Top 10 common symptoms of saltwater fish disease

Published by : Michael on 29 May 2020

Saltwater aquarium fish disease is common. Reef King Aquatcis wants to be able to help you identify any potential symptoms that your saltwater fish could be showing, so that any sign of early detection can be treated with the correct diagnostic. 

1. Pop Eye

When a saltwater fish has an enlarged eye protruding from its socket this is commonly known as a ‘pop eye’ and scientifically known as Exophthalmia.

Pop Eye is the result of an eye infection, caused by an injury to the eye such as a scratch or abrasion. It can be treated with a major water change and a broad spectrum of antibiotics that will kill the invading bacteria. 

Always ensure regular water changes using aquarium salt, correct water chemistry, good maintenance, quarantine infectious fish, and feed-high quality food.

2. Cloudy Eye

Similarly, to Pop Eye, Cloudy eye is also the result of a bacterial infection from an injury of the eye. In fact, cloudy eye could be caused by an injury to any part of the fish body. An open wound allows bacteria to enter the body of the fish and cause infection visibly present in the eye. Treatment is the same as pop eye. 

3. White Spot

If you notice tiny white spots or a white powdery appearance on your saltwater fish, this is a strong signal of marine parasites, commonly known as marine white spot disease or Ich. Fish that have white spot or Ich also tend to respire heavily, scrape against rocks, appear restless and can lose their appetite.

To treat the fish affected by the white spot disease you can use copper dosing, it is known to be effective on parasites that live off saltwater fish, and it eliminates crypto organisms in their free-swimming stages when they're looking to infect other fishes. Please note that although copper dosing can help treat early stages of Ich, it is far more difficult for the copper to work if the marine parasites have burrowed deeply into the tissues of any fish affected by the white disease.

4. Not Eating

If you have brought new saltwater fish for your marine aquarium it can be normal for them to have a lack of appetite or none at all for the first couple of days settling in. However, if this continues, consider this a major warning, it could be a sign of a serious problem. Fish refusing to eat leads to starvation, which eventually results in death. To treat your non-eating fish, it's best to determine the reason why and find the best remedy. This can be quite challenging, but the most common causes can be a direct result of fish disease, stress, or quite simply your feeding the wrong food or frequency.

Keep a close eye on the non-eating fish and If you suspect your fish is diseased, learn how to identify and treat the disease. If you suspect it's  stress (erratic swimming and hiding) then your tank could be overcrowded for the fish or too small. Moreover, your fish is being bullied by aggressive fish. Better late than never, ensure you find out if the fish you just purchased can live harmoniously with the other fish in your tank, and if it's in the right environment for your fish (size wise and the number of fish you have). If you suspect it is the food your feeding, check what food is good for specific fish and try introducing it into the tank. 

5. Faded Colouration

Faded colours in fish can be common at night or when stressed. Faded colouration comes and goes making it harmless. However, if this continues for a long period of time, this is a symptom of a more serious condition, which, unfortunately can be difficult to not only identify the problem, but to find a remedy. Often in cases like this we can assume common factors that include inadequate diet, inadequate tank lighting or poor water quality. 

6. Worn fins

Frayed fins or red fins on fish are often caused by Ammonia burns. When ammonia in a saltwater tank reaches a toxic level the fish's fins are chemically burnt removing protective mucus from the fins surface. Treating Ammonia poisoning in your tank is crucial. Do a big water change, lower the PH level and neutralize the Ammonia levels.

7. Rapid Breathing

Lack of oxygen can cause fish to breath rapidly. When parasites irritate a fish's gills, the fish's immune system detects danger and produces more mucus to defend itself. However, if a fish's gills are clogged by mucus, it can quickly lead to suffocation.

8. Raw spots

Raw spots on a fish are infected open sores often caused by parasite infestation. The treatment is the same as white spot. 

9. Side swimming, Bloated or abdominal swelling

If you witness a fish swimming on its side, this is a sign of a bladder infection, often referred to as swim bladder disease. This can be caused by overfeeding, feeding the wrong foods and constipation, or lack of decompression when captured in deep waters. If you witness bloating or abdominal swelling, this could be a serious condition called Dropsy where an accumulation of fluids inside the fish body have built up and could lead to organ failure. To treat Dropsy, you could try Epsom salt, it's not guaranteed to work but it may help as it acts like a laxative to draw out the excess fluid. 

10. Rock scratching

When a fish scratches on rocks, it is a sign that the fish is irritated by an itch, usually a result of white spot or Ich as mentioned previously. Look out for tiny white spots, and treat accordingly.