Milkfish broodstock technology of SEAFDEC/AQD

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Southeast Asian Fisheries Development Center Aquaculture Department

SEAFDEC/AQD Institutional Repository http://repository.seafdec.org.ph

Journals/Magazines Aqua Farm News

1993

Milkfish broodstock technology of SEAFDEC/AQD

Aquaculture Department, Southeast Asian Fisheries Development Center

Southeast Asian Fisheries Development Center, Aquaculture Department (1993). Milkfish broodstock technology of SEAFDEC/AQD. Aqua Farm News, 11(2), 3-6, 8.

http://hdl.handle.net/10862/2553

Downloaded from http://repository.seafdec.org.ph, SEAFDEC/AQD's Institutional Repository

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Milkfish broodstock technology of SEAFDEC/AQD

S E A F D E C / A Q D s c ie n t is t s h a v e b e e n w o r k in g o n m ilk fis h b r e e d in g s in c e th e la te 19 7 0 s . F o llo w in g s u c c e s s fu l b r e e d in g o f m ilk fis h in c a p tiv ity , S E A F D E C /A Q D p u b lis h e d in 1 9 8 4 a g u id e fo r th e e s ta b lis h m e n t a n d m a in te n a n c e o f m ilk fis h b r o o d s to c k .

T h is g u id e w a s u p d a te d in la te 1 9 9 2 , n o w c o n s id e r in g s e v e r a l d e v e lo p m e n ts - im p r o v e d e g g c o lle c t io n t e c h n iq u e s , a s ta n d a r d e g g t r a n s p o rt p r o c e d u r e , th e s p o n ta n e o u s m a tu r a tio n a n d s p a w n in g o f m ilk fis h in c o n c r e t e ta n k s , a n d a n im p r o v e d h a tc h e r y te c h n o lo g y .

S E A F D E C /A Q D 's b r o o d s t o c k m a n a g e m e n t te c h n iq u e s a r e d e s c r ib e d b e lo w .

So u rces of b ro o d sto ck

M ilk fis h ju v e n ile s ( w e ig h t, 2 5 0 - 3 5 0 g ) c a n b e o b ta in e d f r o m b r a c k is h w a t e r p o n d s a n d fis h p e n s w h e r e th e y h a v e b e e n c u ltu r e d f o r a fe w m o n th s to a y e a r .

M ilk fis h ju v e n ile s a re tr a n s p o r te d t o th e b r o o d s to c k c a g e s o r ta n k s in a flo a tin g fis h c a g e o r in a 1 .5 - m d ia . c a n v a s ta n k w it h 0 .5 - m d e e p w a t e r w ith a e r a tio n . T h e c a n v a s ta n k m a y b e s u s p e n d e d a t th e b a c k o f a p ic k - u p tr u c k o r p la c e d in th e h u ll o f a p u m p b o a t.

F o r a s ta r t, a b o u t 1 0 0 ju v e n ile s c a n b e

s to c k e d in a 1 0 - m d ia . c a g e o r ta n k . A f t e r t h r e e y e a r s , h a lf o f th is s to c k c a n b e tr a n s f e r r e d to a n o th e r 1 0 -m d ia . c a g e o r ta n k u n til m a t u r ity is a tta in e d . A t th is tim e , a n o t h e r 1 0 0 ju v e n ile s c a n b e s to c k e d in a n o th e r 1 0 - m d ia . c a g e o r ta n k .

H olding facilities fo r b ro o d s to c k

F lo a tin g c a g e s m u s t b e lo c a te d in a w e ll p r o te c te d a r e a w it h m in im u m w a v e a c tio n e v e n u n d e r a d v e r s e w e a t h e r c o n d itio n s . T h e s ite s h o u ld h a v e g o o d w a te r c ir c u la tio n , s a n d y - m u d d y s u b s tr a te , a n d a m in im u m w a t e r d e p th o f 5 m a t th e lo w e s t tid e .

