Badman's note. Pandora an old friend of the site is currently unable to further her work and her former webhost is on a temporary Hiatus. Working with her former host and friend I was able to recreate much of Pandoras hard work and once again offer most of this valuable resource to all hobbyist. I cleaned up the tables some and removed any broken links, all text is original.

Disease

I've been working on a photo archive of fish diseases that people send me or allow me to use from their sites. This list and archive of photos is not meant to be exhaustive or comprehensive. Please note also that some diseases have multiple manifestations (Columnaris, NTD, Fish TB, to name a few), and may vary in presentation from fish to fish; others are not true "diseases" caused by a single organism, but rather signs that could point to a number of causative organisms (dropsy, pop-eye). Click on the thumbnails, and you will be linked to the larger photos (if it was larger to begin with, that is, I can't enlarge photos any larger than they were when sent to me, because this will not improve resolution).

THIS IS AN ONGOING PROJECT THAT IS ALWAYS BEING ADDED TO. IF YOU HAVE A RELATIVELY CLEAR PHOTO OF A FISH WITH A DISEASE THAT YOU THINK I CAN USE, PLEASE EMAIL ME.

FUNGAL INFECTIONS

Common Name:	Body Fungus
Pathogen/Cause:	Saprolegnia spp.
Physical Signs:	A very fuzzy growth which projects from the skin or fins of the fish. Usually has the "fluffy" appearence of food molds, can be white or grey. Needs to be differentiated from "false mouth fungus" Columnaris (see above). True parasitic fungus prefers to grow on already dead tissue and will often coexist with bacterial infections.
Behavioral Signs:	Usually not severely affected until later stages.
Potential Treatment:	Many formulations available, including brand names: Jungle Fungus Guard, Mardel Maroxy, Aquarium Pharmaceuticals Fungus Cure and generic formulations usually containing methylene blue.
Other Notes:	Fungal infections are relatively rare but do happen in already weakened fish. They will be very distinct in appearence, as opposed to Columnaris, which is probably far more commonly seen in the aquarium (less protrusion of fibers, just a ragged fuzzy appearence). See photos to differentiate.
Photos: Courtesy of Chuck's Pets & Hobbies	Courtesy of Pet Care Forum
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Common Name:	Cotton Fin Fungus
Pathogen/Cause:	Various, often Saprolegnia spp.
Physical Signs:	Cotton-like "fluffy" or wispy growth trailing on fins of fish. Can gradually promote decay of tissue.
Behavioral Signs:	Usually not severely affected until later stages.
Potential Treatment:	Many formulations available, including brand names: Jungle Fungus Guard, Mardel Maroxy, Aquarium Pharmaceuticals Fungus Cure and generic formulations usually containing methylene blue.
Other Notes:	Prefers to attack already damaged or injured tissue. Most important action is to do water changes and increase circulation of the system. Saprolegnia prefers to live in stagnant water. Sometimes improvement of water quality alone will erradicate the disease.
Photos:   Courtesy of Jungle Labs	Courtesy of Joe from Badman's Tropical Fish	Courtesy of Jungle Labs	Courtesy of Michele Hartley (very bad case of fungal infection on caudal fin; likely secondary to erosion by primary bacterial infection)
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VIRAL INFECTIONS/TUMORS

