hi dear scientists;
I had two ponds of fish, ( 1 for catfish , and other for tilapia ), the water was renewed at a same time for tilapia and catfish , after 2 days the catfish were dead, any sign of illness, the quality of the spring water is good.
this white layer appeared after the death of the catfish, then became a condence, it is a sign of presence of chlorine or mucus related to the defense of catfish ?
please who has an explanation?
Age, growth, and mortality of introduced flathead catfish in ...
https://pubs.er.usgs.gov › publication
by TJ Kwak
Did we test for ammonia? May be densely stocked in pond so high production of ammonia. Yes chlorine is dangerous to fish but mortality should happened at the beginning of culture. People may poison the pond.
Hypoxia due to low dissolved oxygen and high ammonia concentration can predispose to fish mortality.
hi Bruce Robin Nyamweha thanks for anwering ,
there is not a problem of ammonia, the water was renewed two days before, we had the same conditions with tilapia but we did not find mortality
https://www.hindawi.com/journals/isrn/2012/861364/
Go through similar literature and try to maintain similar tank conditions.
@Bindia thanks for answering , I master the breeding conditions for catfish, this problem of total mortality I have never met
If total mortality of fish happens in a pond with out the incidence of disease means , logically there could be three reasons viz., severe dissolved oxygen problem or ammonia poison due to high pH levels or pesticide poisoning.
When did you stoked? Any spry of pesticide in room? Without observation of fish condition, it is very difficult to draw any concrete conclusion.
When any problem in water quality or feed is occured, it causes total mortality of catfish without disease.
These types of mass mortality ocuurs due to weather conditions means water quality. Please chech and maintain your water quality. I think it would be happened due to low water pH and DO and increasing Ammonia.
Hi, thank you for all your answers, finally it is a cause of pesticide! ph =8.07
we used silver nitrates to detect the chloride, so we got this color !!
Hi, Thanks for share your experience. What type of pesticides you use in this experiment? if you check Do level and other water parameters please share with me.
Hi, if the mortality became suddenly
May be due to
1_toxicity (pesticide,poisonous plant, toxic algea, toxic heavy metal, toxic chemical)
2_virus
3_Bad water quality(PH,ammonia,)
@samah attia thanks for the answer, the catfish was exposed to the same conditions as the tilapia, after the mortality, I did spectral sweep, I got almost the same curve for tilapia and spring water, so for the catfish I had a totally different curve, the cause is still unknown, but very possible because of pesticide. pH =8,07
- Badges
- Science topic
- Similar topics
- Correction