Specific signs of fish diseases.
Continued…
If the fish has ulcers, bumps, and tumors.
Tumors are more common in older fish. Tumors may initially appear as spots. Bumps and tumors come in all kinds of types, shapes, sizes, and colors. The range of possible causes is equally wide. They can occur anywhere on the body. Melanosarcoma (a tumor of pigment cells, a malignant tumor) is easily recognized by its black color, which quickly spreads throughout the fish’s body. Other tumors are not accompanied by pathogenic symptoms.
An internal tumor causes a unilateral bulge, usually on the side or belly. An external tumor can appear anywhere on the body. An internal tumor develops more slowly. Sometimes a tumor is so large that it bloats the fish’s body. If the tumor is small and affects internal organs, it can only be detected upon dissection. Helminth larvae under the skin may look like small bumps on the body. They can range in shade from light gray to dark gray.
• Protruding tubercles with a white or pale necrotic area, sometimes with an ulcerous pit and an area of redness (tissue damage), open ulcers appear as a result of bacterial infections — Tuberculosis.
• Tiny whitish tumors, usually forming clusters resembling a bunch or raspberry and especially noticeable on the fins. Initially looks as if the body is sprinkled with semolina, then hard spherical cysts (0.5-1 mm) — Lymphocystis.
• Whitish lump-like tumors, protrusions on various parts of the body — Glugeosis.
• Oval, spherical, hemispherical nodules of porcelain-white or yellowish color, ranging in size from a poppy seed to a pinhead, form on the gills and skin of fish — Nodular disease.
• Grayish-white tumor growths, ranging in size from a millet to a lentil seed on the fins, in the opercular area and along the edges of the mouth opening. The number, size, and appearance of the tumors vary considerably. This is a proliferation of the skin layer leading to the formation of pedunculated tumors — Papillomas.
• Fish pox — initially causes grayish or whitish irregular spots 2 to 10 mm in size, formed due to excessive mucus production. Initially, these spots are soft, but over time they harden and become wax-like in consistency. Neoplasms caused by fish pox differ from spots appearing in cases of excessive mucus production in that they rise above the body surface and have well-defined edges. This disease is very rare in tropical fish.
• Holes on the fins or body are usually — Injuries. Holes on the body may represent wounds left behind by external parasites – crustaceans — Lernaeosis, Argulosis, Leeches.
• The presence of large growths on the lips can lead to a tumor or cyst closing the oral cavity or mouth opening, causing fish to starve and die from exhaustion — Lymphocystis.
• Encapsulated helminth larvae under the skin can look like small growths on the body. There may be several such larvae or just one. They can range from light gray to dark gray if the fish itself is light-colored.
• Raised scales, bumpy elevations, ulcers, dead areas on the body and fins, darkening of the fish’s coloration, emaciation — Ichthyosporidiosis.
• Small dark spots turning into regular rounded reddish ulcers, causing skin inflammation, redness of individual areas with the formation of boils, lump-like ulcers up to 2 cm in size — Furunculosis.
• Reddened areas or spots can be the result of damage caused by — External parasites, Injury, Alkalosis, inflammation or hemorrhage as a result of a systemic bacterial or viral infection, Vitamin C deficiency.
• Blood-red spots of various sizes and shapes turning into ulcers, reddish, bleeding inflammations — Aeromoniasis, Nodular disease, Glugeosis, Philometrosis, Vibriosis.
• The appearance of erosions and small reddish ulcers on the body — Gyrodactylosis, Ichthyosporidiosis.
• Ulcers form at the bases of destroyed fins, and the spinal column is exposed — Fin rot.
• Whitish circles, rounded bloody inflamed areas 3-8 mm in size – these are likely wounds inflicted by — Leeches.
• Red spots on the skin can be wounds caused by large external ectoparasites Lernaeosis, Argulosis, subcutaneous hemorrhages from a systemic viral and bacterial infection.
• Ulcers with bright red edges, scales raised at the ulcer sites — Argulosis, Lernaeosis.
If the fish is bloated.
There are several possible reasons why a fish might have an abnormally swollen body or bloated belly, which is often a secondary symptom of a number of diseases. The abdomen may swell in females if they are pregnant or carrying eggs. If the bloating develops gradually, over time, almost imperceptibly, it is in most cases either obesity, tapeworms, or a tumor (the latter most commonly appearing in older fish).
Bloating caused by tapeworms is unilateral only and can cause the fish to swim on its side. An internal tumor, like dropsy, causes scale protrusion, but only on one side. If the swelling develops slowly, it is either — Obesity, Tapeworms, or (in older fish) a Tumor. Note that the fermentation process caused by bacteria produces gas, and this can cause bloating after the fish’s death. Such post-mortem bloating cannot be considered an indicator of the cause of death.