Common Name:	Lymphocystis, Cauliflower Disease
Pathogen/Cause:	Lymphocystis spp. (A DNA Iridovirus).
Physical Signs:	Viral infection that causes cells to become megaloblastic, thus forming small tumors (bumps or growths), often along the lateral line or the pedicle, where the fin meets the body. The tumors sometimes take on the appearence of tiny cauliflowers, thus the name.
Behavioral Signs:	Lethargy, general symptoms, may affect balance and swimming control if along the lateral line.
Potential Treatment:	Frequent water changes and reduction of ammonia and nitrites in water may reduce stress to help the fish battle the infection and shrink tumors on its own. Interestingly, cyprinids & catfish which have been studied appear to be resistant.
Other Notes:	Watch for secondary bacterial infections. Often attacks large fish fed with live foods. Cichlids are especially susceptible. Please check World Cichlid's page on HITH/HLLE which has much more detailed info, theories, and potential treatments of this disease. Also, Dr. Barb's Flippers and Fins Site has some more info for curious minds.
Photos: Courtesy of 2la from The Age of Aquariums (not characteristic of usual presentation of disease)	My own photo (Taken at a local pet store which will remain unnamed.)	Courtesy of Tom Choi	Courtesy of Lars Lonstromm of the Laboratory of Aquatic Pathobiology
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Common Name:	Solid tumors of unknown cause
Pathogen/Cause:	Not fully understood in fish or man. Many oncoviruses may be suspect in turning off genes involved in tumor suppression. In fish, just as in other animals, may be benign or malignant (cancerous).
Physical Signs:	Growing mass of tissue, can occur on almost any part of the body.
Behavioral Signs:	Usually not overtly affected unless the tumor is very fast growing internally, or obscures vision, feeding, or swimming.
Potential Treatment:	None for most fish. Seek veterinary help for large and/or expensive fish. Surgery often the only cure, though rarely will shrink back on its own.
Other Notes:	Not much known about the fish oncology at this time. Watch tumor closely for fast, uneven growth of tumor. If it keeps the fish from feeding and/or swimming, consider euthanasia.
Photos: Courtesy of The Welborn Pet Hospital.	Courtesy of Joel Rose	Courtesy of Ron Travelbee from Badman's Tropical Fish	Courtesy of Mike Hottovy
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EXTERNAL ARTHROPOD PARASITES

Common Name:	Anchor Worm
Pathogen/Cause:	Lernea spp.
Physical Signs:	Actually, lernea is a copepod (crustacean arthropod) rather than a true worm. It looks like a small whip (a few mm to under an inch long) attached to the fish at the mouth end and with a forked tail.
Behavioral Signs:	Usually none noted unless very severe with secondary infections.
Potential Treatment:	May be physically removed, but will cause great stress to the animal, and must be done carefully and with a dab of antibiotic over the wound afterwards. Brand name formulations like Jungle Parasite Guard and Aquarium Pharmaceuticals may also help.
Other Notes:	Rarely seen in pet fish not kept outdoors (in ponds), and usually then only in ones that have been fed live foods.
Photos: Courtesy of The Dept. of Western Australian Fisheries	Courtesy of Qian Hu Inc.	Courtesy of "JJ"	Courtesy of John Childers (this photo is one of the best high-resolution photos I've ever seen of its kind; really captures the anatomy of this parasite in detail)
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Common Name:	Fish Louse
Pathogen/Cause:	Argulus spp.
Physical Signs:	A flat disk-shaped arthropod parasite with many legs. On the fish itself it is barely noticeable only as a flat, dull colored bump that you may just think is a part of the fish, unless you see the legs themselves or the disk moving around on the body.
Behavioral Signs:	Usually none noted unless very severe with secondary infections.
Potential Treatment:	May be physically removed, but will cause great stress to the animal, and must be done carefully and with a dab of antibiotic over the wound afterwards. Brand name formulations like Jungle Parasite Guard and Aquarium Pharmaceuticals may also help.
Other Notes:	Rarely seen in pet fish not kept outdoors (in ponds), and usually then only in ones that have been fed live foods. Crustacean not related to true lice, which are insects.
Photos:   Courtesy of Niklas Gustavsson (beautifully clear image of fish louse out of water!)	Courtesy of Niklas Gustavsson	Courtesy of Qian Hu Inc.	Courtesy of The Aquatic Animal Health Research Institute
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TRUE WORM PARASITES (TREMATODES, NEMATODES, CESTODES)

