Author Archives: Frank Schäfer

So-called gold tetras are found in many species of characins in South America. Usually, only a few fish in a school are affected by the phenomenon in which guanine, the substance responsible for the shiny silver or gold glitter effect of the fish scales, is secreted at a much higher rate than usual. We explain this in detail here: https://www.aquariumglaser.de/en/fisharchive/hyphessobrycon-saizi-hyphessobrycon-eos-colombian-gold-tetra/) For the reasons described, the golden sheen cannot be fixed in breeding strains. The offspring of all gold tetras look like the regular form.

However, it is precisely in a tetra, in which wild-caught gold tetras are almost never found, that the genetic fixation of the golden sheen has been achieved. Breeders call this attractive silver-shining fish “diamond,” but it is usually referred to as “platinum” in the trade. The precious metal sheen of this rummynose tetra – technically speaking, Petitella bleheri – is due to a random genetic mutation, not parasite infestation. For information on distinguishing between the three rummynose tetras and general care instructions, see https://www.aquariumglaser.de/en/fisharchive/petitella-rummynose-tetras/

For our customers: you can find the animals on our stock list as “Hemigrammus rhodostomus Platinum” with the code numbers 257362 (md) and 257363 (md-lg). Please note that we only supply wholesale customers.

Text & photos: Frank Schäfer

Nannostomus mortenthaleri from Peru (Rio Nany tributary in the province of Loreto) was the most beautiful new discovery in aquatics in 2000. The close relative of the dwarf pencil, N. marginatus, remains small – approx. 4 cm – and is breathtakingly beautiful in color in the male sex. At least sometimes. Because apart from anatomical details, N. mortenthaleri exhibits behavior that clearly differs from most Nannostomus species. Among conspecifics, N. mortenthaleri forms a distinct hierarchy or pecking order.

Dominant males display an intense red color between the dark longitudinal bands. Lower-ranking males fade and take on the coloration of females. Conversely, dominant females can develop a significant amount of red. N. mortenthaleri‘s behavior is therefore more similar to that of a small Malawi cichlid (Mbuna) than to that of an pencil fish. It is therefore essential to keep this species in a larger group, as otherwise, just like with Mbunas, a tyrant may develop that oppresses all conspecifics so severely that it can even lead to deaths. The gender composition is irrelevant for keeping them in a community aquarium.

In all pencil fish, the shape of the anal fin has proven to be the most reliable sexual characteristic. Unfortunately, the differences are very slight in N. mortenthaleri. The anal fin of adult males is always slightly convex at the front edge, whereas in females it is straight. In addition, females lack the light stripe at the base of the dorsal fin. However, the most reliable way to distinguish between the sexes is by their behavior. We recommend purchasing a group of 10-20 specimens, which should be kept in a larger, heavily structured aquarium (with lots of roots and dense planting). The fish will certainly spawn here (they are open spawners over fine-leaved plants). Although there is hardly any offspring in community tanks, as the adult fish are very cannibalistic, at least you know whether there are really females in the group and can catch them specifically for breeding.

N. mortenthaleri are relatively easy to care for. They adapt well to different water parameters, although soft and slightly acidic water best corresponds to their natural conditions. The water temperature can be between 22 and 28°C. They will eat any standard ornamental fish food of a suitable size. N. mortenthaleri are usually peaceful towards other fish species, but caution should be exercised with closely related Nannostomus species with a similar body shape and coloration.

For our customers: N. mortenthaleri has code 272253 (md) – 272257 (xlg), depending on size. Offspring have code 272259 on our stock list.

Text & photos: Frank Schäfer

One of the first tetras ever imported for aquariums is Hyphessobrycon flammeus. Since its first import in 1924, the species has never disappeared from aquariums, as it is easy to breed and the fish are very productive. Due to its origin (the area around Rio de Janeiro in Brazil) and its pretty red color, the species quickly gained a popular name, namely “Flame Tetra,” especially since the species was still unknown to science at the time of its first import.

Unfortunately, the Flame Tetra is threatened with extinction in the wild, as its natural habitat (coastal forests) is disappearing more and more. There have been no imports for many decades, but by purchasing Flame Tetras, you can actively participate in species conservation, because as long as aquarists demand Flame Tetras, they will continue to be bred and can at least survive in aquariums.