M ilk fis h a re th e n r e a r e d in 6 - o r 1 0 - m d ia . x 3 - m d e e p flo a tin g n e t c a g e s . C o r a lo n n e t (m e s h s iz e , 5 .7 c m ; s iz e o f t w in e , 2 1 0 d /6 0 ) p r e v io u s ly tr e a te d w it h c o a l t a r is u s e d a s c a g e n e ttin g . A n e t a llo w a n c e o f a b o u t 3 0 % is p r o v id e d to h a v e g o o d w a t e r e x c h a n g e . T h e t o p is c o v e r e d w ith a s im ila r n e t s iz e to p r e v e n t fis h fr o m ju m p in g o u t. T h e b o tt o m is c o v e r e d w ith fin e k n o tle s s n e t ( m e s h s iz e , 3 m m ) to r e ta in s in k in g fo o d . T h e c a g e s a r e s u p p o r t e d b y flo a ts w h ic h a re e ith e r c y lin d r ic a l s ty r o fo a m o r e m p t y p la s tic d r u m s ( 0 . 6 - m d ia . x 1 m ) f itt e d to t h e c a g e fr a m e , b u t a llo w in g f o r e a s y r o t a tio n t o c h e c k fo u lin g . C a n v a s c lo th o r fin e n e t ( m e s h s iz e , 1

In the book-launching ceremony of the manual on Management of Milkfish Brood

stock held March 4 at Iloilo City, SEAFDEC/AQD Chief Efren Ed.

Flores (far left) noted that the manual's mass reprinting will be funded by the Fisheries Sector Program of the Department of Agriculture. This is significant in view of the Philippine

Government's move to privatize the NBBP stations.

Senior author Arnil Emata (far right) hands over a

complimentary copy to the representative of the private sector, Dr. Salvador Dolar. Looking on is Dr. Cesar Villegas, Head of AQD's Training and Information Division.

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m m ) is w ra p p e d a ro u n d th e flo a ts fo r p ro te c tio n a g a in s t fo u lin g o rg a n is m s .

C a g e m a in te n a n c e is d o n e re g u la rly a n d in v o lv e s :

1. D a ily in s p e c tio n to d e te c t te a rs in th e n e t

tin g a n d to re m o v e d e b ris a n d fo u lin g o r

g a n is m s ;

2. P e rio d ic ro ta tio n o f c y lin d ric a l flo a ts , re p a in tin g o f w o o d e n fra m e o r g a lv a n iz e d iro n (G I) p ip e w ith c o a l ta r; a nd

3 . C h a n g in g o f n e ts e v e ry 2 m o n th s o r as n e e d e d to p ro te c t it fro m fo u lin g o rg a n is m s .

F o u le d n e ts a re s u n -d rie d , c le a n e d , a n d re p a ire d . W h e n th e s p a w n in g s e a s o n sta rts , n e ts a re le ft a lo n e so th a t fis h a re n o t d is tu rb e d . S tre s s re s u lts in g o n a d a l re g re s s io n a n d d e la y o f s p a w n in g .

L a n d -b a s e d c o n c re te ta n k s m e a s u rin g 8 m x 8 m x 2 -m d e e p a re s u ffic ie n t fo r m ilk fis h b ro o d s to c k . A d o u b le p ip e d ra in a g e is in s ta lle d to a llo w w a t e r to flo w o u t fro m th e b o tto m . W a te r in le ts a n d a e ra tio n lin e s a re lo c a te d at th e to p . A

b la c k s a c k c lo th c o v e rs th e ta n k to m in im iz e e x c e s s iv e g ro w th o f a lg a e .

D a ily w a te r in flo w s h o u ld b e a d ju s te d to c h a n g e a t le a s t 5 0 % o f th e w a te r v o lu m e . T h e s id e s a n d b o tto m o f th e ta n k s h o u ld b e b ru s h e d m o n th ly . T h e ta n k c a n b e d ra in e d to a t le a s t a fo o t in d e p th fo r b ru s h in g . D u rin g th e s p a w n in g s e a s o n , w a te r in flo w s h o u ld b e in c re a s e d so th a t b ru s h in g a n d d ra in in g c a n b e m in im iz e d .

In b o th ta n k s a n d c a g e s , o p tim u m s to c k ing d e n s ity s h o u ld n o t b e m o re th a n 1 k g /m 3.