• Sudden bloating caused by pathogens — Aeromoniasis, Vibriosis, False neon disease, Tuberculosis, Triaenophorosis, Spironucleosis, Furunculosis, Sanguinicolosis.
• Abdominal swelling due to a huge mass of worms in the intestine — Severe worm infestation.
• Enlargement of the front part of the abdomen — Caryophylleasis.
• Bloating accompanied by raised scales that make the fish look like a pinecone, popeye — Dropsy, Swim bladder inflammation.
• Malawi bloat is caused by pathogens or environmental problems. It affects only mouthbrooding East African cichlids.
• The fish recently ate a large piece of food. Some carnivorous and predatory fish consume fairly large pieces that last them for several days, during which their belly slowly shrinks to normal size and shape. Fish that feed continuously in small portions should not be fed a large amount of food at once – otherwise, their belly will bloat, and digestive disorders will follow after a while.
• Abdominal swelling usually resulting from prolonged feeding of fish with inappropriate food — Obesity.
The fish has a distorted body shape.
Some fish have a deformed skeleton as a result of a genetic mutation. If the deformation is minor, it is not always noticeable. Some fish change shape as they grow. Some develop body deformation as part of their “spawning dress”. Among such deformations, the so-called “nuchal hump” is particularly well known – a fatty growth in the forehead area that appears in males of certain cichlid species when they become adults or participate in spawning (females have it too, but less frequently). Excluding obesity, body shape distortion in an adult fish is most likely the result of a disease caused by pathogens or parasites.
• Such deformation can occur as a result of — Injury, Fish tuberculosis, infection with certain types of external parasites, unfavorable water parameters, vitamin deficiencies.
• The spinal column is curved — Ichthyosporidiosis, Plistophorosis, Tuberculosis, False neon disease, Diplostomiasis, Postodiplostomiasis, Camallanosis.
• A tumor can make the fish appear deformed (such a phenomenon is relatively rare).
• Poor nutrition can cause the belly to become concave, while overfeeding or an inappropriate diet can, conversely, lead to obesity. This type of body shape distortion is perhaps the most common.
• Deformity. Some fish have been specifically selectively bred to produce artificial forms. Some of them have a bloated or unnaturally round belly.
If the condition of the gills has changed.
The fish’s mouth usually opens and closes slightly in time with the movements of the gill covers. In most fish, the mouth should not remain constantly open. Both gill covers should be intact and cover the gill filaments. They are hard to see when the fish is healthy because the gill covers lift only slightly and slowly during each respiratory movement. The gill filaments should be red, not swollen, and not prevent the gill covers from closing properly.
Increased gill movement combined with labored breathing, frequent surfacing, and gasping for air is a sign of respiratory distress. This indicates a problem with oxygen levels in the aquarium or that the fish is having a harder time consuming oxygen than usual (e.g., due to gill damage). Ammonia, nitrite, and nitrate levels in the water should be checked, as these substances are usually the cause of this problem. If the gills look abnormal:
• Slowed or stopped movement of the gill covers — Hypothermia.
• Visible to the naked eye, white worm-like parasites 0.5-2 mm in size on the gill filaments — Ergasilosis.
• Gill damage or irritation caused by — Parasites, Poisoning, Sifting sharp-edged substrate.
• Gills become pale and covered with mucus, impairing respiration and gas exchange, causing fish to surface and gasp for air — Tuberculosis, Costiosis, Gyrodactylosis, Trichodiniosis, Chilodonellosis.
• Gills are covered with a thick layer of mucus, their color fades due to anemia and becomes mosaic-like. Adjacent gill lamellae fuse together — Dactylogyrosis, Sanguinicolosis.
• Grayish-white mucous coating extending from the gill slit – Poisoning, Gill parasites, Alkalosis, Costiosis, Gyrodactylosis.
• Gills are inflamed, swollen, colored yellow-red or whitish-yellow — Bacterial gill disease.
• Dark red and light specks and spots. Point hemorrhages are noted on the gill filaments — Branchiomycosis, Bacterial gill disease.
• Dark or milky-white spots — iron deposits during Acidosis.
• Gills acquire an unusual bright red color — Cryptobiosis.
• Brownish gill color — Nitrite poisoning.
• Black spots on the gills — Diplostomiasis.
• Gill covers are deformed, flaring gill covers, gills protruding from under the gill cover — Bacterial gill disease, Branchiomycosis, Ergasilosis, Costiosis, Nodular disease.
• Erosion, swelling, and death of gill tissues — Branchiomycosis, Bacterial gill disease, Tuberculosis, Tetrahymenosis, Sanguinicolosis.
• Inflammation of the gills, then bleeding with clot formation between gill lamellae, fish respiration becomes labored. Alternation of bright red and white areas on the gills, various deposits, hemorrhages, adhesion, and necrosis of gill lamellae — Ichthyophthiriasis.
• Injury (rare).
