Imported fish “fresh off the wheels”.
The importance of this topic cannot be overstated, as it encompasses the causes of most aquarium fish diseases and, consequently, the lack of development in aquarium hobby keeping in our country in recent years. Therefore, it is so vital for regular aquarists to understand these reasons and for everyone who loves this pursuit to change the situation together.
The geography of suppliers is very broad and diverse. Red neon tetras, rummy-nose tetras, and other characins, as well as angelfish, fly in from Colombia. From Brazil come rare loricariid catfish, wild Symphysodon aequifasciatus, and some characins as well. In addition to the ordered fish, interesting “bycatch” arrives from South America: various characins, Apistogramma, Crenicichla, and other cichlids. Some of them have not yet been scientifically described. Various goldfish and other Cyprinidae, loaches and other Cobitidae, elephantfish, various livebearers, etc., are supplied from Malaysia. Finally, from Africa, from Zambia, come the fishes of Lake Tanganyika.
Where does the aquarium fish trade begin? With catching them in the wild, holding them at suppliers’ facilities, and multi-stage transportation to various countries around the world, reaching quarantine bases, primary wholesalers, and then pet stores and other retailers. Often during this time, the fish are repacked many times, kept for short periods in water with different and frequently changing characteristics, and repeatedly endure air travel and numerous chemical treatments, sometimes unsystematically and haphazardly. Know this, and let there be no illusions: no matter what fish comes to us from abroad, whether caught in the wild in Brazil or bred on farms in Southeast Asia, any of them is always a carrier of various diseases, sometimes in hidden and even difficult-to-determine forms. Why things stand this way, and what it leads to, you will learn and understand by reading this article.
The quality of imported fish on the shelves of domestic pet stores depends mainly on three factors: the level of knowledge, experience, and integrity of exporters; the skill and desire of our domestic importers to adapt and treat this fish; and how they, and all other wholesale traders, maintain it afterwards.
First, let’s look at how things stand at the collection sites.
Ichthyopathological analysis of fish arriving from abroad reveals a whole bouquet of pathogens: bacteria, amoebae, flagellates, fungi, parasitic crustaceans, and flukes of various classes, sometimes difficult to identify. All of this is present in abundance on the gills, skin, circulatory system, and intestines of imported fish, especially those imported from Southeast Asia. Sometimes a single fish species may harbor more than a dozen diverse diseases, as is always the case with goldfish coming from Asian countries. Fish are infected with these infections both in natural biotopes and, especially, on fish farms where they are usually kept in ponds with very high stocking densities, and sometimes in channels or simply dirt pits with dirty water. Water is drawn into such systems from the nearest river without any purification or treatment, and Asian—let alone Latin American and African—fish farmers, with few exceptions, have no concept of modern filtration systems.
Before shipment from supplier countries to recipient countries, fish undergo “preparation.” In most cases, this consists of sorting groups of fish, often very roughly by species and size, and placing them in small containers (sometimes just wooden crates lined with polyethylene on the inside), occasionally even without aeration. In these holding tanks, the fish are not fed for 2-3 days, and sometimes longer, to clear the intestines before packaging. In principle, this is correct, but sometimes shipment is delayed, and then either the fish are fed and fail to clear out by the next shipment, meaning they get poisoned on the way, or they are not fed for several more days and become exhausted, sometimes irreversibly. The stocking density of the fish is usually increased even further, and no additional safety measures are applied. Before shipment, the fish are kept on mild preventive medications that do not cure existing diseases but only hold back their development. And many companies, mostly in Asia, do not treat the fish with anything at all and do not even process them against parasites.
When packaging fish for air shipment, suppliers generally do not add any special and much-needed anti-stress and antiseptic preparations to the water bags. Suppliers from Peru and Thailand suffer particularly from “forgetiveness.” Also, during quarantine, many facilities do not use medications at all. It is easier and cheaper for Asians to throw away even half of the fish and send the rest to customers. Indeed, thanks to cheap labor, free climatic resources, and vast territories, it is economically unprofitable to develop technologies; therefore, when exporting fish, suppliers rely on quantity and remain at the level of the dark Middle Ages.
Things are no better in some Latin American countries. Often, in intermediate facilities at wild fish collection sites, even worse unsanitary conditions and a lack of control over work processes prevail. There are cases when some particularly unscrupulous suppliers from South America pack barely living or even dead fish for shipment, wrong sizes, and completely wrong species than ordered. The trick is that they always take payment in advance and 100%, not only for the fish itself but also for delivery. Therefore, importers have no choice but to adapt to working conditions with foreign suppliers or not work with them at all, as has been the case with the Peruvians for five consecutive years.
