日本海固有木）を温惰性浅海種の周年養殖に活用した最初の事例である。

Ｒｅｆｅｒｅｎｃｅｓ

Fujita，D.1998.Awabi.（Ed.Toyamano sakanatachi
Fujita D. andwa ma

p.40‑41.Katsura

City，Toyama

Prefedure.

Pref. Fish.Res.lnst.，12: 13‑18.

K. Shozen

1999. Toyama‑kentobu（Kurobe‑shi，Nyuuzen‑machi，Asahi‑M.Yamaguchi

andM. Taniguchi

benthicfood diatom

1998. Continuous

y此zsc厄a sp. andseawater.J.Mar.Biotech，6:
Hamai，M.1996.Ezo‑awabi

abalone召andsimultaneous｢泌瓦ss泌&｢dacultivation of皿by㎜

using deep㎜237‑240.

shubyosoki seisan shiken. Ann.Rep.Toyama

Pref. Fish.

Nabeshima，H.，M，Watanabe，T.Yamamoto，M.Hiraoka

1999. Kaiyo

sorui baiyo to haisui no yuko riyo.P.38‑39.Kaiyo

Shinso‑suishinso‑sui ni yoru
99SagaTaikai Kouen

Youshishu，JADOWA.

l一‑ESiii.1Σ二̲̲

andwater of Toyama
Takami，H.，T.Kawamura

皿四Res.lnst.（1995），109‑110.

Suzuki，H.，T.Nagmumomachi）eng

皿

Fukami，K｡，A.Kawai，M.Asada，M.0kabe，T.Hotta，T.Moriyama，S.Doi，T.Nishijima，

thegrowthwan

Shobo.Toyama.

Y. Seto 2000. Notes on released abalone in uozu

Bu11.Toyama
Fujita，D.and

Prefectura1 Fishieries Research lnstitute）Toyama‑and

D. Fujita 2000. AttachedBay. Bu11.Toyama
Y. Yamashita

diatoms

bloomedin pumped‑up

Pref. Fish.Res.lnst.，12:

33‑42.

1996. Dietary value of benthic diatoms forof juvenile abalone. Suisanzoshoku，44:

211‑216.

迦Ｓ蓉

deep‑se紅玉]E≧⊃JIL＿