Common Name:	Roundworms
Pathogen/Cause:	Unknown nematode species (metacercarean form)
Physical Signs:	As shown below as an infection of connective tissue (usually internal worm infections cannot be seen externally and often affect the gut; in these cases, they have migrated to muscle tissue).
Behavioral Signs:	Loss of appetite, lethargy, etc.
Potential Treatment:	Try Clout or an antiparastic medication for large parasites (formalin and many methods were tried on the first cases below without success). There is also some good information on the treatment of camallanus worms as contributed by Jason Parry.
Other Notes:	Please read my article, Worms in my tank?? before jumping to the conclusion that any worm in the tank is a parasitic or disease causing worm. The large majority of small worms seen in the aquarium not attached to the fish are free-living and harmless (the ones shown below are an obvious exception). Most of these true parasites shown below require a fish host at some time in their life cycle. They often come in with contaminated live foods such as Tubifex worms.
Photos:   Courtesy of Mike Spafford (unknown/possible sparganosis of nematode infection attacking muscular tissue)	Courtesy of Mike Spafford (unknown/possible sparganosis of nematode infection attacking muscular tissue)	Courtesy of Tom Lorenz	Courtesy of Kevin Piper (another unpleasant photo of camallanus worms protruding from a fish)
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Courtesy of Averi Dohr	Courtesy of Anonymous (an interesting photo sent to me; moving nematode was found between the scales of a large koi)
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MISCELLANEOUS AILMENTS

Common Name:	NA / Unidentified Lesions, Growths & Cysts
Pathogen/Cause:	Unknown--those shown below could have a number of causes--they could be bacterial infections that formed pus-filled cysts under the skin, they could be true tumors (see above), Lymphocystis, cysts that formed around worms, etc. Because I was uncertain, I didn't want to mislabel them, so I keep them here in the hopes that they will still help someone, if they see something similar. For a more thorough discussion of various causative organisms, please refer to Dan's archived comments on "unknown lumps & bumps".
Physical Signs:	Varies greatly.
Behavioral Signs:	Varies greatly. May have no affect on behavior at all, depending on cause. If near the mouth and it hinders eating, could have obviously faster consequences.
Potential Treatment:	Unknown, may be incurable in some (if they turn out to be true tumors); depends on individual case. For those exuding pus and fluid and/or those cases where behavioral lethargy and malaise is seen, try an antibiotic. More detailed information on different treatment options that can be attempted can be found in Dan's archived comments on "unknown lumps & bumps".
Other Notes:	These pictures shown below may span a wide range of different causes. Some are clearer than others.
Photos:   Courtesy of Mike Spafford (case shown above is recurrent; suspect lympho, but without certainty)	Courtesy of Yew Wee Tan (this didn't look like any classic "textbook presentation" of anything that I knew of, except possibly a clumping bacterial or fungal nidus on the trailing caudal fins; photo clarity didn't permit me to say for sure... if anyone has any idea of this being more specifically characteristic of something else, please let me know)	Courtesy of Michele Hartley (beautiful photo of a true hollow cyst; I believe that it may have originated with a bacterial infection just under the skin, and then grown enormously due to pus accumulation; fish shown above died within a relatively short time of first appearence)	Courtesy of Luigino Bracci (amazingly clear photos of such a small, darting fish; it is beyond my knowledge what this growth could be, it was described to me as an adherant circumscribed and object that the owner believed may have been a parasite; however, it is larger than and distinct from most of the common fish parasites I am aware of)
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	Courtesy of Nick Austin(beautiful series of 3 professional-quality photos; appear to identify the same multiloculated, fluid-filled cyst)
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OTHER

Photos:   Courtesy of Michele Hartley (illustrates fight injury in male bettas that jumped barrier)	Courtesy of Michele Hartley (illustrates fight injury in male bettas that jumped barrier)	Courtesy of Kamphol (shows a normal gravid loach [the equivilent of "pregnant" for egglayers]--obviously not a disease state, used here only for the purposes of comparison with pathologic causes of bloating)	Courtesy of Nathan Cantrell (superficial skin injury secondary to trauma; likely at this point not yet seriously infected, but may be in a subacute time frame)
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