What To Do If There Are Spots On The Fish

First of all, make sure that these spots are not a variant of the normal coloring of the fish. Sometimes these marks are present only in fish of the same sex or appear during periods of maturation or sexual activity. However, there are many abnormal spots that can affect the condition of the fish. There are so many of them that we grouped them by color so that it would be easier to refer to them. Started with light spots, among which there are those that occur most often, namely white spots.

White or light spots

  • White spots the size of a pinhead on a fish’s head, body and fins are most likely the disease described in section 4.1.23. Lymphocystis cysts are less likely to occur (section 3.1.3). They are even less likely to be caused by a protozoan parasite called Apisoma (section 4.1.1).
  • Tiny whitish spots on fins are usually the smallest wounds, but sometimes they can look like white spots described in the previous paragraph. Newly acquired fish that have such spots should be kept under observation.
  • Whitish spots, which, on closer inspection, turn out to be tiny tufts protruding from under the edges of the scales, may result from the destruction of the fish organism by a fungus (sections 3.3, 3.3.8).
  • Small whitish tufts, especially on hard tissues (fins, gill covers), can be Epistylis (section 4.1.5).
  • Small whitish patches in fish from the family of the pets may mean “guppy disease” (section 4.1.6).
  • Whitish circles are probably wounds caused by leeches (section 4.2.6).
  • A white spot, due to which the lens of the eye becomes opaque, may be caused by eye trematodes (section 4.2.5). See also cornea clouding of the eyes (section 6.2) and the section “What to do if. , № 5.
  • Gray-white subcutaneous spots of irregular shape, which are usually found in tetras (but also in some other fish) most likely indicate neon disease (section 4.1.13).
  • Grayish or whitish spots of irregular shape are most likely caused by excessive formation of mucus (see the section “What to do if.”, No. 19).
  • Gray spots on the scalar Pterophyllum spp. may be caused by Metrosporis parasites (section 4.1.8).

Note. During spawning, males of some genera of the carp family (for example, barbs) appear white spots (tubercles) around the gills or head, and sometimes at the base of the pectoral fins. This is quite normal and not a cause for concern.

Black or dark spots.

  • Black spots on the body or fins are usually a manifestation of a disease called “black spots” (section 4.2.2).
  • Black or dark spots around the mouth of East African cichlids is a disease called “black chin” (section 1.2.4).
  • Dark or colorless irregular-shaped spots on the body can be superficial injuries (section 1.6.1), including burns.

Red spots

  • Red spots on the skin can be wounds caused by large external parasites (ectoparasites), section 4.2, or subcutaneous hemorrhages resulting from a systemic infection (sections 3.1, 3.2).
  • Red spots or stripes on the fins (fin stagnation) are often a sign of incipient fin rot (section 3.2.2).

Spots of other colors

  • Tiny yellow-green spots, sometimes present on the body of a fish in such a huge amount that it seems as if it is completely covered with this color, is a sign of oodinium (section 4.1.22).
  • Tumors (section 6.7) may initially look like spots. They come in all sizes and colors and are found anywhere on the body. (See the section “What to do if.”, No. 13).


When diagnosing one of the many different types of white or light spots, it is especially important, in particular, a new one is a fish or has long been living with you. It should be noted whether other signs of the disease are present — for example, fish with white spots itches, but fish affected by lymphocytosis do not. It is important that the species to which the fish belongs (for example, tsikhlovye and konzubyvye do not get sick guppy or neon disease!), As well as the development and infectiousness of the disease (ichthyophthyriosis develops quickly, and others much slower). These differences are discussed in the relevant sections of Chapter 21.

What if the fish have a tumor

Cones, tumors, or tumors on the surface of the body come in all sorts of types, shapes, sizes and colors. The range of possible causes is equally wide.