After a few days of maintenance without feeding, the fish are packed into bags and sent along a long transport route: from local catchers or pond farms by car to a small aviation airfield, then by a local flight on an old prop plane to the nearest international airport, and from there all over the world. Before arriving at the destination, the fish sometimes go through 4-5 intermediate stops. Naturally, after such trials, the fish arrive completely sick, exhausted, on the verge of life and death. To the horrors of fish farms and quarantine facilities are added stress and severe poisoning in transit, because it has happened that even Germans, having received a cargo for Russia and obligated by mutual agreement to change the water in the bags, did not do so, but simply pumped oxygen into the bags, and even then not always.
Dense stocking in bags to which no necessary preparations have been added leads to the active reproduction of bacteria and parasitic protozoa. By the end of the journey, the oxygen content in transport bags gradually drops to critical levels. The further condition of the fish depends on the oxygen level at which the fish arrived, even if they were still alive, because with a high degree of oxygen starvation or poisoning by metabolic waste products, irreversible processes can begin, and at that point, treating the fish is truly useless. The kidneys suffer first, followed by other organs.
But let’s return to the period preceding shipment. Some will say: “But there are higher-level facilities in Asia, where there are concrete tanks and even aquariums in indoor rooms.” Yes, such facilities exist; these are mainly discus and arowana breeding farms, but even in such facilities, in these zones of apparent cleanliness, fish are not kept at all stages of their development, and part of them, as well as the food base, are placed in the open air. Hygiene rules are observed only in VIP zones and showrooms. Parasites and infections through water and via aquatic animals and birds are freely carried from one body of water to another, from one farm to another, and are always present in them, just in different concentrations. Due to these and other reasons, complete treatment in such farms is excluded, and many types of bacteria, fungi, and protozoa manage to adapt to the applied medications and acquire stable immunity to them. The condition of the fish concerns exporters only until customers receive them. The fish arrived alive, or almost alive – and good, and from then on all problems are exclusively the recipient’s. No suppliers bear responsibility for the fish’s quality or the presence of diseases.
Well, if some of the fish in the bags arrived dead and even decomposed (i.e., died at the very beginning of the journey), rest assured – this is not the whole loss; for most species, this is just the beginning, because the surviving fish are already poisoned, their immunity is weakened to the limit, and diseases are taking over the organism. This applies to most characins, glass catfish, and other fish without the strongest immunity. You might ask, why do Russian firms work with them and constantly receive fish from them? Well, there is simply no choice; they are all almost identical, and one has to choose the best of the worst.
An even scarier picture was described to me by people who visited one of the African countries. For the “holding” of Erpetoichthys calabaricus, locals dig pits, approximately 2 by 3 meters in perimeter and a meter deep. They pour water from a ditch into them and dump several thousand fish into this pit. The fish are kept here for several weeks, and naturally, no one feeds them. In the local forty-degree heat under conditions of enormous overcrowding, dead fish decompose by bacteria and fungi in less than a day, and parasitic microflora develops completely uncontrollably. Ichthyosporidiosis is especially rampant—a terrible fungal disease affecting internal organs and the central nervous system. A mass fish kill occurs, and those individuals that remain alive are shipped to other countries.
Erpetoichthys calabaricus, like all lungfish, is a fish with very strong immunity, but even it cannot withstand a thousandfold excess of ichthyosporidium spore concentrations in the water. Sometimes this fish arrives with already decomposed intestines and other organs, but it is still alive. Treating this disease at this stage is practically impossible, and at best, importers survive a third of the shipment, even if they receive this fish not from Nigeria, but from Germany. But this fish, two days after receipt, is taken to the Moscow Bird Market, where sellers have a chance not to lose 2/3 of their fish, but “in a friendly way” to shift it onto someone else’s shoulders. Forget about the hobbyist Bird Market that once existed. Such a market, unfortunately, no longer exists. Now the main thing is just to sell, and as much as possible.
The overwhelming majority of fish entering our aquariums is imported from Southeast Asia. While a few years ago the palm of victory in these supplies unquestionably belonged to Malaysia, today this country, where most large fish farms are concentrated, is losing its position, and Singapore is now emerging as the leader in supplies. However, from the standpoint of the health and quality of the incoming fish, this changes very little. Not only is fish from Singapore just as heavily infected as Malaysian fish, but suppliers from Singapore also manage to save on fresh water. Often in the bags of fish flying from this island city-state, the mass of water is less than the mass of the “live goods.” Of course, with such “dry” packaging, significant doses of tranquilizers are added to the bags, and the fish arrive heavily poisoned by nitrogen compounds—simply put, they poison themselves in their own excrement.
There are also species, such as Puntius denisonii, which fundamentally do not tolerate tranquilizers well and require 2-3 times more water during transport than many other species. These are highly stress-prone species. The metabolism of such fish slows down only slightly, and as a result of ammonia and nitrite poisoning in transit, every fourth or fifth fish dies. And sometimes the results of poisoning manifest even a month later. Remember, poisoned fish have weakened immunity, so they can die not only from all sorts of diseases whose development accelerates with weakened immunity, but also from metabolic disruptions, which are sometimes irreversible.
Fish sizes in ichthyology and aquarium keeping. 
