Questions and Answers
Which of the following is a bacterial infection common in warm water and affects fish with weakened immune systems?
Columnaris
What is the preferable total alkalinity level for water to buffer against pH change?
100mg/L CaCO3
What is the minimum oxygenation level required for healthy fish?
6mg/L
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Study Notes
Important Water Parameters for Fish Health
- Soft water is generally 300mg/L CaCO3 and levels >100mg/L CaCO3 are better for buffering to minimize pH swings.
- Total alkalinity is the total concentration of carbonates and bicarbonates in the water and is directly related to hardness and is expressed in mg/L CaCO3.
- Total alkalinity is an indicator of the ability of the water to buffer against pH change and in marine tanks is referred to as the ‘marine reserve’.
- It is preferable to ensure the total alkalinity is >100mg/L CaCO3, and marine tanks require at least 200mg/L alkalinity.
- Oxygenation may be measured using chemical test kits or an electronic meter with a polarographic probe.
- Oxygenation is measured in ppm or mg/L, and levels should be at least 6mg/L for healthy fish.
- Anoxia occurs at levels <2mg/L, and it affects all ages of fish, although yearlings are most susceptible.
- Columnaris is a bacterial infection caused by Flavobacterium columnare and is common in warm water.
- It affects fish with weakened immune systems, and the symptoms include lethargy, loss of appetite, and the development of white or grey patches on the skin.
- Spring Viraemia of Carp (SVC) is caused by a rhabdovirus and affects cyprinid fish, particularly carp.
- It is a listed disease under ‘The Aquatic Animal Health (England and Wales/Scotland) Regulations 2009’ which controls movement on and off infected premises.
- Lymphocystis is caused by Iridoviruses and affects fresh water and marine fish, mainly from tropical climes.
- It produces a series of nodules due to enlargement of fibroblasts within the dermis causing a series of white-grey coalescing irregular masses, often on the fins, but can occur anywhere on the body.