This article is from the WeChat public account: ifish ornamental fish
Column | Hans-Georg Evers
Mr.Fish | Hans-Georg Evers
Hans is the editor-in-chief of Amazon Magazine.
A super enthusiast who loves ratfish.
This article is an excerpt from the November-December 2015 issue of Amazon Magazine
Translated / Wang Zhongjing | © edited by ifish
Some people don't think Corydoras are particularly pretty, others think they all look the same, but I think each of them is beautiful. In this article I will talk about several fish species, including common as well as rare rat fish.
Ever since I started raising and studying tropical fish. The ratfish has always been my faithful companion. I have caught countless species of ratfish in the wild and raised them in aquariums, and there are several species that I have successfully bred.
There are at least 500 species under the corydoradinae subfamily of the catfish family, which live in the tropical and subtropical lowland waters of South America. They are systematically divided into the genus Aspidoras, Brochis, Corydoras, and Scleromystax, with many members living in our aquariums. The species-rich genus Corydoras is my favorite. The genus includes more than 170 species, making it the most abundant catfish genus to date, and more will be added in the coming years: several scientists are busy describing new species. Long-awaited and very importantly, this genus is divided into revisions of several subgenera. We aquarium enthusiasts will have to relearn our classification in the future.
Ratfish are ubiquitous in the aquarium pet market. In addition to the basic species, the coffee rat (Corydoras aeneus) and the chipmunk (C. In addition to paleatus, there are several attractive and easily accessible species, including the corydoras panda and the red-winged pearl rat (C. sterbai) and the black and gold red-headed rat (C. sterbai) duplicareus）。
Is the beautiful red-winged pearl rat (Corydoras sterbai) the prettiest ratfish? Many aquarists do think so.
These species are rarely available to wild-collected individuals; they are often artificially bred. This is a good thing, especially for novices, because captive breeding fish simulations are stronger and more tolerant of aquarium enthusiasts' mistakes. Most common breeds are fairly easy to keep and deserve to be labeled "strong and strong", but I can't help but get angry when people call them "vacuum cleaners" and "scavengers". Even hard-working animals should be well fed and should not be reduced to leftovers.
Do your homework!
In recent years, the care and rearing of ratfish has been given a lot of space in the aquarium literature, and we hear about many successes than failures. However, some rat species are considered almost impossible to reproduce. Frankly. I find it surprising that even some of the so-called "experts" have little idea of their natural habitat. Several times, I was asked how some particularly difficult species lay eggs. My answer is always the same: "Friend, do your homework first!"
We usually know which country, which state and which river basin a species comes from. There are climate tables and other data for these habitats on the web, from which a lot of information and clues can be obtained about how to raise a species in aquariums. For example, when of the year is the area low or high? Does the species live in large rivers, streams or lakes? If you can find this information, you should make good use of it. I know that many aquarists start by simply setting up a fish tank based on what the book says and want the best results. For these people, whether the species can reproduce depends on luck. This is not enough for some species, as constant environmental conditions do not provide them with a reason to reproduce. This is true for some snout-type species, such as the Corydoras haraldschultzi and other species. If their keepers had not replicated the same natural conditions in the aquarium, nothing would have happened.
The Crown Black Pearl Rat inhabits local waters alongside the Red-winged Pearl Rat, but when the Crown Black Pearl Rat is about to breed, the requirements become higher.
However, the focus of this article is not to talk about their care and reproduction, but I would like to draw your attention to the provision of several kinds of information about the habitat of the ratfish that I like very much and that the average person may not know.
Corydoras noelkempffi in the Rio ltenez basin of the Ittnes River in Bolivia. This breed is found in a very small area and can only occasionally be found in captured red-winged pearl rats or crown black pearl rats, so keep your eyes open.
Due to its size and interesting patterns, the Panda Mouse (Corydoras panda) became one of the hottest mouse fish
Gorgeous ratfish
Among German aquarium players, the name Pracht-Pan-zerwelse refers to a special group of ratfish with dotted markings on a light or dark base, and some species have orange pectoral and ventral fins. In particular, I think of the populations of the crown black pearl rat and the red-winged pearl rat in the Guapo River basin of Brazil (believed to be in the Itenez River in Bolivia). A second group of Corydoras araguaiaensis from the middle reaches of the Aragua River in Brazil and similar species are also included. There are also two beautiful species in the Rio Mamore basin from the Guajara-Mirim region. Gorgeous ratfish are a popular ornamental fish that is regularly offered in Fish Shops in Germany, and may be less common elsewhere.
The municipality of Pontes e Lacerda, in the southern part of Brazil's Mato Grosso state, southeast of the Pantanal Wetlands, flows into the Rio Cuiaba and further into the Rio Parana, as well as the upper valleys of the Rio Guapore River bordering Bolivia. If it were not for the red-winged pearl rat, the guabo rat (C. Guambo rat). guapore) and other fish species are already deeply rooted in the hearts of aquarists, and no one will know about this area. The vast Guabo River is home to a herd of ratfish. In western Brazil, the states of Yaqui, Rondônia and Mato Grosso (southwest of Pantanal), all of which flow into the Rio Madeira, are hotspots for this group of fish. On this 12-day trip up the Madira River, I caught 19 different species of ratfish. In some places, as many as five different species of ratfish have been found in a single small river.
