Southeast Asian Fisheries Development Center Aquaculture Department
SEAFDEC/AQD Institutional Repository http://repository.seafdec.org.ph
Institutional Reports Quarterly Research Reports
1977
Survival rates of different postlarval
stages of Penaeus monodon Fabricius
Primavera, Jurgenne
Aquaculture Department, Southeast Asian Fisheries Development Center
Primavera, J. H. (1977). Survival rates of different postlarval stages of Penaeus monodon Fabricius. SEAFDEC Aquaculture Department Quarterly Research Report, 1(2), 30-33.
http://hdl.handle.net/10862/2291
Downloaded from http://repository.seafdec.org.ph, SEAFDEC/AQD's Institutional Repository
S u r v iv a l ra te s o f d i f f e r e n t p o s tla r v a l stages o f P e n a e u s m o n o d o n F a b ric iu s
Jurgenne H. Prim avera
M a jo rity o f P. m onodon or sugpo fry produced by the hatcheries o f the A quaculture Departm ent at Tigbauan, Ilo ilo , Philippines are stocked in ponds at the Leganes Station.
Knowledge o f w hich postlarval stages o f sugpo yie ld m axim um survival rates upon stocking in the ponds is essential fo r harvest purposes. The earliest postlarvae which e x h ib it high survival rates in ponds as well as sturdiness in travel w ould be ideal fo r harvesting. Hardiness in transport depends n o t so much on age o f fry as on density, aeration, duration o f travel, and low ering o f tem perature in the container to m inim ize cannibalism. O f secondary consideration is the fa ct th a t the longer the rearing period in the hatchery, the higher the cost per fry . W ith the developm ent o f inexpensive feeds in the fu tu re , this should become o f m in o r importance.
The objective o f this study is to determine survival rates o f d iffe re n t postlarval stages upon stocking in the Leganes ponds. Commercial fry caught in the w ild and sold to pond operators are usually o f P20 stage. V illa lu z , et al. (1972) recommended the harvest o f P25 fry measuring 25 mm to ta l length fo r stocking in ponds. Fry o f the kurum a shrimp P. japonicus are harvested at P20-30 when they start to burrow in the b o tto m sand o f hatchery tanks in contrast to th e ir earlier pelagic life thereby injuring the telson or w alking legs by h ittin g against the concrete wall (F u jin a g a and Nakayama, 1974). It was also observed th a t survival is affected by size o f P. japonicus fry upon stocking in nursery ponds (80-100% at 1.1 to 6.0 g; 65-70% at 0.02 g.)
Twelve 3 m x 2 m x 2 m suspension nets made o f nylon clo th (mesh size = 0.1 m m ) were set up in a Leganes S tation pond (ave. w ater depth = 1m) by means o f 3 -m long poles stacked at distances approxim ating the area o f each net. The net b o tto m was fille d w ith topsoil at least 15 cm th ic k to simulate the pond b o ttom . A t least 60 cm o f the upper edge o f each net was above the w ater level to prevent m ix in g o f w ater inside and outside the net. P. m onodon o f stages P11, P15, P21 (fro m the hatchery) and P25 (fro m the w et lab) were stocked in the nets at 200/sq m or 1,200 fry /n e t. Due to lack o f fry , only one P25 net was stocked. Each net had tw o large dried m ia p i branches as shelter fro m predation and cannibalism fo r the young sugpo fry . Fresh lablab was fed at the rate o f one pail (approxim ately 5 kg) every fo u r days per net.
Analyses o f water tem perature, pH (colorim eter, standard solutions), oxygen (W inkler m ethod), total a lk a lin ity (m ethyl orange), and salinity (AgNO 3 titra tio n ) were taken regularly.
Juveniles were harvested after 40 to 52 days.
Harvest data show relatively higher survival rates fo r P15 and P18 compared to P11 and P25 w ith no significant difference between these tw o stages (Table 1, Fig. 1). The results fo r P25 may n o t be valid because the stock came fro m the w et lab in comparison to the other postlarval stages w hich were reared in the hatchery. Moreover, the P25 stock had no replicates and the net itself
(no. 10) was discovered to have many holes.