Feeding

T w o - to fo u r-y r o ld m ilk fis h a re fe d tw ic e d a ily w ith c o m m e rc ia l fis h p e lle ts (2 4 % p ro te in ) at 3 % o f th e ir to ta l b o d y w e ig h t. U p o n n e a rin g m a tu ra tio n b y th e fo u rth y e a r, fis h a re fe d tw ic e d a ily w ith c o m m e rc ia l s h rim p p e lle ts w ith 3 6- 4 2 % p ro te in a n d 6 -8 % lipid. D a ily fe e d in g ra tio n is in c re a s e d to 4 % o f to ta l b o d y w e ig h t. F e e d s a re b ro a d c a s t to th e fis h b y h a n d .

The Igang Marine Station o r IMS is one of SEAFDEC/AQD's three research stations, and where breeding technology for fishes — milkfish, grouper, and sea bass — are developed. In 1982, milkfish was spawned for the first time in captivity by the team headed by endocrinologist Dr. Flor Lacanilao (inset).

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D eterm in atio n o f g o n ad al d evelo p m en t

F ro m th e fifth y e a r a n d th e re a fte r, th e fis h a re s a m p le d in M a rc h a n d in N o v e m b e r to d e te rm in e th e s ta g e o f g o n a d a l d e v e lo p m e n t a n d to d e te rm in e th e s e x u a l c o m p o s itio n o f th e s to c k . A s e x ra tio o f o n e fe m a le to o n e m a le o r tw o fe m a le s to o n e m a le is a d e q u a te fo r e g g p ro d u c tio n . U n s e x e d fis h c a n be k e p t in a s e p a ra te c a g e o r ta n k to b e s e x e d la te r in th e s e a s o n o r in th e n e x t s e a s o n . E x c e s s m a le s c a n b e s a c rific e d , o r re le a s e d to th e s e a in o rd e r to s a v e o n fe e d s . (S e e s e p a ra te s e c tio n o n re p ro d u c tiv e b io lo g y , p .7 .)

T h e s ta g e o f g o n a d a l d e v e lo p m e n t c a n be m o n ito re d th ro u g h th e c a n n u la tio n b io p s y te c h n iq u e . T o fa c ilita te th is , th e n e ts o f th e flo a t

ing c a g e s a re lifte d g ra d u a lly , o r th e c o n c re te ta n k s d ra in e d . D is tu rb a n c e m u s t be m in im iz e d to p re v e n t a n y p h y s ic a l in ju ry to th e fis h .

F is h a re in d iv id u a lly s c o o p e d o u t a nd th e n p la c e d in a 4 0 0 -l fib e rg la s s ta n k c o n ta in in g 2 0 0 l s e a w a te r a n d 2 0 0 p p m (4 0 m l) 2 -p h e - n o x y e th a n o l (a n a n e s th e tic ). T h e a n e s th e tic s h o u ld b e m ix e d w ith a little w a te r b e fo re it is p la c e d in th e ta n k . A n e s th e tiz e d fis h a re c h a ra c te riz e d b y lo s s o f b a la n c e (v e n tra l s id e u p ), im m o b ility , a n d ra p id a n d s h a llo w o p e rc u la r m o v e m e n t.

F is h a re w e ig h e d a n d th e n tra n s fe rre d to a s h a llo w tro u g h (0 .5 m x 1 .5 m x 0 .1 5 -m d e e p ) c o n ta in in g 1 0 0 p p m 2 -p h e n o x y e th a n o l to k e e p th e fis h a n e s th e tiz e d .

C a n n u la tio n b io p s y is d o n e in th e fo llo w ing m a n n e r:

In th e w o o d e n tro u g h , th e fis h is la id o n its d o rs a l s id e . T o d e te rm in e th e p re s e n c e o f w h ite v is c o u s m ilt, its v e n tra l s id e is g e n tly p re s s e d , s ta rtin g fro m h a lfw a y o f th e a b d o m e n to th e a n a l re g io n .