The fish display their optimal coloration in natural conditions: brownish, relatively cool (16-22°C) water colored by humic substances. However, the fact that this species has existed for 100 years without any “blood renewal” in the hobby clearly shows that the Flame Tetra is an adaptable animal that can thrive under a wide variety of conditions. Any commercially available ornamental fish food of a suitable size is accepted. An important note: Hyphessobrycon flammeus kept individually or in pairs can become very aggressive towards tank mates, so please keep at least 10 specimens together, regardless of gender. Males differ from females in that they have a stronger black border on their anal fin and black ventral fin tips.

For our customers: depending on their size, the animals have codes 260300 to 269304 on our stock list. Please note that we only supply wholesale customers.

Text & photos: Frank Schäfer

The rummynose tetras are a beautiful eye-catcher for any aquarium with peaceful fish. A shoal of these animals, and there should always be 15 – 20 specimens if possible, delights every observer because these animals really do swim permanently in a shoal; the vast majority of so-called shoal fish among aquarium fish do not do this. They tend to swim around the aquarium in scattered pools and only swim close together when danger threatens. Rummynose tetras are not difficult to care for and so they swim in many aquaria. Only the correct naming of the species is not easy. We know of three species that have been confused again and again. They used to be divided into two genera (Hemigrammus and Petitella), but nowadays all three are classified as Petitella: P. rhodostoma (formerly: Hemigrammus rhodostomus), P. bleheri (formerly: Hemigrammus b.) and Petitella georgiae.

These three species have been and are so often confused that you can get really confused. In fact, it’s relatively simple: the fish on the market are almost always Petitella bleheri, but they are almost always referred to as Petitella georgiae. Basically, it doesn’t matter which of the three species you buy, as they don’t differ in their requirements. Nevertheless, we will list the differences here for those who want to know exactly.

E. Ahl described a rummynose tetra as Hemigrammus rhodostomus a long time ago, in 1924. It was found near Belem in Brazil. And so, namely as Hemigrammus rhodostomus, every rummynose tetra in the aquarium hobby was subsequently named. It was certainly noticed that the fish looked slightly different depending on where they were found, but this was thought to be an intraspecific variation.

In 1964, the tetra specialist J. Gery and H. Boutiere described a species very similar to the already known rummynose tetra as Petitella georgiae. The differences in the coloration of the two species are insignificant, the reason for the species separation was due to differences in the dentition. This new species originates mainly from the upper reaches of the Amazon in Peru. It was not particularly widespread in the hobby because it is somewhat less colorful than the rummynose tetra, which was already known.

However, the most beautiful rummynose tetras came and still come from the Rio Negro. They have a magnificent red head coloration that extends far beyond the gill covers. Coveted fish need their own trade name and so the new name Petitella georgiae was used for this tetra without checking the accuracy of this undertaking.

In 1986, J. Gery together with V. Mahnert described this reddest of all rummynose tetras as a new species, Hemigrammus bleheri, and the chaos was perfect because each of the three species had already been illustrated in the literature under an incorrect name.

P. bleheri can always be easily recognized by the fact that, unlike the other two species, it does not have a black longitudinal band on the caudal peduncle, but only a pale grey line. Petitella georgiae and P. rhodostoma have a distinct, clearly visible dark longitudinal band and can hardly be distinguished visually. In acclimatized animals it is best to look at the end of the caudal peduncle. Petitella has only one spot at the top in front of the caudal fin, P. rhodostoma has a spot at the top and bottom.

We mostly import P. bleheri from Brazil, but for reasons of our in-house merchandise management analysis it sails under the name “Petitella georgiae”, but from time to time we also have wild-caught “real” P. georgiae from Peru in stock. P. rhodostoma is hardly ever sold under its real name. The pictures we show here are of so-called by-catches, which we sorted out from imports of other fish species. P. bleheri is not only offered as a wild catch, but also as offspring. There are also cultivated forms of P. bleheri: Gold, albino and platinum forms show the large scale on which this species is bred.

In terms of care, it can be said that the adaptability to different water conditions is so good that it can be said that rummynose tetras of all kinds can be kept well for years in any tap water suitable for drinking. Their coloration is optimal in water to which humic substances have been added. Soft and acidic water is required for breeding. The sexes differ in shape (females are larger and rounder in the belly area) and the males have small hooks on the anal fin with which they get entangled in the net. The water temperature should be between 24 and 28°C, a little higher for breeding, sometimes a little lower won’t do any harm either. They will eat any common ornamental fish food of a suitable size, plants remain undisturbed. Petitella are very peaceful towards all fish species.

