Blackening of Discus Fish
- Discus fish develop Black Spot on their body.
- The development of black spots reduces the beauty of the fish.
- The developments of black spots are also known as Black Peppering Effect
Factors responsible for the Blackening of Discus Fish
Either of two factors is responsible for the blackening effect:
- Due to Black Background of Aquarium: Non-fatal
- Due to Viral Infection: fatal
NORMAL CONDITION OF DISCUS (DAY 1): NO BLACKENING/PEPPERING
SAME FISH SHOWING BLACKENING/ PEPPERING EFFECT (DAY 5): DUE TO ENVIRONMENT
How does the background of an aquarium cause the Black Peppering of the Discus fish?
- Some Discus fish have the capacity to Camouflage
- The Camouflage capacity makes them adjust themselves with their environment and in the presence of dark environments such as black background and bottom they show black peppering effect
- The camouflage capacity of Discus fish is due to the presence of pigeon blood gene
How virus infection does cause mortality in the Discus fish?
- The infection caused by the virus is known as Discus Plague or Black Disease
- The infected fish have the following symptoms:
- Heavy breathing: 3 breaths per seconds
- Loss of appetite: stop feeding
- Black spots all over the body
- Hiding at the corner of the aquarium
- Excessive mucus/slime production
- Scratching behaviour against hard objects in the aquarium
- Suppressing immunity
- Later become vulnerable to Secondary pathogens like:
- Parasites: Spironucleus spp, ichthyophthirius multifiliis etc.
- Bacteria: Aeromonas hydrophila,
- Fungus: Fusarium solani, F. oxysporum and F. moniliform
- An infection like fin/tail rot begins
- White patches are found
- Smelly water
- Mortality begins
The disease spreads rapidly from one tank to another in a short span of time (2-3 days).
Cure for the Diseases
- By changing the dark coloured environment to white coloured environment
- Best colour of environment: Light blue background and whitish bottom
- With the blackish environment: the peppering effect in fish will increase with time
- Black peppering effect may fade with corrective measures but may not go completely
- Feeding with high-quality feed will help further
- Separate the affected fish immediately
- Exchange water daily (10-40% depending on the severity of the environment and disease)
- Provide quality feed and remove excess feed immediately
- Treat with the AZOO Magic Treatment
- Increase temperature to 30ᵒC
- Cure the secondary infection using specific treatments recommended for them
- 50-100% water exchange is recommended daily before adding new doses of drugs/aqua-medicines
Guided by: Dr. Himadri Saha, Assistant Professor, Department of Aquatic health and Environment, College of Fisheries, CAU(I), Lembucherra. email: email@example.com