  • Protruding bumps (tissue damage) can occur as a result of some bacterial infections (section 3.2). for example, fish tuberculosis (3.2.3). These tubercles may have a white or pale necrotic area (sometimes with an ulcer fossa) and a region of redness (hemorrhage).
  • Obstruction of the digestive tract (including constipation (section 2.1)) sometimes causes a one-sided bulge, usually on the side or abdomen.
  • An internal tumor (section 6. 7) can also cause a similar bulge. An external tumor can appear literally anywhere on the head or on the body of the fish. External tumors may be the same color as the surrounding skin, but sometimes they are black (melanoma). They come in all sizes and shapes, and appear in clusters as well as one at a time.
  • Smallpox fish (section 3.1.2) initially causes the appearance of grayish or whitish spots of irregular shape, resembling spots caused by excessive formation of mucus. Initially, these spots are soft, but over time they harden and, by their consistency, become similar to wax. In tropical fish, this disease is very rare.
  • The encapsulated helminth larvae (sections 4.0, 4.2.2) under the skin may look like small tumors on the body. Such larvae can be several or only one. They can have shades from light gray to dark gray if the fish itself is light.
  • Whitish neoplasms, usually forming clusters, in appearance resembling a bunch of grapes or cauliflower, and especially noticeable on the fins, are manifestations of lymphocystic cysts (section 3.1.1). (See the section “What to do if.”, No. 12). Note: In some fish (especially in males of the cichl family), when they become adults, large fatty growths (occipital humps) grow on the forehead. Sometimes these growths become permanent, and sometimes they decrease or disappear when the fish do not participate in spawning. For mature females, it is quite natural if one ovary is more developed than the other, and forms an asymmetrical bulge on the body.
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Tumors are more common in older fish. To distinguish the tubercle formed by the internal tumor from the tubercle caused by the obstruction of the digestive tract, find out whether the fish excretes excrement and eats it (both are unlikely in case of severe obstruction). A tubercle formed by an internal tumor will develop more slowly.

What if the fish is too thin

Weight loss and exhaustion can occur as a result of a number of reasons.

  • Direct pathogenic effects of the disease. Examples:

– pathogenic infection (usually systemic) caused by bacteria (section 3.2) or fungi (section 3.3). It happens rarely. Much more often causes depletion of fish tuberculosis (section 3.2.3).

– an infection caused by protozoan endoparasites. for example, neon disease (section 4.1.13) (it occurs in tetras and some cyprinids);

a disease associated with the formation of holes in the head (section 4.1.10) in tsikhlovye; Heterosporis (section 4.1.8) of the scalar Pterophyllum spp.

  • The side effect of almost all illnesses is that the fish do not eat, because they are sick, and they are gradually exhausted.
  • Severe infection with endoparasitic worms (sections 4.2.3, 4.2.4, 4.2.10, 4.2.12, 4.2.13) can also lead to exhaustion (because the parasites feed on their host’s food). At the same time abdominal distention due to the huge mass of worms in the intestine can be observed. Some worms damage the intestinal lining and thereby affect nutrient intake.
  • Improper nutrition or prolonged inadequate food intake, sections 2.0, 2.4 (see Chapter 7).
  • Fish that stop eating when they care for their offspring (for example, incubating eggs and fry in the mouth) can become very depleted during this time.
  • Spawning or childbirth can cause a female to become thin. (See the section “What to do if.”, No. 6).


“Too thin fish” is a very relative concept. Most of the fish that have lived for some time in the home aquarium are more likely to be more well-fed than it was provided for by nature. The fact that a fish is thinner than others and has a flat belly profile does not necessarily mean that it is unhealthy in some respects. This should not deter the aquarist and keep him from buying such fish. Real exhaustion (concave abdominal profile) is another matter. It does indicate poor health and inadequate food intake. If a fish that has long been living in an aquarium suddenly begins to lose weight, this should be a cause for concern. Exceptions are cases where her diet or diet has been deliberately reduced because she is too well fed, or when she recently put off eggs, or gave birth, or incubates eggs in her mouth.