For our customers: unfortunately, for accounting reasons, it is very difficult to change the names in our stock list. For this reason, P. bleheri cultivated forms (Gold 257301-257303, Albino 257352 and Platinum 257362-257363) and captive-bred specimens (code 257201-257205) can be found under Hemigrammus rhodostomus, wild-caught P. bleheri from the Rio Negro under Petitella georgiae (code 278001-278005) and the “real” P. georgiae from the upper Amazon (Peru) under P. georgiae/real wild PERU (code 278014). Please note that we only supply the wholesale trade.

Text & photos. Frank Schäfer

At present the small tetras of South America experience a new boom. Numerous species have been and are being described scientifically. Thus also the ornamental fish collectors leave their beaten tracks and look for these animals, particularly since initially peppered prices are paid for the novelties. Naturally, such a thing only works for a short time, then offspring of the particularly attractive species come onto the market, the less attractive ones disappear again and wild catches only come to us once in a blue moon as rarities for a few specialists. 

One of these new species is Hyphessobrycon negodagua, which was scientifically described in 2001. Its area of origin is in the northeast of Brazil, in the state of Bahia. There, this tetra with a maximum length of 3 – 3.5 cm inhabits the Rio Pratinah, a tributary of the Rio Santo Antonio, which in turn drains into the Rio Paraguaçú, which is one of the important coastal rivers of Brazil without connection to other river systems. H. negodagua differs from almost all other Hyphessobrycon species by the absence of the typical tetra adipose fin in most specimens, the unique coloration of the males in courtship display also makes them distinctive. Freshly imported and not yet acclimated animals are silvery, but acclimated males show already after a few days their fiery courtship dances, during which they turn black, which contrasts very effectively with the white fin seams. The fluttering courtship swim of this pretty species prompted Hans-Georg Evers to call it the “Butterfly Dwarf Tetra”.

The care of the animals is simple and corresponds to that of other small tetras. Incidentally, the species name “negodagua” refers to a mythical man-like monster (Nego d’agua) that lurks at the bottom of rivers and attacks inattentive fishermen at night. Why scientists associated the small, peaceful tetra with this monster, they do not reveal….

For our customers: the animals have code 261232 on our stock list. Please note that we only supply wholesale. 

Text & photos: Frank Schäfer

The genus Curimata currently comprises 13 species; only one of these occasionally finds its way into our aquariums, namely Curimata vittata. The other species simply offer no incentive to keep them. They are shiny silver-colored animals that can reach a length of 15-20 cm and feed mainly on plant material.

Curimata vittata also reaches this length, but unlike its genus counterparts, it is quite attractively colored. An irregular tiger pattern runs across its back, its generally silver-colored flanks shine greenish or golden depending on the incidence of light, and a golden-yellow band runs along the middle of its body.

The strange mouth structure shows that they are Aufwuchs feeders. From our hobby, we are familiar with kissing gouramis (Helostoma) and flagtail tetras (Semaprochilodus), which also feed in this way. Only fine particles should be fed to these fish, as they have a narrow throat. Suitable foods include plant-based flake food finely rubbed between the fingers, frozen cyclops, Artemia nauplii, or finely ground oatmeal (caution: this pollutes the water heavily). C. vittata is widespread in the Amazon, upper Orinoco, and Essequibo River; our specimens come from Colombia. They are peaceful, somewhat shy fish that should definitely be kept in groups. Single fish are extremely shy.

For our customers: the animals have code 251203 on our stock list. Please note that we only supply wholesale customers.

Text & Photos: Frank Schäfer

Currently (September 2025), 28 species are assigned to this genus. The genus was established in 1907 by Eigenmann for the species Tetragonopterus pectinatus, described in 1870 by Cope from Peru (Pebas). Cope’s description was not accompanied by any illustration, so Fowler drew the holotype in 1907, which he classified in the genus Astyanax. Based on this drawing, it would be difficult to recognize a Phenacogaster; no wonder, then, that Steindachner fabricated two synonyms for P. pectinata in 1876 and 1882: Tetragonopterus tabatingae and T. bairdii. That was it for the 19th century.