If no m ilt o o z e s o u t, a c a n n u la (o r p o ly e th y le n e tu b in g w ith a 0 .8 6 m m in n e r dia . a n d a 1 .5 2 m m o u te r d ia .) is in s e rte d in to th e g e n ita l p o re . D iffic u lty in in s e rtin g th e c a n n u la th ro u g h th e g e n ita l p o re m a y be e n c o u n te re d a m o n g b ro o d s to c k u n d e rg o in g th e ir firs t m a tu ra tio n a n d a m o n g fis h e x a m in e d e a rly in th e b re e d in g s e a s o n . T h e fre e e n d o f th e c a n n u la is h e ld in th e m o u th . T h e c a n n u la is a s p ira te d w h ile s lo w ly b e in g w ith d ra w n fro m th e fis h .

T h e c a n n u la is im m e d ia te ly in s p e c te d . A m ilk y w h itis h s u b s ta n c e in d ic a te s a m a tu rin g o r m a tu re m a le . S p h e ric a l y o lk y o o c y te s a p p e a r

tra n s lu c e n t to o p a q u e (q u ite d is tin c t fro m fa tty tis s u e w h ic h lin e s th e a b d o m in a l w a ll). C a n n u la te d g o n a d a l tis s u e a re th e n b lo w n in to a s m a ll c o v e re d tu b e a n d 5 % fo rm a lin s o lu tio n is a d d e d to p re s e rv e o o c y te s fo r e x a m in a tio n a n d m e a s u re m e n t.

A fe w o o c y te s a re p ip e tte d fro m th e tu b e a n d p la c e d o n a g la s s s lid e . T h e d ia m e te r o f 1 0 -3 0 o o c y te s a re m e a s u re d u n d e r a m ic ro s c o p e p ro v id e d w ith a n o c u la r ru le . O o c y te s iz e in d ic a te s d e g re e o f s e x u a l m a tu rity . F e m a le s w ith an o o c y te d ia m e te r e q u a l to o r g re a te r th a n 0 .6 7 m m a re c o n s id e re d n e a r fin a l m a tu ra tio n a n d s p a w n in g . A s re v e a le d b y in d u c e d s p a w n ing s tu d ie s , th o s e w ith o o c y te d ia m e te r le s s th a n 0 .6 7 m m a re m a tu rin g o r e a rly m a tu re d .

F o llo w in g s a m p lin g , th e fis h a re p la c e d in a re c o v e ry ta n k w ith flo w -th ro u g h w a te r a n d a e ra tio n . F ish m u s t b e fu lly re c o v e re d a n d s w im m in g n o rm a lly b e fo re th e y a re re tu rn e d to th e m a in ta n k o r c a g e . R e c o v e ry fro m a n e s th e s ia in fre s h s e a w a te r c a n b e fa c ilita te d b y h o ld in g th e fis h in th e c a u d a l p e d u n c le a n d s w in g in g it b a c k a n d fo rth u n til o p e rc u la r m o v e m e n t b e c o m e s n o rm a l a n d e q u ilib riu m is re g a in e d .

Spaw ning an d egg c o lle c tio n

M a tu re m ilk fis h a re le ft to s p a w n n a tu ra lly in c a g e s o r ta n k s .

W h e n s p a w n in g is e x p e c te d , th e c a g e is p re p a re d fo r th e c o lle c tio n o f s p a w n e d e g g s . A m a n u a lly o p e ra te d e g g c o lle c to r is in s ta lle d o v e r th e flo a tin g c a g e . T h e e g g c o lle c to r is c o n s tru c te d o f tw o p a ra lle l G I p ip e s (0 .7 5 -in . d ia .) c o n n e c te d to a c e n tra l s h a ft s u p p o rte d b y a w o o d e n tru s s fra m e . A fin e n e t (m e s h s iz e , 0 .6 - 0 .8 m m ) is a tta c h e d to th e p a ra lle l p ip e s w ith a d e ta c h a b le c o n ic a l n e t b a g o n th e fa r e n d . A b a m b o o p o le a tta c h e d to th e c e n tra l s h a ft s e rv e s a s a h a n d le fo r m a n u a l ro ta tio n o f th e e g g c o lle c to r a ro u n d th e c a g e .