What to do if fish are stunted

Growth retardation — either constant (the fish have not yet reached their normal size), or temporary (the fish grows slowly or for a while ceases to grow at all) is a fairly common phenomenon. Some types of growth retardation (for example, a genetic defect) cannot be cured, while others can be cured if the problem that caused the delay is resolved. The sooner this problem is solved, the higher the chance of avoiding permanent growth retardation. The following are possible causes of stunting.

  • A genetic defect (section 5.0), sometimes associated with closely related crossing. Treatment can not be.
  • Malnutrition (sections 1.2.2, 2.4, 2.5) or insufficient feeding (section 2.4). See chapter 7.
  • Lack of appetite. see the section “What to do if. ", № 6.
  • Direct biochemical effects of adverse water parameters (sections 1.1, 1.2, 1.3).
  • The direct result of a disease caused by pathogenic organisms (section 3.0).
  • The direct result of infection by some parasites. for example, leeches (section 4.2.6) or intestinal worms (sections 4.2.10, 4.2.12, 4.2.13).
  • Insufficient living space. the aquarium is overpopulated or too small for this particular fish.
  • Hormones that inhibit growth. Studies have shown that there are few species of fish (however, further studies may show that in fact there are much more such species), in which the dominant (largest) individual in the brood produces hormones that suppress the growth of other fish. These hormones act only in close proximity and restrain the growth of potential competitors of this individual. brothers and sisters. But the fish that are in the same home aquarium, even in the largest, can be considered to be in close proximity!
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Remember that in some fish species of the same sex may be larger than the other, and this is completely normal. There are fish whose growth rate is regulated by other factors. Such dimorphism appears at an early stage and may become more pronounced over time, as larger fish compete more successfully for food. Meanwhile, smaller fish often experience stress and loss of appetite and because of this they grow even slower. As a result, large fish devour smaller ones. Therefore, young fish of some species must be regularly sorted by size and grown separately. When you reject individuals from each brood, it is important to remember about the possibility of early manifestation of sexual dimorphism in size. Although the rejection of explicit "dwarfs" is a useful thing, but if the entire rejection is carried out only in size, the case may end up being left with representatives of only one sex.

  • Overly frequent reproduction. This applies mainly to females, which direct a significant amount of energy to the formation of caviar. Females incubating the eggs in the mouth can suffer greatly because they do not eat at all at this time. Males of fish of those species that incubate caviar and fry in the mouth (both parents or father do this) may also suffer during this period. Other types of care for offspring can also badly affect the parent (s) guarding the eggs or fry. They can not simultaneously fully take care of the offspring and get food.
What To Do If There Are Spots On The Fish

What to do if the fish has changed color

A color change in a fish is sometimes indicative of a change in its health or in the status it has in an aquarium (it can also affect its health). Fish that have noticeably darkened (or, on the contrary, brightened) may well suffer from stress or illness. An abnormally bright color can also mean a problem.

Unexpected or abnormal discoloration should always be considered suspicious if they are accompanied by other common signs of illness.

The following discoloration may be signs of specific diseases.