The characin specialist Eigenmann described two species in 1909 and three more in 1911, while Norman (1934), Ahl (1936), and Fowler (1941) each described one species. Thus, by the middle of the 20th century, nine species were known, although this is a simplified representation, as not all of them were classified under Phenacogaster. Conversely, the fish described by Fowler in 1911 as Phenacogaster bondi is now classified as Gymnocorymbus, which is undoubtedly correct.

Then there was a long period of silence surrounding this group of tetras. It was not until 1995 that another species description followed, together with a new diagnosis of the genus. Brazilian ichthyologist Zilda Margarete Seixas de Lucena, already senior author of the 1995 paper, discovered these small tetras for herself and began researching them. The result is impressive. One of the species described in 2023, P. lucenae, was named in honor of Lucena and is the 15th new species since 1995! In terms of color, Phenacogaster are certainly no revelation. Most are small, transparent fish, usually with a shoulder spot, often with a tail root spot. They look very, very similar. Anyone who wants to delve into the finer points of species differentiation should start with the 2010 work “Descrição de nove espécies novas de Phenacogaster (Ostariophysi: Characiformes: Characidae) e comentários sobre as demais espécies do gênero” by Lucena & Malabarba (free download here: https://www.scielo.br/j/zool/a/47FyqVP45DrQ3wNV9Jwqt3k/?lang=pt), which discusses all species recorded to date and provides an identification key.

We have now been able to import a previously unknown Phenacogaster species from Peru for the first time. It should be clear that, based on the above list, an exact identification is complicated, as most newly described species are only known from preserved material. But our little newcomer—the animals are about 3 cm long (including the tail fin)—has no shoulder spot, no tail root spot, and comes from Peru. That narrows down the selection. We are probably looking at Phenacogaster capitulata, which was described in 2010 from the Neshuya River basin (part of the Rio Ucayali basin).

When in mating mood, the presumed males develop pretty orange fins with a white tip on the dorsal fin. This makes them vaguely reminiscent of the hummingbird tetra (Trochilocharax ornatus) in color, but they are considerably paler. The neon colors in some pictures are a result of the flash; to the naked eye, the fish are mainly transparent. They are peaceful animals that are best kept in a dimly lit aquarium with dark substrate. Their large eyes indicate that these fish do not like bright light. In terms of care and food, the animals have proven to be completely undemanding in our experience.

For our customers: the animals have code 278312 on our stock list. Please note that we only supply wholesale.

Text & photos: Frank Schäfer

Imagine you have a first import and don’t even realize it! That’s what’s happening to us right now with a tetra. We received some very beautiful, large Hemigrammus coeruleus from Colombia. At least, that’s what we thought. By chance, Peter and Martin Hoffmann, from whom we often and gladly receive rare tetra offspring, needed a few H. coeruleus. Some time later, they asked where they came from. When we answered (Colombia), they said: Flavio is right again: they are Hyphessobrycon acaciae. Flavio refers to Flavio Lima, the tetra specialist from Brazil (Universidade Estadual de Campinas). The two had asked him about the identification of the fish, as they had noticed some differences from the usual coeruleus. 

With the naked eye, it is almost impossible to tell the difference between freshly imported Hemigrammus coeruleus and Hyphessobrycon acaciae, even though they are classified in two different genera. Technically speaking, the only difference between the genera Hemigrammus and Hyphessobrycon is that the base of the tail fin is unscaled in Hyphessobrycon, but scaled in Hemigrammus. This is not noticeable in living fish underwater. It has been known for decades that four of the main groups of South American small characins (the genus pairs Hemigrammus/Hyphessobrycon and Moenkhausia/Astyanax) are artificially classified and do not represent a natural relationship. But the work involved is very lengthy and complex, and it will certainly take quite some time before we really understand it.

For us, this means that we will now always have to carry out a special examination when Hemigrammus coeruleus from Colombia arrive. Using a powerful magnifying glass, we have to check the tail fin for the characteristic scaling, as the subtle differences in coloration are not visible in freshly imported animals that have not yet acclimatized. In terms of general care requirements, the two species do not differ. Both species are peaceful schooling fish that can reach a total length of 5-6 cm (including the tail fin). For H. coeruleus, see here: https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/hemigrammus-coeruleus-4/

Text & photos: Frank Schäfer

The three-banded pencilfish, Nannostomus trifasciatus, is one of the most popular ornamental fish. It combines numerous characteristics that make it desirable: beautiful coloration, peaceful nature, small size, and easy feeding. However, few people know that the name “Nannostomus trifasciatus” actually refers to several species. The “real” N. trifasciatus is relatively rare in stores. It comes from the area around Manaus in Brazil and Tabatinga/Leticia in the border triangle of Peru, Colombia, and Brazil. Its distinguishing feature: above the broad, dark longitudinal band, there is an additional narrow red stripe. Unfortunately, this stripe is easily overexposed and is therefore often difficult to see in photographs.

