Southeast Asian Fisheries Development Center Aquaculture Department
SEAFDEC/AQD Institutional Repository http://repository.seafdec.org.ph
Institutional Reports Quarterly Research Reports
1977
Effects of furanace on Brachionus
Baticados, Ma. Cecilia
Aquaculture Department, Southeast Asian Fisheries Development Center
Baticados, M. C., Gacutan, R. Q., & Gutierrez, P. J. (1977). Effects of furanace on Brachionus.
SEAFDEC Aquaculture Department Quarterly Research Report, 1(1), 34–35.
http://hdl.handle.net/10862/2282
Downloaded from http://repository.seafdec.org.ph, SEAFDEC/AQD's Institutional Repository
Effects of furanace on Brachionus
By
M a . C ecilia Baticados, R .Q . G acutan and P. J. G u tie rre z
F u ra n a c e is o n e o f th e c h e m o th e ra p e u tic s b e in g te s te d t o r c o n tr o l o f b a c te ria l and fu n g a l diseases o f P enaeus m o n o d o n la rvae a t S E A F D E C . I t has a lre a d y been fo u n d e ffe c tiv e a g a in st a w id e range o f p a th o g e n ic b a c te ria and fu n g i in fis h (1, 2 ), and in th e fre s h w a te r p ra w n , M a c r o b r a c h iu m r o s e n b e rg ii (3 ).
T ig e r p ra w n (P. m o n o d o n ) la rvae u tiliz e B ra c h io n u s , a r o tife r , as fo o d in th e Z o e a 3 and m y s is stages w h e n th e y ch a n g e fr o m an h e rb iv o ro u s t o an o m n iv o ro u s d ie t. T h e e ffe c ts o f fu ra n a c e o n th e la rva e have a lre a d y been in v e s tig a te d (4). T h e p re s e n t w o r k a im s t o s h o w th e e ffe c ts o f fu ra n a c e b n th e p o p u la tio n g r o w th o f B ra c h io n u s .
C u ltu re s o f B r a c h io n u s w e re o b ta in e d fr o m 2 - to n fib e rg la s s ta n k s m a in ta in e d in th e N a tu ra l Feeds P ro je c t. T h e r o tife r s w e re fe d w i t h C h lo r e lla a t a d e n s ity o f 1 - 2 x 1 0 6 c e lls /m L . F ive lite rs o f th e c u ltu r e w a te r w e re p la c e d in each o f 4 w h ite , c ir c u la r , 1 5 2 x 3 0 4 m m p la s tic basins. T h e m e a n in it ia l d e n s itie s o f th e r o t if e r ran ge d f r o m 2 6 .5 t o 3 8 .5 in d iv id u a ls /m L . T h e c o n c e n tra tio n s o f fu ra n a c e (p u rc h a s e d fr o m D a in ip p o n S e iy a k u , O saka) w e re 0, 1, 2 an d 3 m g /L . T h e c u ltu re s w e re v ig o r o u s ly a e ra te d .
P o p u la tio n g r o w th w as o b se rve d a fte r 3 , 6 , a n d 9 h o u rs o f e x p o s u re . T h e c u ltu re s w e re th o r o u g h ly m ix e d b e fo re sa m p le s w e re ta k e n t o e n su re an a lm o s t e q u a l d is tr ib u tio n o f th e r o tife r s in th e w a te r. T o fa c ilita te th e c o u n tin g o f th e r o t if e r , on e d r o p o f L u g o l's s o lu tio n w a s ad d e d to each sa m p le . T h is im m o b iliz e s th e r o t if e r as w e ll as s to p s f u r t h e r r e p r o d u c tio n . In d iv id u a ls w ith o n ly th e lo r ic a l e f t o r w it h b a d ly d e fo r m e d lo r ic a w e re c o n s id e re d de ad . P o p u la tio n c o u n ts w e re d o n e u s in g a S e d g w ic k -R a fte r c o u n tin g c h a m b e r.
T h e m e a n d e n s itie s a n d p e rc e n ta g e s u rv iv a l o f B ra c h io n u s in all tre a tm e n ts a t a ll d u ra tio n s o f e x p o s u re are s h o w n in T a b le 1 a n d 2.
T a b le 1. M e a n d e n s itie s o f B ra c h io n u s p o p u la tio n s e xp o se d t o d if f e r e n t le ve ls o f fu ra n a c e *
D u r a tio n o f E x p o s u re
0 m g /L 1 m g /L 2 m g /L 3 m g /L
A liv e D ead A liv e D ead A liv e Dead A liv e Dead
0 h r. 3 8 .5 5 .9 2 6 .5 2 .2 2 7 .8 2 .5 2 8 2 .5
3 h r. 3 1 .1 4 .5 2 3 .4 3 3 0 .4 2 .4 2 9 .4 3 .5
6 h r 3 0 .4 3.1 3 1 .8 5 .2 3 7 .2 2 .8 3 0 .8 4 .6
9 h r 3 1 .9 5 .4 2 9 .5 3 .6 3 9 .8 4 .6 3 8 5 .6
* B ased o n 4 t r ia ls ; n o s ta tis tic a l d iffe re n c e s e x is t a m o n g th e m e a n d e n s itie s a t 1% s ig n ific a n c e le ve l.
3 4
Table 2. Mean percentage survival o f Brachionus populations exposed to d iffe re n t levels o f furanace*
D uration o f Exposure
0 m g/L 1 m g/L 2 m g/L 3 m g/L
Alive Dead Alive Dead Alive Dead Alive Dead
0 hr 86 14 92 8 90.7 9.3 91 9
3 hr 88.2 11.8 90.4 9.6 95.5 8.5 89.5 10.5
6 hr 89 11 87 13 88.5 11.5 88.5 11.5
9 hr 86.5 13.5 89 11 91 9 88.25 11.75
* Based on 4 trials; no statistical differences exist among the mean percentage survival at 1% significance level.
Am ong the d iffe re n t durations o f exposure, the percentage survival o f the populations in the furanace baths were highest after 3 hr. There were slight increases in the co n tro l and 2 m g/L and slight decreases in 1 and 3 m g /L The differences in the mean densities are statistically insignificant at .01 significance level.
A fte r a 6-hr exposure, the co n tro l population reached its peak density w ith a survival o f 89%.
Populations in furanace baths decreased to 88.5% in both 2 and 3 m g/L, follow ed closely by 87% in 1 m g/L. Again, no statistical differences exist among all the levels.
The mean percentage survival in 1 and 2 m g/L increased (89% and 91%, respectively) after a 9-hr exposure, w hile those in the co n tro l and 3 m g/L decreased to 86.5% and 88.25%, respectively.
There were no marked differences in appearance noted among the individuals in furanace baths and those in the co n tro l.
L ite ra tu re C ite d