Fig. 2 shows the measurements o f tem perature, dissolved oxygen, pH, a lka lin ity and salinity in the pond during the experimental period; the ranges are found in Table 2. Water temperature was fa irly constant; pH was close to neutral, n o t exceeding 9. Dissolved oxygen remained s u ffic ie n t at levels o f 6 ppm and higher, reaching a m axim um o f 14.3 ppm. S alinity approxim ated th a t o f seawater except in the m iddle o f August when rains diluted it to 23 ppt.
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These prelim inary results p o in t to P15 as the best stage fo r harvest fro m the hatchery in terms o f high pond recovery and lesser expense in rearing compared to older postlarvae. Duplicate runs are being planned w ith more effective co n tro l o f feeding rate, predators and com petitors, volume o f water, etc. by means o f thorough pond drying, attachm ent o f a bamboo fram ew ork to the nets, and other improvements.
Fig. 1. Survival rates o f d iffe r e n t P. m onodon postlarval stages in suspension nets.
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Fig. 2. Physicochemical measurements in the Experim ental Pond, Leganes S tation
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T a b le 1. D a ta o n su sp e n sio n n e t s to c k s o f d iff e r e n t p o s tla rv a l stages o f P. m o n o d o n .
S u sp e n sio n N e t. N o.
P o stla rva l Stage
N o. o f D ays
I n itia l C o u n t
F in a l C o u n t
% S u rv iv a l R e m a rk s
1 P 11 4 0 1 2 0 0 4 5 1 3 7 .5 8 H a rv e s t n o t
th o ro u g h
2 P 11 4 0 1 2 0 0 8 7 0 7 2 .5 0 3 snakes
3 P 11 4 7 1 2 0 0 501 4 1 .7 5
4 P 15 4 6 1 2 0 0 5 9 5 6 5 .3 3 F ry s o ft s h e lle d ;
m a n y g o b y f r y ; 1 la rge M u g il (?)
5 P 15 4 6 1 2 0 0 871 7 2 .5 8
6 P 15 4 5 1 2 0 0 801 6 6 .7 5
7 P2 1 5 2 1 2 0 0 8 7 0 7 2 .5 0
8 P21 5 2 1 2 0 0 8 9 0 7 4 .7 1
9 P21 4 7 1 2 0 0 8 3 6 6 9 .6 7
10 P25 4 7 1 2 0 0 8 3 1 3 1 .7 5 M a n y h o le s in
n e t f r y fr o m w e t la b
T a b le 2. Ranges o f p h y s ic o c h e m ic a l m e a s u re m e n ts in e x p e rim e n ta l p o n d , 11 A u g u s t — 2 2 S e p te m b e r, 1 9 7 5 .
W a te r te m p e ra tu re
° C
p H D is s o lv e d o x y g e n , p p m
S a lin ity , p p t
T o ta l a lk a lin ity , p p m C a C O 3
2 7 - 3 1 .5 7 . 0 - 8 .9 5 .9 - 1 4 .3 2 3 - 3 3 .5 8 2 .5 - 1 2 9
L ite ra tu re C ited
A ra d a , M a x im o F. 1 9 7 2 . P r e lim in a r y o b s e rv a tio n s o n th e c u ltiv a t io n o f su g p o P e n a e u s m o n o d o n F a b ric iu s . T h e P h ilip p in e C ra fts m a n . Jan. 1 9 7 2 . p p . 6 - 7 , 9.
S h ig e n o , K . and Y . N a k a y a m a . 1 9 7 4 . P ro b le m s o f s h rim p c u ltu r e w it h spe cia l re fe re n c e t o cases in Ja p a n an d T h a ila n d (tra n s b y K. K u r o n u m a ; u n p u b lis h e d ).
V illa lu z , D. K ., A . V illa lu z , B. L a d re ra , M. S h e ik and A . G onzaga. 1 9 7 2 . P r o d u c tio n , la rva l d e v e lo p m e n t an d c u ltiv a t io n o f su g p o P en ae us m o n o d o n F a b ric iu s . P h il. J. Sci 9 8 :2 0 5 - 2 3 6 .
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