The twin species, N. erythrurus, is very widespread. It was first described from Guyana, but is also found in Peru and in the lower reaches of the Amazon in Brazil. The red stripe mentioned above is always absent here; only a red shoulder spot is often found. The similarity between N. erythrurus and N. trifasciatus is so great that until 2013, N. erythrurus was usually considered a synonym of N. trifasciatus; N. erythrurus was described as early as 1909.

From time to time, we receive such beautiful N. erythrurus from Peru and Brazil that we also distinguish them as a special species. Otherwise, no distinction is usually made between the two species in the trade.

N. erythrurus and N. trifasciatus do not differ in terms of the positive characteristics listed above. Both are ideal aquarium fish.

For our customers: N. erythrurus has code 272013, N. trifasciatus code 272301-272306 (depending on size). Please note that we only supply wholesale customers.

Text & photos: Frank Schäfer

With 23 species, the genus Hemiodus is quite species-rich. The majority of species grow to a length of 15-20 cm, with the largest reaching around 30 cm. Previously, three genera were distinguished (Hemiodus, Hemiodopsis, and Pterohemiodus). However, the characteristics considered to be differences between the genera proved to be insufficiently relevant. Therefore, all three were merged back into one genus – Hemiodus. 

Hemiodus are sensitive to stress. Their capture, acclimatization, and transport can therefore only be successful with the utmost care. This is the reason why these fish are relatively rare in the trade. All species observed in aquariums to date exhibit a slanted swimming behavior. These elegant animals should always be kept in schools of at least eight, as individual fish can be very nervous. Another basic requirement is a large aquarium with plenty of free swimming space. Hemiodus are peaceful towards each other and towards fish of other species. There have been no reports of breeding in aquariums. Hemiodus can be described as undemanding in terms of water values (pH and hardness) and food (any standard ornamental fish food of a suitable size is readily accepted), but the water should be clear and rich in oxygen. A temperature between 24 and 28°C is probably optimal for all species.

The only species of the genus that is offered relatively regularly is Hemiodus gracilis. It has a characteristic pattern. A strong black longitudinal band begins approximately in the middle of the body and continues into the lower half of the caudal fin. Below this black band, the edge of the tail fin of H. gracilis is deep red – very attractive! H. semitaeniatus and H. goeldii are almost identical in color, but in both species the lower edge of the tail fin is white rather than red. H. semitaeniatus has significantly more scales in the longitudinal row than H. gracilis and H. goeldii (these have only about 50 fairly large scales in the longitudinal row, H. semitaeniatus has over 50, making the scales significantly smaller in relation to the body). You can easily shorten the scale counting by only counting the scales along the edge of the back before the base of the dorsal fin. Here, H. semitaeniatus has well over 20 scales, while H. goeldii has only 12.

We recently received „H. gracilis“ from Colombia, which unfortunately show no red in their tail fins. Closer investigation revealed that they are actually H. semitaeniatus. This species is widespread in South America: it has been reported in Brazil, Bolivia, Guyana, Colombia, Paraguay, Peru, and Venezuela. However, recent genetic studies on Hemiodus (Nogueira et al., 2020) suggest that this is more likely to be a species complex than a single species. The largest specimen of H. semitaeniatus measured to date was 20 cm long.

For our customers: the animals have code 258282 (4-6 cm) on our stock list. Please note that we only supply wholesale customers.

Literature:

Nogueira, A. F., C. Oliveira, F. Langeani & A. L. Netto-Ferreira (2020): Overlooked biodiversity of mitochondrial lineages in Hemiodus (Ostariophysi, Characiformes). Zoologica Scripta v. 50 (no. 3): 337-351.

Text & photos: Frank Schäfer

In 1977 the „bible for all characin friends“ was punblished: Jaques Géry´s „Characoids of the world“. Almost at the end of this book a picture of a so far undescribed glass tetra was published that had an extremely unusual air bladder. This animal was described only one year later – in 1979 – by Richard P. Vari  as a new species, Leptagoiniates pi. The specific name refers to the shape of the air bladder that reminds one in the ancient Greek letter pi (π). Due to the transpareny of the animals the air baldder can be seen very good in live specimens. It was not easy for Vari to place the new species in a already described genus, but finally he decided to place it in Leptagoniates due to anatomical reasons.