T o re ta in s p a w n e d e g g s , a 5 .8 - o r 9 .8 -m d ia . c irc u la r h a p a n e t m a d e o f n y lo n n e ttin g (m e s h siz e , 1 m m ) is in s ta lle d in s id e th e 6 - o r 10- m d ia . flo a tin g n e t c a g e , re s p e c tiv e ly . A h a lf s a c k o f s a n d o r g ra v e l is d ro p p e d to th e b o tto m o f th e h a p a n e t lin in g to m a in ta in its c y lin d ric a l s h a p e . T h e h a p a n e t is s e t in p la c e at n ig h t. It is ta k e n o u t o f th e w a te r at d a y tim e o n a lte rn a te d a y s to e x te n d its life s p a n a n d to in c re a s e th e w a te r c irc u la tio n in th e c a g e s . A s s o o n a s e g g s a re

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fo u n d d u rin g s a m p lin g o f w a te r fro m th e c a g e , c o n firm in g th a t s p a w n in g h a s o c c u rre d , th e e g g c o lle c to r is o p e ra te d w ith in 10 m in . to a n h ou r.

D e la y in c o lle c tin g e g g s c a n d ra s tic a lly d e c re a s e e g g c o lle c tio n a s e g g c a n n ib a lis m b y m ilk fis h s p a w n e rs is k n o w n .

In la n d -b a s e d b ro o d s to c k ta n k s , th e p re s e n c e o f e g g s is c h e c k e d d a ily a ro u n d m id n ig h t b y s c o o p in g w a te r in a b e a k e r. W h e n p re s e n t, th e e g g s a re im m e d ia te ly c o lle c te d . T h e e g g c o lle c to r c o n s is ts o f 2 a irlift P V C p ip e s (4 -in d ia .) w ith o u tflo w s d ire c te d to a 1 m x 1 m x 1 m h a p a n e t s u p p o rte d b y a P V C p ip e fra m e . T w o e g g c o lle c to rs a re in s ta lle d in e a c h ta n k at th e c o rn e rs o p p o s ite th e w a te r in flo w . A d d itio n a l a irlift p u m p s a re in s ta lle d w ith th e ir o u tflo w s d ire c te d to w a rd s th e e g g c o lle c to rs . T h e h a p a n e ts a re ra is e d a n d rin s e d , a n d th e e g g s s c o o p e d o u t. T h e n e ts a re c le a n e d a n d s u n d rie d d u rin g th e d a y , th e n in s ta lle d a t n ig h t in a n tic ip a tio n o f th e n e x t s p a w n in g .

F e rtiliz e d m ilk fis h e g g s a re s p h e ric a l, fin e ly g ra n u la te d , p e la g ic , n o n -a d h e s iv e , tra n s p a re n t w ith a s lig h t y e llo w tin g e , a n d h a v e no o il g lo b u le . A d e v e lo p in g e m b ry o is v is ib le 10 h a fte r s p a w n in g . T h e tim e o f s p a w n in g m a y b e b a c k - c a lc u la te d fro m th e s ta g e o f e m b ry o n ic d e v e lo p m e n t a t th e tim e o f e g g c o lle c tio n .

F o llo w in g c o lle c tio n in c a g e s , th e c o n i

c a l b a g is d e ta c h e d a n d p la c e d in a p a il c o n ta in in g 1 0 l o f s e a w a te r. M ilk fis h e g g s s h o u ld n o t b e a llo w e d to s ta y o u t o f s e a w a te r fo r m o re th a n a fe w m in u te s . T h e e g g s a re re le a s e d fro m th e net b a g , ta k in g c a re to d is lo d g e e g g s s tic k in g to th e n e t. T h e c o lle c te d s a m p le is th e n a e ra te d to k e e p t he e g g s a flo a t, th e n tra n s fe rre d to a c o n ta in e r w ith 4 0 0 -I filte re d s e a w a te r.