If the condition of the eyes has changed.
Eyes serve as an indicator of health status. Both eyes should be of equal size, clear, not cloudy, and not protruding forward. They should be alert and responsive to stimuli rather than staring blankly into space.
• Corneal clouding of the eye can be — Eye flukes, Bacterial or fungal infection, Chlorine damage, Gas bubble disease.
• A white spot making the eye lens opaque can be caused by — Eye flukes, Sanguinicolosis, Saprolegniasis, Diplostomiasis.
• Popeye (a secondary symptom for a number of diseases) – protrusion of the eyeball, a major cause for concern and can be caused by — Poisoning, gill parasite infestation, severe hypothermia, Glugeosis, Ichthyosporidiosis, Dropsy, Aeromoniasis, Pseudomoniasis, Furunculosis, Tuberculosis, Sanguinicolosis, Vibriosis, Columnaris.
• If a fish is blind, it may acquire a persistent solid dark coloration.
The fish has developed holes.
In addition to the mouth, gill slits, and anus, a fish has many other completely normal and natural openings. In addition, fish have sensory pores. These are tiny openings scattered across the head. There is another row or several rows of similar openings running along the sides of the body and sometimes extending all the way to the tail. Aquarists who keep cichlids and have never seen manifestations of hole-in-the-head disease are well aware of the threat this disease poses to their fish. “Problem” holes:
• In cichlids, sensory pores on the head and lateral line (rarely) can enlarge and become infected due to disease. Quite deep holes can appear in the skin ranging from less than 1 mm to 1 cm in diameter. Affected pores usually fill with whitish pus, which in severe cases even leaks out. The skin does not rupture immediately: this is preceded by swelling and a “whitening from within” of a small area; within 2–3 days, the formation tightens into a pointed cone with a white head, then the skin ruptures and decomposed cartilage emerges as a thick white mass — Hexamitiasis.
• If pores in cichlids are enlarged or eroded but show no signs of pus, this may be a consequence of old age. There is no evidence that such pores cause any harm.
• Holes on the fins or body are usually — Injuries. Holes on the body may represent wounds left behind by external parasites – crustaceans — Lernaeosis, Argulosis, Leeches.
If worms or other animals are attached to the fish.
These are large parasites visible to the naked eye as individual animals. It is usually not difficult to determine what type they belong to. The presence of any of these parasites in a home aquarium is most likely due to the use of live foods or wild-caught decorative items. But even in such cases, these parasites are rarely seen.
• White rod-like formations on the fins, elongated Y-shaped parasites attaching to the fish at the base of the Y — Lernaea crustaceans (Lernaeosis).
• Translucent saucer-shaped parasites with clearly visible black eyes dotting the fish’s skin and fins in abundance — the fish louse Argulus (Argulosis).
• Whitish larvae, worm-like parasites 0.5-2 mm in size on the gill filaments, visible to the naked eye — Ergasilus larvae (Ergasilosis).
• Small mobile worms on the skin, visible to the naked eye — Gyrodactylosis.
• A worm-like parasite usually attaching to the fish at both ends or moving along its body in looping motions — the fish leech Piscicola.
• Ulcers with bright red edges, scales raised at the ulcer sites — Argulosis, Lernaeosis.
• If worms are hanging from the fish’s anus, they are Camallanus worms (Camallanosis).
If the fish has abnormal feces.
The color and consistency of fish feces can vary depending on diet and, to some extent, fish species. Normal feces are usually brownish or greenish. They have a fairly uniform diameter typical for the fish. Soon after emerging from the vent, they detach, although sometimes fish push out a few centimeters of feces before they break off. If a change in the appearance of feces can be linked to a change in diet, there is no cause for concern. Abnormal feces should be regarded as suspicious if it is a persistent phenomenon.
• Irregularly shaped feces often indicate a digestion or diet problem.
• Transparent-whitish, often thread-like and stringy mucous feces – a characteristic sign of — Hexamitiasis.
• Feces with alternating dark and light segments can indicate parasite infection — Capillaria (Capillaria worms). Found in the intestines of various fish. Adult worms shed eggs along with fish feces. Treatment requires a special deworming medication such as Fenbendazole, Levamisole, or Piperazine. Depending on the chosen medication, the dewormer is either mixed into the fish food or added to the aquarium water.
• Bubbles in feces likely indicate digestive upset. This is usually a short-term phenomenon observed in individual fish that disappears very quickly. However, if this happens every time the fish are fed a specific food, it is best to exclude that food from the affected fish’s diet.
• The absence of feces for a noticeable period can indicate constipation. Of course, this will also be the case if the fish is not eating anything.
• The anal opening swells and turns red — Aeromoniasis, Dropsy, Enteritis, Hexamitiasis.
• Sometimes part of the intestine hangs from the anal opening — Dropsy, Hexamitiasis.