New techniques bring new ideas. Two independent molecular analysis showed that the two species placed so far in Leptagoniates (namely L. steindachneri and L. pi) are not closely related at all, but have to be placed even in different subfamilies: L. steindachneri in the Aphyocharacinae, L. pi in the Cheirodontinae. L. pi is a species that is very close to the basal evolutionary branch of the Cheirodontinae. So recently Vari, Bruno F. Melo, and Claudio Oliviera erected a new genus for L. pi, Protocheirodon. This genus is so far monotypical; this means it contains only one known species, Protocheirodon pi. The description of Leptagoniates pi was one of the very first publications of R. Vari. Sadly this publication was one of the last of Richard P. Vari and published posthumous. He died, aged 66, on January 15th, 2016 from cancer.

To the best of our knowledge Lepatagoniates steindachneri has not been imported yet as an ornamental fish. Protocheirodon pi, on the other hand, is available from time to time from Peru. The species has a very wide distribution in South America and can be found in almost all major river systems in the central and western part of Amazonia, including the Solimoes, the Purus, Madeira, and Ucayali. The fish is found unsually over sandy bottoms in quiet waters along the banks of the rivers and in backwaters. There is no sexual dimorphism described, but we feel that the females become bigger than the males. However, this is not proofed by anatomical examination.

Keeping Protocheirodon pi is not complicated at all. We suggest the common name „Crystal Tetra“ for the species. The company of other fish makes P. pi feel safe. This must not necessarily be conspecifics, other peaceful fish can also do that job. P. pi is not a schooling fish in the strict sense of the term. Once the fish have settled in a tank they will inhabit very small territories that will be defended in a harmless way against other Crystal Tetras. One can term P. pi as an absolutely peaceful species. The fish will readily take any usual fishfood that fits in size. Plants are ignored. P. pi attains a maximum lengst of about 5 cm.

For our customers: the fish have code 266003 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & Photos: Frank Schäfer

We were able to import this cute dwarf tetra from Peru for the first time in April 2003. Since then, we have succeeded in importing it from time to time. The fish was initially provisionally called “Heterocharax sp. – Orangefin Tetra” or “Hummingbird Tetra”, sometimes also referred to as “Tyttocharax sp.”. A. Zarske scientifically described the species in 2010 as Trochilocharax ornatus and also created a new genus for it. Depending on the lighting, the barely 2 cm long jewels shimmer blue or are transparent. This dwarf tetra is extremely lively and has so far proved to be easy to keep.

Males and females are very easy to distinguish, as the males have an elongated dorsal fin and colored ventral fins. The maximum length of these animals is less than 2 cm (excluding the caudal fin), males are significantly larger than females. The hummingbird tetras are adaptable with regard to close-up feeding and chemical water conditions. Any common ornamental fish food of a suitable size is readily accepted. They ignore other fish and plants.

Interestingly, these tetras have internal fertilization. It is not yet clear how they do it, but the females lay fertilized eggs on plant leaves and roots without the presence of males; of course, they must first be kept together with males. Apart from the tiny size of the young, breeding does not present any particular difficulties. You can find a free breeding report online (in German only) here: https://www.datz.de/suesswasser/243-der-kolibrisalmler-ein-zwerg-mit-innerer-befruchtung

For our customers: The fish have code 258332 on our stocklist. Please note that we only supply the wholesale trade.

Lexicon: Heterocharax: means “deviant Charax”. Charax is a different genus of characin. Trochilocharax: after the scientific word for “hummingbirds”, Trochilidae, which in turn is derived from the ancient Greek word “trochilos”, which was used by Aristotle for a small bird. Charax is another tetra genus. ornatus: Latin, means “adorned”. Tyttocharax: ancient Greek, means “tiny charax”. Charax is another genus of characin.

Text & photos: Frank Schäfer

The genus Brycon comprises around 45 species, which are distributed across large parts of South and Central America. They hardly play a role in aquaristics, but are very important as food fish. They are medium-sized to large fish. The smallest species belong to the B. pesu complex (approx. 16 cm standard length, i.e. without caudal fin), while the largest – whose impressive appearance captivates the eye in underwater photographs and shapes our perception of Brycon species in general – can reach a standard length of over 70 cm.