D eterm in atio n of p ercen t egg viab ility

T h e p e rc e n ta g e o f v ia b le e g g s is th e ra tio o f th e to ta l n u m b e r o f liv e e g g s to th e to ta l n u m b e r o f e g g s . T h is v a lu e is u s e d to m o n ito r th e p e rfo rm a n c e o f a b a tc h o f e g g s a n d is a ls o u s e d in c o m p u tin g th e h a tc h in g ra te a n d th e n u m b e r of la rv a e s to c k e d .

V ia b le o r live e g g s a re tra n s p a re n t w ith a n a rro w p e riv ite llin e s p a c e a n d a b la s to d is c . D e p e n d in g o n th e tim e o f e g g c o lle c tio n , an e m b ry o m a y be v is ib le . D e a d e g g s a re o p a q u e , a n d th e u n fe rtiliz e d o n e s h a v e no p e riv ite llin e s p a c e .

T ra n sp o rt of eg g s

T h e h a tc h e ry m u s t b e lo c a te d as c lo s e a s p o s s ib le to th e b ro o d s to c k c a g e s o r ta n k s to m in im iz e m e c h a n ic a l d a m a g e o f e g g s d u e to h a n d lin g a n d tra n s p o rt.

T h e tim e s p e n t fo r p re p a rin g e g g s fo r tra n s p o rt a n d tra n s p o rt o f e g g s its e lf s h o u ld be k e p t to a m in im u m . A b o u t an h o u r p rio r to tra n s p o rt, p a c k in g p re p a ra tio n s s h o u ld b e u n d e rw a y fo llo w in g th e s e s te p s :

S h u t o ff th e a e ra tio n . S w irl th e w a te r in th e c o n ta in e r at le a s t o n c e to c o n c e n tra te d e a d e g g s a t th e b o tto m . S ip h o n o u t d e a d e g g s.

S e t a d o u b le -lin e d p la s tic b a g in s id e th e b a y o n g a n d fill w ith a b o u t 1 5 l filte re d s e a w a te r (s a lin ity , 2 8 -3 2 p p t).

S c o o p e g g s w ith a fin e m e s h (0 .6 -0 .8 m m ) s c o o p net. W ith a b e a k e r, ta k e a b o u t 150- 2 0 0 m l o f e g g s fro m th e s c o o p n e t a nd q u ic k ly tra n s fe r to th e b a y o n g . A b o u t 6 0 ,0 0 0 e g g s are c o n ta in e d in 1 00 m l.

S a tu ra te e a c h p la s tic b a g w ith o x y g e n a n d s e a l tig h tly w ith ru b b e r b a n d s .

B a y o n g b a g s s h o u ld be k e p t in th e s h a d e th ro u g h o u t tra n s p o rt. W a te r te m p e ra tu re in th e

(to page 8 please)

(6)

Milkfish broodstock... from p. 6

b a g s s h o u ld n o t g o b e y o n d 3 0°C .

In th e h a tc h e ry , e a c h p la s tic b ag is p la ce d in a h a tc h in g ta n k w ith 4 0 0 -l filte re d a n d w e ll- a e ra te d s e a w a te r. A fte r a 1 5 -m in a c c lim a tio n , th e p la s tic is o p e n e d a n d th e e g g s re le a s e d . T h e e g g s a re s to c k e d at 2 5 0 -3 0 0 p e r liter.

D e te rm in a tio n of hatching rate

M ilk fis h e g g s h a tc h b e tw e e n 20 a n d 24 h fro m s p a w n in g a t te m p e ra tu re s o f 2 6 -3 2 °C a nd s a lin itie s o f 2 9 -3 4 p p t.

T h e n u m b e r o f n o rm a l la rv a e (s tra ig h t b o d y a n d w ith o u t d e fo rm itie s ) a n d a b n o rm a l la rv a e (c u rle d b o d y ) is d e te rm in e d u n d e r a m ic ro s c o p e . T h e h a tc h in g ra te a n d p e rc e n ta g e o f n o rm a l la rv a e a re a ls o d e te rm in e d .