What To Do If There Are Spots On The Fish
  • If the fish is blind, it may become resistant to a solid dark color. Perhaps this is because the fish perceives the environment as a solid darkness and therefore seeks to conform to it (in order to disguise).
  • An abnormally dark color is a very common symptom of stress (section 1.5.2), but other than that it can be observed during many other diseases. It may reflect physiological changes or an attempt by a sick fish to become imperceptible (a natural means of protection from predators and conflicts with other fish).
  • An asymmetric dark area on one side — usually on the lateral side of the head — may be the result of localized nerve damage that suppresses control of the melanophores. Possible causes are a burn or mechanical injury (section 1.6.1), a localized bacterial infection (section 3.2) (for example, an abscess) or a tumor (section 6.7). Persistent damage may cause permanent discoloration.
  • Dark or discolored spots may result from burns or other superficial injuries (section 1.6. 1). for example, bruises.
  • Black spots that expand over time (this occurs over several days or weeks) are probably melanomas (section 6.7).
  • In cichlids, dark areas around the mouth are a disease called “black chin” (section 1.2.5).
  • In the Characin (less often in some Cyprinidae), blanching of the color is sometimes accompanied by the appearance of whitish or grayish spots under the skin. this is a sign of neon disease (section 4.1.13).
  • Abnormally pale coloration may, among other things, mean fish tuberculosis (section 3.2.3); shock (section 1.5.1); osmotic stress (sections 1.1.2, 1.6.2).
  • Gray color (either whole body or single spots) can mean excessive production of mucus, which is a reaction to irritation caused by adverse environmental conditions (section 1.0) or parasites (section 4.0). In addition, it can be a disease manifested as excessive formation of skin mucus (section 4.1.18).
  • A yellowish tint may be a sign of oodinimosis (section 4.1.22).
  • Reddened areas can result from damage caused by external parasites (section 4.1); injuries (section 1.6.1); irritations caused by acidosis or alkalosis (section 1.1.1), as well as ammonia (section 1.2.3); inflammation or hemorrhage as a result of systemic bacterial (section 3.2) or viral (section 3.1) infection; vitamin C deficiency (section 2.5).
  • Vast abdomen areas with a pale pink color are associated with dropsy (section 6.3) and some other systemic bacterial (section 3.2) or viral (section 3.1) infections.
  • The discoloration of the fins (including the tail), along with symptoms such as lightened, grayish-white, frayed edges, reddened due to inflammation (reddening may not be), red stripes on the affected fin (fins) may mean fin rot (section 3.2.2).
  • Too bright or any other abnormal color can be a sign of damage to the central nervous system, as a result of which control over chromatophores is lost. Possible causes are hypoxia (section 1.3.3), poisoning (section 1.2.1), acidosis or alkalosis (section 1.1.1), injury (section 1.6.1), or a tumor (section 6.7).
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In order to assess how important a color change is, it is important to know what normal color changes a fish of this type can show. In many fish, the color is relatively constant, so any significant deviations should be cause for concern. However, in some fish, the color changes during their development and puberty. At the same time, there are fish that use the color change as a means of communication and with its help demonstrate, among other things, their mood, social status, sexual status or courtship. The decoration and lighting of the aquarium can also play a role, as some fish become darker or, on the contrary, paler, trying to match their surroundings.

What to do if a cotton-like substance appears on the fish

Neoplasms resembling cotton wool in appearance are usually a fungus, or a cotton disease (section 3.3.3). Similar tumors occur in a bacterial disease that is caused by the oral fungus Columnaris (section 3.2.4). Usually, the fungus infects the mouth area, but it can attack other parts of the fish’s body as well as fins and gills.

What to do if a fish has holes

In addition to the mouth, gill slits and anus, fish have many other completely normal and natural holes. This, in particular, the nostrils that are on the face. Some fish have only one pair of nostrils, others have two pairs. In addition, fish have sensitive pores. These are tiny holes scattered on the head. There are one or more rows of the same holes. they go to the sides of the body and sometimes stretch to the very tail.

"Problem" holes.

  • In cichlum, sensitive pores on the head and on the lateral line (rarely) can grow and become infected due to a disease called hole (section 4.1.10).
  • If the representatives of the Cichlovian family have enlarged or corroded pores, but there are no signs of pus in them, this may be due to old age. There is no evidence that such pores cause any harm.
  • Holes on the fins or on the body are usually injuries (section 1.6.1). The openings on the body can be wounds that are left behind by external parasites. such as the Lernaea crustaceans (section 4.2.1), leeches (section 4.2.6) or fish lice (section 4.2.7).


Aquarists who keep cichlids and have never seen the manifestations of the disease associated with the formation of holes in their heads, are aware of the threat this disease poses to their fish. They see the nostrils and perfectly healthy sensitive pores and imagine that these are the first signs of this terrible disease. To avoid unnecessary stress for the aquarist and the senseless treatment of healthy fish, we strongly recommend that every newcomer who holds a cichlid and is worried about their disease, do the following. Let him ask a more experienced colleague to find and show him as a reference the normal holes that should be on the head of all cichlids.

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