The species Brycon pesu was scientifically described as early as 1845. Since then, all smaller Brycon species with a black caudal fin band and/or black adipose fin from Brazil, Bolivia, Ecuador, French Guiana, Guyana, Colombia, Peru, Suriname and Venezuela have been called “Brycon pesu”. It has been firmly assumed for decades that this is not a single species, but a species complex. The actual Brycon pesu would then probably only occur in the Guyana Shield. We have now received Brycon from the complex around B. pesu from the Araguaia/Tocantins basin in Brazil for the first time. The B. cf. pesu occurring there were only recently examined in a scientific paper (Panarari-Antunes et al, 2008). It was found that the two different color types of “Brycon pesu” from this water system are actually two different, genetically clearly representable species. One species has a red stripe in the anal fin as a clear external distinguishing mark, the other does not.

Unfortunately, we received the species without red stripes (the other one would certainly be even more attractive). We named it Brycon cf. pesu1 according to the suggestion in Panarari-Antunes et al. This Brycon may not have particularly striking colors, but in our opinion it is still an enrichment for the hobby. Tetras of this medium size class, which enliven an aquarium with medium-sized cichlids and catfish, are rather rare. There is not too much to say about the care requirements of Brycon cf. pesu1. They are lively schooling fish, playful and peaceful. As this is a first import, we are not yet able to provide any long-term experience. Our animals willingly accept any common ornamental fish food, the water temperature can be between 22 and 25°C, probably a little higher is also possible. Other fish species from the Araguaia/Tocantins have shown good adaptability to different water parameters (pH and hardness). In nature, the water there is soft and slightly acidic. The aquarium for Brycon species must be well covered, as they are excellent jumpers.

For our customers: the animals have code 212713 on our stock list. Please note that we only supply the wholesale trade.

Literature:

Panarari-Antunes, R. S., Prioli, A. J., Prioli, S. M. A. P., Júlio Jr, H. F., Agostinho, C. S., & L. M. Prioli (2008): Molecular variability in Brycon cf. pesu Müller and Troschel, 1845 (Characiformes: Characidae) from the Araguaia-Tocantins basin. Genetics and Molecular Research, 7(1), 95-106.

Text & photos: Frank Schäfer

Internationally, the largest serrasalmid species are called “pacu”: the red bellied pacu (Piaractus brachypomus, formerly Colossoma brachypomus or C. bidens) from the Amazon system, its twin species P. orinoquensis, which has only been differentiated from it since 2019, the yellow pacu (P. mesopotamicus) from the Parana-Paraguay system and the black pacu or cachama (Colossoma macropomum) from the Amazon. They all grow to around 80 cm in length and weigh over 20 kg. They are kept in aquaculture as excellent food fish and one species – the red bellied pacu – is probably now widespread in the tropics worldwide. In their native countries, however, these pacus are called Pirapitinga and the silver dollars of the genus Myletes & Co are referred to as pacus.

Anyway, red pacus are a must in any display aquarium as they are impressive creatures. However, we do not import them as large fish, but as small fish just a few centimetres long. They are usually bred ones from South-East Asia. As juveniles, red bellied pacus imitate a notorious cousin, the Red Piranha (Pygocentrus nattereri). In fact, they are almost indistinguishable from each other in terms of color. It is called Batesian mimicry when a harmless species imitates a defensive species and thus benefits from the fact that potential predators tend to be cautious.

Aquaristically, of course, it is known that piranhas represent the carnivorous branch of serrasalmids, while pacus are mainly vegetarians. Large animals love to eat fruit and nuts that fall from trees into the water. As this food is very rich in nutrients, the water under such trees is often heavily polluted with putrefactive substances and very low in oxygen. Pacus can withstand this and some species even develop an auxiliary respiratory organ at certain times in the form of a greatly enlarged, very well supplied with blood lip, through which additional oxygen enters the organism when the fish swims on the water surface.

Piaractus brachypomus is relatively unspecialized. It is also found in clean waters and as an opportunist it also eats small fish, shrimps etc., so it is not a pure vegetarian.

Keeping Pacus is easy, but only recommended for people who have huge aquaria. Piaractus brachypomus get on well with each other, but small fish are regarded as food supplements.

For our customers: the animals have code 218501 (4-6 cm) on our stock list. Please note that we only supply the wholesale trade.