H a tc h in g ra te is th e ra tio o f th e to ta l n u m b e r o f la rv a e to th e to ta l n u m b e r o f liv e e g g s . T h e p e rc e n ta g e o f n o rm a l la rv a e is th e ra tio o f to ta l n u m b e r o f n o rm a l la rv a e to th e to ta l n u m b e r o f

la rv a e . B o th v a lu e s a re in d ic a to rs o f th e p e rfo rm a n c e o f a b a tc h o f e g g s.

P ostscript

R e s e a rc h o n b ro o d s to c k n u tritio n is v e ry im p o rta n t fo r fu rth e r re fin in g A Q D 's b ro o d s to c k m a n a g e m e n t te c h n iq u e s . T h e p ro d u c tio n of g o o d q u a lity e g g s a n d la rv a e d e p e n d s o n p ro p e r b ro o d s to c k n u tritio n . A n o th e r a re a fo r re s e a rc h is th e m e th o d o f o b ta in in g g o n a d a l m a tu ra tio n a n d s p a w n in g in m ilk fis h o u ts id e its b re e d in g s e a s o n . S u c c e s s in th e s e tw o a re a s -- b ro o d s to c k n u tritio n a n d o ff-s e a s o n m a tu ra tio n a n d s p a w n in g - w ill a u g m e n t th e s e e d s u p p ly of m ilk fis h p e rh a p s to th e p o in t w h e re d e p e n d e n c e o n n a tu ra l s u p p ly w ill b e m in im iz e d , if not, e lim i

n a te d .

Source: AC Emata, CL M arte, LMB Garcia.

1992. M a n a g e m e n t o f M ilk fis h B ro o d s to c k. SEAFDEC/AQD Aquaculture Extension Manual No.

20. 22 p.

References on milkfish available at SEAFDEC/AQD

P u b lic a tio n s

• Biology of Milkfish (Chanos chanos). T U B a g a rin a o . 1 9 9 1 . 9 4 p p .

O ld p ric e : P 2 0 0 U S $ 4 0 N e w p rice: P 1 00 U S $20

•Milkfish Hatchery Operations. R S J G a p a s in , C L M a r te. A E M N o . 1 7 , 1 9 9 0 . 2 4 p p . O ld p ric e : P 8 0 U S $ 3 0

N e w p ric e : P 4 0 U S$15

• Milkfish Abstracts.B R A IS . 1 9 8 8 . B ib lio g ra p h y S e r. N o . 9. 1 0 4 pp.

O ld p ric e : P 1 5 0 U S $ 3 5 N e w p ric e : P 7 5 U S$15

• Advances in Milkfish Biology and Culture.

J V J u a r io , R P F e rra ris , L V B e n ite z , E d s.

S e c o n d In te rn a tio n a l M ilk fis h A q u a c u ltu re C o n fe re n c e , Ilo ilo C ity , P h ilip p in e s , O c to b e r 1 9 8 3 . 2 4 3 p p .

O ld p ric e : P 2 3 0 U S $ 4 5 N e w p ric e : P 1 1 5 U S $20

V id e o ta p e s

•Caring for Milkfish Larvae.1 4 m in . O ld p ric e : P 4 2 0 U S $ 4 0

N e w p rice: P 2 0 0 U S $20

•Milkfish from the Wild to the Farm. 16 m in . O ld p ric e : P 4 8 0 U S $ 5 0

N e w p rice: P 2 0 0 U S $20

•Milkfish Fry Collection, Handling and Stor

age. 16 m in .

O ld p ric e : P 4 9 5 U S $ 5 0 N e w p rice: P 2 0 0 U S$20

•Milkfish Fry Acclimation and Fingerling Production in Freshwater. 10 m in . O ld p ric e : P 3 1 5 U S $ 3 0

N e w p rice: P 2 0 0 U S$20

•Milkfish Culture Systems. 1 0 m in . O ld p ric e : P 3 1 0 U S $ 3 0

N e w p rice: P 1 5 0 U S$15

O th e r re fe re n ce s on m ilkfish th a t w e re not pu b lish e d by A Q D are a va ila b le c/o T h e Library, S E A F D E C /A Q D , T ig b a u a n 5 021, Iloilo, P hilip

p ines. W hen w riting, p le a se in d ica te spe cific are a of interest, e.g., ca g e /p e n cu ltu re .