Over the course of time, when keeping an aquarium everyone will sooner or later have to face a disease or husbandry problem with one of their fish or invertebrates. The aquarist is faced with two tasks when this occurs: recognizing the problem and making diagnosis and treatment choices. In this article I will describe some of the more common symptoms and diseases to watch for in both fish and commonly kept invertebrates. My goal is to help you learn how to spot problems before they advance to the point of no return. After learning to spot problems, your next task is to determine a reasonable course of action. Often, this means enlisting the advice of your Local Fish Store (LFS), fellow hobbyists and people on internet message boards.

Observable symptoms come in two forms: changes in appearance and behavioral changes. Any rapid changes in either are cause for concern. Some parasites are visible to the human eye, or leave marks or raised areas that are readily apparent to the observant aquarist. In fish, these can appear as definite and well-defined spots, dusty or powder-like coverings, a cloudy slime coat, large obvious bug-like critters or small and slightly raised translucent bumps. Bacterial infections, mostly as secondary infections to a parasite or an injury, often show as receeding fins (fin rot), blood streaks in the fins or cloudy areas on the fish. In some less apparent problems, the symptoms in fish can be noted as changes in behavior, such as clamped fins and altered breathing rates.

Since some fish diseases are relatively common, I will give you a summary of some of the more common ones and their typical symptoms. The most common problems involve parasites, with bacterial infections being most common as secondary infections due to parasites or physical damage resulting from an attack by another fish. The most common parasite is the protozoan Cryptocaryon irritans, known as marine ick. This parasite typically manifests itself as small pinhead size white spots on the fish's body. As the gills are generally the first sites of infection, the fish also often shows an increased breathing rate. Flashing, or scratching on the rocks and/or sand, is often exhibited due to several parasites. With ick, flashing can often precede any visible spots on the fish. Amyloodinium ocellatum, or velvet, is the second most common parasite, and often the most deadly. Symptoms start out as rapid breathing and flashing and are followed by a dust-like covering. Sadly, by the time most hobbyists recognize the problem, usually when the dust-like covering appears, it is often too late for the fish. Flukes are transparent leech-like parasites that are often found infecting the gills, again causing rapid breathing, or swelling of the skin and eyes. When on the skin or eyes they show as slightly raised clear bumps on the fish, sometimes with a noticeable undulating movement. Wild-caught clownfish often come down with Brooklynella. This shows as thickened white areas of the slime coat in its beginning stages. Uronema is most prevalent in butterflyfish and is evident by raised scales and redness around the raised scales.

The two most common bacterial problems in fish are "pop eye" and "cloudy eyes," often occurring together. These two are typically secondary infections to an injury, either from shipping or fighting. Angels, in particular, seem to contract eye infections due to collection techniques or transportation problems. Fin rot is evident when the fins show degeneration and start to look ragged in appearance. The most common cause of fin rot is physical abuse, followed closely by poor water quality. The other frequently seen bacterial problem is hemorrhagic septicemia, a scientific term for a systemic infection causing a breakdown of the blood vessels. Reddened patches and streaks of blood in the body and fins is the outward appearance typically associated with this disease. Often, the cause is poor water quality, and in some cases, a secondary infection resulting from an advanced parasite infestation is indicated.

Problems with invertebrates such as corals and shrimps can be more difficult to detect and treat, especially if they are disease related. Sadly, invertebrate pathology is poorly studied, although people such as Eric Borneman are doing some work on coral diseases. Invertebrate problems can stem from water quality issues, poor handling in the supply chain, aggression between animals, inadequate lighting or water motion. Lack of polyp expansion in corals typically comes from inadequate water motion, lighting or water quality problems. Bleaching, the expulsion of the zooxanthellae, is often the result of lighting problems or temperature stresses. Tissue recession in corals can be either a slow phenomena or very rapid as is observed with Rapid Tissue Necrosis (RTN) in small-polyped corals. Causes are still hotly debated, but in my experience, may range from physical damage, chemical warfare and light shock, and temperature stress, to insufficient water changes. Crustaceans (crabs and shrimps) exhibit problems by loosing limbs during shedding and general lethargic behavior. Water quality problems, such as imbalances of trace elements and dietary problems, are often at fault here. In newly acquired specimens, close attention should be paid to acclimation procedures, as rapid shifts in salinity can often cause problems that won't show up until the first molt when your newly acquired Coral Banded Shrimp looses both claws. Echinoderms (sea urchins, starfish, and cucumbers) also require careful attention to acclimation and may take several days to manifest problems. Generally, problems in echinoderms appear as a loss of spines, limbs or feeding apparatus (in cucumbers). Many filter-feeding echinoderms such as cucumbers and crinoids will simply wither and die due to a lack of proper food. In the case of filter-feeding sea cucumbers their death can spell disaster for your entire tank as they may release toxins when they die. Unless you are well versed in the food requirements of filter-feeding echinoderms and have an established source of the right foods, I would strongly recommend avoiding this group of animals.