Text & photos: Frank Schäfer

Pygocentrus are the most famous and aquaristically most important piranhas. In contrast to all other piranhas, Pygocentrus are always schooling fish. They are less keen on fin pieces of other fish than Serrasalmus and Pristorycon species and with their particularly sharp teeth they can bite whole pieces out of a body. However, the Pygocentrus species are by no means bloodthirsty monsters either, but opportunists that use any food – often of plant origin – that is available.

Pygocentrus cariba is a beautiful species that is regularly found in the trade and represents the shoaling piranhas in the Orinoco. The large humeral spot (= shoulder spot) is typical of the species and is most pronounced in adolescent and young adult fish. Very small animals (under approx. 4 cm in length) do not yet show the humeral spot. Very old animals, like all Pygocentrus species, tend to be very darkly colored, in which case the species can hardly be distinguished. The species name cariba is only available via a caption (which authors before 1993 usually considered insufficient); Fink (1993) revised the genus Pygocentrus and established cariba as the correct species name for the shoal piranha with shoulder spot (principle of the “first reviser”), whereby the name P. notatus, which was previously considered valid, became a synonym.

This piranha usually grows to a maximum length of approx. 25 cm, the largest length stated in the scientific literature is 27.9 cm total length (including caudal fin).

For our customers: P. cariba has the code numbers 292600 (2-4 cm) to 292607 (18-22 cm) on our stock list. Please note that we only supply the wholesale trade.

Text & photos: Frank Schäfer

It’s amazing how many new, attractive tetra species have been discovered recently! Among them is Hyphessobrycon peugeotorum, which was only scientifically described in 2013 under the name H. peugeoti. It originates from the Brazilian state of Mato Grosso (middle drainage of the Rio Juruena, upper basin of the Rio Tapajós). The unusual species name does not refer to the French car builders, but (quotation): “Hyphessobrycon peugeoti is patronymic to the Peugeot family, who invented the Peugeot pepper mill mechanism in 1842 and whose manufacturing business led to the establishment of a carbon sink reforestation project in the fazenda São Nicolau, in central Brazil, and eventually to the discovery of this new species.” According to the rules of zoological naming, in this case (naming after several individuals, not after a single individual) the Latin plural genitive must be chosen for the species name – i.e. the word ending -orum – and not, as happened, the Latin singular genitive ending in -i.

Apart from that, Hyphessobrycon peugeotorum is a beautiful fish that we can offer as offspring. The species grows to a length of 4-5 cm and is completely peaceful. An experience in the photo tank indicates how the animal should be cared for in order to achieve optimum coloration. In our fishhouse, a male showed mating coloration and developed a black caudal fin (in normal coloration, the caudal fin is transparent and colorless). We caught the animal and some conspecifics, put them in the photo tank and waited. It shouldn’t normally take long for the now decolored animal to show mating colors again. Not so! Nine days passed and nothing happened. We warmed the water, added humic substances, fed live food, changed the water – everything you do to get tetras going. Nothing. Then we darkened the tank considerably! And now it worked. Apparently Hyphessobrycon peugeotorum likes it a bit dim. To each his own!

For our customers: the animals have code 261499 on our stocklist. Please note that we only supply the wholesale trade.

Text & photos. Frank Schäfer

PS: As we have learned, an objection was raised against the change of the species name peugeoti to peugeotorum, so that the species is currently more frequently referred to as H. peugeoti again.

The Rainbow Emperor Tetra (Nematobrycon lacortei) is certainly one of the most attractive tetras in South America. Its home is in western Colombia where it is caught in the catchment area of the Rio San Juan. Males and females can be easily distinguished by the color of the iris. Already in small juveniles the males have a red, the females a blue iris.

To the same genus belongs the usually better known emperor tetra Nematobrycon palmeri. Nematobrycon can only be described as schooling fish to a limited extent, since the males at least occasionally defend territories against conspecifics – and this can happen quite violently. Your aquarium should therefore contain structure-forming elements such as roots and large plants.

Emperor tetras can be kept in medium hard water, but for breeding it should be soft and acidic. They will eat almost all offered foods, for a good spawning it is recommended to feed black mosquito larvae (Culex) regularly.

For our customers: the fish have code 272504 on our stocklist. Please note that we supply exclusively to wholesalers.

Photos F. Schäfer, Text K. Diehl