Even the vast Guabo River itself has many ratfish. The main river water is transparent and slightly acidic, and always maintains a warm water temperature of 28-30 ° C. Smaller rainforest streams (igarapes) and rivers shaded by rainforest can sometimes cooler by a few degrees. There are many varieties in the numerous tributaries on the Brazilian and Bolivian sides, but we know very little about the varieties that live in Bolivia. The red-winged pearl rat inhabits both the main stream and some of the larger tributaries.
In this waterway, we found hundreds of gold-winged monarch rats Corydoras gossei adults and its barramundi species, the long-snouted gold-winged monarch mouse C. seussi
At the end of the rainy season and the onset of the dry season, juveniles swim in whole groups into shallow waters, sometimes in large numbers, and they will find something to eat on the bottom of the sand. When they mature and heavy rainfall begins at the end of September, these large groups are divided into smaller breeding colonies. It starts during the early winter spawning season and continues until February or March. Since then, fishermen have caught these juveniles in large numbers. Among the many red-winged pearl rats they often find a few crown black pearl rats, or occasionally C. Eyschs., isbrueckeri), C. Noe noelkempffi) and the black-waisted leopard rat (C. spectabilis）。
It should be noted that the red-winged pearl rat is a "super species". Individuals from the lower to middle reaches of the Guabo River look very similar, although there are different endemic types ("Black Black" and "Bolivian"). In contrast, the species of the barramundiform type are diverse and belong to the highly differentiated and distributed species. We know that the Crown Black Pearl Rat comes from the Pontis and LaSeda regions on the Brazilian side, while the Noe catfish live further upstream, on the Bolivian side of the Rio San Martin, a tributary of the Itenes River. The red-winged pearl rat is always found with these species, and despite their diversity of individual manifestations, they all belong to the same individual variant.
A widely distributed species such as the red-winged pearl rat can adapt to many different habitats. These species are usually easier to raise and easier to spawn. However, when an aquarium player wants to spawn an endemic species that has adapted to specific habitat conditions, it sometimes requires more attention and effort. The barramundi species also seem to expand into other different areas over their life course. It's hard to prove, but I and J. Knaack (pers.comm) has observed that these ratfish migrate widely throughout the Amazon, while the snout species are only distributed at the headwaters of the rivers where they are born and in smaller tributaries. In the process of development, they migrate to the mainstream and downstream to obtain a richer food source, especially in flood areas. After the flood waters recede, the fish will only swim back to their original habitat in their entirety. Taking advantage of this advantage, fishermen will collect a large number of barramunks as an export at this time. The best example is the thousands of wild Batman rats (C. Batman rats) caught each year in the lower reaches of the Rio Purus and appearing in the global aquarium trade. schwartzi) and the white-winged leopard rat (C. schwartzi) sp. C141）。
The golden-winged monarch mouse
Do you know the gold-winged monarch mouse? If you know, you may agree with this ratfish and its parody of the barramundi - the long-nosed gold-winged monarch rat (C. long-nosed gold-winged monarch rat). seussi), both have very different body colors from other ratfish. Healthy, stable individuals have a dark blue back and bright orange dorsal, ventral and pectoral fins. When I visited the natural habitat of the Guayarami forest area near the Mamo River (Rodunia) in October 2000 to observe them, I was well aware of both species. However, I was amazed at the beauty of the individual I had just captured.
A narrow deep stream flows from the remnants of the rainforest that spans the pasture towards the Mamo River. We quickly climbed over the fence and sat down at the water's edge. The clear, slow-flowing river water (11 μS/cm, 29.5°C before the end of the dry season) is brown in tan, and we can't see the bottom. Soon, rising bubbles indicate that there may be a swarm of ratfish searching at the bottom. After we used the large fishing net to cast the net in the direction of the bubbles, several gold-winged monarch rats and long-snouted gold-winged imperial rats twisted in the nets. I'll never forget the bright colors of these ratfish when they were first caught.
The wild gold-winged monarch rat (Corydoras gossei) is photographed after being captured
Gold-winged monarch rats are not very shy in aquariums, and when they are fully adapted to the environment, they will show attractive colors
The spawning season for both species is from December to January. In February, juveniles of both species can be easily collected in large quantities. Another very rare ornate ratfish habitat is only a few hours' drive away. The long-snouted grey pearl rat (Corydoras pinheiroi) inhabits the Agua Azul Creek in the village of Villa Nova. We caught this harp fish in this clear sandbar shoal at night (pH 6.7, 24 μS/cm, 26.5 °C) along with the C040 rat (Corydoras sp. C40), C. C. (C. trilineatus), caffeine similar species (C. cf. Aeneus) and Christina Rat (C42).
Unfortunately, the beautiful and classic long-snouted grey pearl rat (Corydoras pinheiroi) is rarely imported
Author's favorite rat fish: Corydoras sp. C65
We caught several C65 rats under the embankment of this creek
A spectacular sight: a bag of freshly caught C65 rats.
Brazilians call it Corydoras sp." Guarana"，
"Guarana" is a local lemonade drink.
【Next Issue Preview】
Due to the length of the article, we will present it in two parts.
In the next issue, we will take a closer look at the natural habitat of the Rio Araguaia River and Rio de Janeiro to interpret the ratfish, so stay tuned.
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