When it comes to obtaining help, there are several resources available to the hobbyist. The first source is a good set of reference books on aquarium keeping, both those concerning general aquarium husbandry as well as those that are more specific about the species you like to keep. Here's a list off my shelf (Noga's book is still on the wish list though) in no particular order:

These should be just as important to purchase as the tank itself, since many problems can be avoided with some simple research and planning. However, there will still be times when your personal reference library doesn't contain an answer. If you are fortunate enough to have a knowledgeable pet shop in the area this is a good starting point, especially if they know you and are familiar with your set up. Another good source of help is other hobbyists. Membership in the local aquarium society is a great way to get to know other hobbyists and build a friendly local support network. Last, but not least, is the online world of message boards such as Reef Central, of course. Often, the message boards can give you rapid access to people with diverse backgrounds in the hobby and the industry. Online help can often come from researchers, aquaculturists, shop owners, and dedicated hobbyists with tons of good insight and information. The Reef Central message board has forums dedicated to disease and fish husbandry as well as the general forums and specialty forums on invertebrates (Dr. Ron Shimek's forum) and coral husbandry (Eric Borneman's forum). If you are new to the message board, it will be worthwhile to spend some time "lurking" to get a feel for which poster's are respected and generally are trusted to give good advice. This will allow you to sort the good information from the bad when the time comes for you to seek help. Local aquarium societies and online message boards can be your best source of info, especially if you're not fortunate enough to have a good LFS that is current with the latest information.

Now that you know how to spot problems and where to find help, how do you actually translate that into good help? The first step is to provide lots of information to the people you are turning to for help. As problems may occur which can be due to anything from an introduced disease (quarantine tanks are a good preventative for this) to basic husbandry problems, the information that is needed for a good diagnosis is vast. Since the person trying to help you is often not in your house looking at your tank, your challenge becomes verbally painting as complete of a picture as you can of both the problem and your entire tank set up. Simply saying "my prized critter doesn't look quite right, what's wrong with it?" is generally met with a blank stare closely followed by a game of 20 questions that often wastes valuable time. The place to start is with a good description of the critter, along with a description of the problem and all symptoms that you observe. Even more helpful, is a good picture of the subject. Following the description of the problem you will want to provide information on when the critter was obtained, any other recent additions or changes made to the tank, and a complete list of all the other inhabitants. Other necessary information is tank size and set up style, i.e. filtration methods, Fish Only set up, Berlin Reef, lighting, flow rates, etc. Also, anytime you suspect a problem you should automatically do a full battery of water tests and report the values for Ammonia, Nitrites, Nitrates, pH, and Salinity. If there is a problem with your invertebrates, Alkalinity and Calcium tests are useful. Don't just merely say my water is good, you should actually provide the numbers. On many occasions, I have discovered that parameters that were originally believed by the aquarist to be fine were actually out of line. All of that information is invaluable in diagnosing problems ranging from disease, water quality problems, to hostilities between aquarium inhabitants. The more information you can provide, the less time will be spent trading questions back and forth and therefore the quicker you will be able to get to the root of the problem. So don't feel shy about chewing off someone's ear or writing a long book report on a message board, and don't feel the need to apologize for giving too many details either. Those of us listening to or reading your information really would prefer to get the long version instead of playing a game of 20 questions to drag out the needed information.

Now that you are armed with some basic knowledge in spotting problems, and what information is generally needed to provide an accurate diagnosis, you should be able to get help rapidly and effectively. Remember to always watch your inhabitants closely to learn their normal behavior; this will help you recognize when their behavior is abnormal or unhealthy. When you do need help to determine why your charges are not behaving right, be sure and provide as much information as possible. This will go a long way in preventing you, and the people trying to help you, from becoming frustrated. Most importantly, it will help you keep your tank's inhabitants both happy and healthy.