marine velvet

Marine Ich

This article deals not only with Marine Ich (Cryptocaryon Irritans) but also with another common parasite, Marine velvet (Amyloodinium Ocellatum).

There is nothing more horrifying than looking at your marine aquarium only to realize one or more of your fish have a parasite of some sort. Both marine ich and marine velvet have the capability to wipe out all your fishes in the aquarium. Thankfully, there are ways to deal with them.

The most effective method is through preventive measures. Which simply means quarantining all newly purchased fish for a period of time. To read more on quarantine tanks, read here.

Unfortunately, a great many marine aquarium hobbyists do not quarantine their fishes. Sometimes they get away with it and sometimes they don't. Before we tackle these parasites head on, lets find out what marine ich and marine velvet actually are, their life cycles and breeding habits.

Marine Ich

The dreaded marine ich is actually a parasitic ciliate organism. They only affect fish, invertabrates such as shrimp, crabs and corals are entirely safe. The most obvious sign that you fish has ich are the white spots that are present on its body. Other signs include scratching, flesh wounds from scratching, clamped fins and rapid breathing. There are a few species of fish that seem to be highly susceptible to this parasite, namely the surgeonfish family. On the other end of the spectrum some species are highly resistant, such as the mandarin fish, sharks and moray eels.

To effectively deal with these parasites, we have to understand their life cycle and environmental factors that affect them. As white spots on the fish, they feed until it is time to drop off and breed. The amount of time this parasite stays at this stage depends on temperature. The higher the temperatures, the faster they drop off. When it drops off, it begins looking for a suitable location to begin breeding.

Once this location has been found, it will encyst and begin dividing itself into hundreds of duplicate copies. These babies must find prey within a day or they will perish. In a closed system like an aquarium, this cycle can repeat itself until all fish are wiped out.

Marine Velvet

Marine velvet has a life cycle that is very similar to marine ich. However, it is far deadlier and more difficult to eradicate as many have experienced. Fish can succumb to this parasite in days. They are a parasitic dinoflagellate organism that are much smaller than marine ich and can look like tiny sugar sized spots on the fish. Symptoms that your fish may have marine velvet are the obvious spots, scratching and heavy breathing. This is because they normally latch onto the gills, bringing death via suffocation or through damage to the gills themselves.

Their life cycles are the same as marine ich with one important exception. After the babies have erupted into the water column, they can survive up to two weeks without finding prey. Also of equal importance, they are photosynthetic and are able to survive for long periods with adequate lighting.

Treatment

Treatment for both parasites are somewhat similar. However, eliminating marine velvet will take longer as they are harder to kill. If the infected fish were in your display tank then you must quarantine every single one of your fish from that aquarium. Many effective medicines are not reef safe and leaving the infected fish in the aquarium will normally make things worse. The tank should remain fishless for a period no shorter than a month. Without any fish to prey one, your aquarium should be clear of any parasites after the month is up. There are a variety of methods and medicines we can use to tackle both these parasites.

Dips

There are a few dips we can use to assist in the removal of both marine velvet and marine ich. They involve the use of formaldehyde and freshwater. Formalin can be effective but they are a dangerous substance that is carcinogenic. Maintain 25ppm during the dip for a length of about half an hour. Freshwater dips are extremely effective with about 80 percent of parasites dropping off in about 5 minutes. It is also extremely important to ensure that the PH and the temperature is the same as the quarantine water. If the PH is off by a large margin, they may experience shock.

Specific Gravity

Lowering the specific gravity to 1.009 for a few weeks has been shown to be effective. However, it is only effective against marine ich. Lower the specific gravity to 1.009 over three days and mantain for a month. Once all traces of marine ich has been eradicated, slowly raise specific gravity.

Medicine

The most widely used and effective substance use to kill both external parasite is (*See Below) Copper. However, it is a toxic substance that will kill invertabrates. Using copper is somewhat tricky as the dosage must be correct. Copper test kits can help achieving the desired levels of copper in the quarantine tank. (*)Salifert produces some of the most accurate test kits on the market and are a highly reputable brand. The dosage must be within 0.2 to 0.3 ppm for it to be effective. Any higher and it is lethal to the fish. Any lower and it is not effective.

A second type of medicine used revolves around non copper based variants. These types may include formaldehyde, aldehyde, malachite green and a host of other ingredients. Normally not as effective as copper, they are easier to administer and safer for the fish. Two brands that are recommended include (*)Rid Ich and (*)Paraguard.

During treatment, always maintain good water quality and ensure the treated fish is eating well. 30% to 50% water changes should be performed every week during which time it is recommended to take out all pvc pipes and elbows for a good cleaning. For best results, treat for a solid month.

Return To Marine Aquarium Fish