Jay Hemdal
10K Club member
Staff member
Forum Moderator
Excellence Award
Expert Contributor
Article Contributor
Fish Medic
Fish treatment variations by species and medication
Not all fish species are able to be treated with generally used medications. There are some sensitivity issues between species that must be managed. However, sensitivity to a drug can also be seen in different dosages, how the drug is applied and other factors. Additionally, many of these drug sensitivities are based on personal opinion, which is in turn based on possibly uncontrolled variables. The following list are some of the better known instances of drug sensitivity in fishes. These are listed by fish species, but also drug type:
Angelfish: Pygmy angelfish are sensitive to ionic copper. If used on these species, it must be ramped up slowly, over 72 hours. A better choice would be amine-chelated copper products like Coppersafe or Copper Power.
Chloroquine phosphate: This drug will usually inhibit nitrifying bacteria, so ammonia levels must be monitored during treatment. Some fish have shown sensitivity to doses above 12 ppm (lionfish and wrasses)
Eels: Most species of eel are sensitive to copper medication. The common issue is that copper causes them to temporarily stop eating. With an otherwise healthy eel, this is not an issue as eels can tolerate long fasts. However, if the eel is skinny to begin with, a long fast could prove fatal.
Flashlight fish: Do not expose flashlight fish to fenbendazole, antibiotics or copper.
Formalin: Formalin is toxic to people and must be used with care. Additionally, it is a reducing agent, it removes oxygen from the water and may disrupt some chemical bonds, such as chelated copper products. Formalin is based on time versus temperature. For tropical marine fish, do NOT use as a dip higher than 167 ppm for one hour. Some web sites give the dose at 250 ppm, but that is an error, that dose is only used for cold water fishes.
Hydrogen peroxide: Shrimp are extremely sensitive to even low doses of oxidants, including hydrogen peroxide.
Larval fish, any species: There is an issue with small fish having a higher surface to volume ratio. In theory, smaller fish are therefore more sensitive to any medications dosed in the water.
Lionfish: This group of fish is sensitive to ionic copper (not amine-chelated copper) as well as higher doses of chloroquine.
Mandarin dragonets: Amine-chelated copper or hyposalinity treatments are tolerated by these fish, however, holding these in a bare quarantine tank is the core issue. Especially with wild caught mandarins, they just do not survive in bare tanks, without live food to graze on.
Panacur (Fenbendazole): Do not use it as a bath on bottom-dwelling fishes; darters, catfish, etc. Do not use on flashlight fish or pencil fish. Do not use it with any invertebrates, as there are reports of toxicity seen in these animals. Additional species may be found to react poorly to this medication.
Sharks and rays: All copper products should be avoided with these fish. Additionally, they do not tolerate hyposalinity.
Seahorse, pipefish: Like mandarins, these fish do not do well in standard bare quarantine systems due to their need to graze on small food items. They are also reported not to handle copper well.
Trichlorfon (Dylox or Metrifonate): These products are dangerous for aquarium use; toxic to the aquarist and causing sensitivity reactions in many species of fish. Other treatments need to be considered first.
Wrasse: This group of fish is frequently associated with a sensitivity to praziquantel. However, it is not clear if the fish are sensitive to the drug itself, or to the low dissolved oxygen levels associated with it being used with certain solvents like glycol, alcohol or DMSO. Wrasse are also sensitive to higher doses of chloroquine.
Our standard quarantine protocol is here:
www.reef2reef.com
Not all fish species are able to be treated with generally used medications. There are some sensitivity issues between species that must be managed. However, sensitivity to a drug can also be seen in different dosages, how the drug is applied and other factors. Additionally, many of these drug sensitivities are based on personal opinion, which is in turn based on possibly uncontrolled variables. The following list are some of the better known instances of drug sensitivity in fishes. These are listed by fish species, but also drug type:
Angelfish: Pygmy angelfish are sensitive to ionic copper. If used on these species, it must be ramped up slowly, over 72 hours. A better choice would be amine-chelated copper products like Coppersafe or Copper Power.
Chloroquine phosphate: This drug will usually inhibit nitrifying bacteria, so ammonia levels must be monitored during treatment. Some fish have shown sensitivity to doses above 12 ppm (lionfish and wrasses)
Eels: Most species of eel are sensitive to copper medication. The common issue is that copper causes them to temporarily stop eating. With an otherwise healthy eel, this is not an issue as eels can tolerate long fasts. However, if the eel is skinny to begin with, a long fast could prove fatal.
Flashlight fish: Do not expose flashlight fish to fenbendazole, antibiotics or copper.
Formalin: Formalin is toxic to people and must be used with care. Additionally, it is a reducing agent, it removes oxygen from the water and may disrupt some chemical bonds, such as chelated copper products. Formalin is based on time versus temperature. For tropical marine fish, do NOT use as a dip higher than 167 ppm for one hour. Some web sites give the dose at 250 ppm, but that is an error, that dose is only used for cold water fishes.
Hydrogen peroxide: Shrimp are extremely sensitive to even low doses of oxidants, including hydrogen peroxide.
Larval fish, any species: There is an issue with small fish having a higher surface to volume ratio. In theory, smaller fish are therefore more sensitive to any medications dosed in the water.
Lionfish: This group of fish is sensitive to ionic copper (not amine-chelated copper) as well as higher doses of chloroquine.
Mandarin dragonets: Amine-chelated copper or hyposalinity treatments are tolerated by these fish, however, holding these in a bare quarantine tank is the core issue. Especially with wild caught mandarins, they just do not survive in bare tanks, without live food to graze on.
Panacur (Fenbendazole): Do not use it as a bath on bottom-dwelling fishes; darters, catfish, etc. Do not use on flashlight fish or pencil fish. Do not use it with any invertebrates, as there are reports of toxicity seen in these animals. Additional species may be found to react poorly to this medication.
Sharks and rays: All copper products should be avoided with these fish. Additionally, they do not tolerate hyposalinity.
Seahorse, pipefish: Like mandarins, these fish do not do well in standard bare quarantine systems due to their need to graze on small food items. They are also reported not to handle copper well.
Trichlorfon (Dylox or Metrifonate): These products are dangerous for aquarium use; toxic to the aquarist and causing sensitivity reactions in many species of fish. Other treatments need to be considered first.
Wrasse: This group of fish is frequently associated with a sensitivity to praziquantel. However, it is not clear if the fish are sensitive to the drug itself, or to the low dissolved oxygen levels associated with it being used with certain solvents like glycol, alcohol or DMSO. Wrasse are also sensitive to higher doses of chloroquine.
Our standard quarantine protocol is here:
Current Quarantine Protocol
2023 Quarantine Procedures Jay Hemdal David Scarborough Protozoans (Cryptocaryon/ich, Amyloodinium/velvet) and Metazoan trematodes/flukes are by far the most common parasites found on newly acquired fish. A carefully managed quarantine process can effectively eliminate these parasites before...
www.reef2reef.com
