Author Archives: Frank Schäfer

The tetras belonging to the genus Pyrrhulina combine the advantages of two basic groups of ornamental fish. The first group are the schooling species that are always visible and swim merely in the open water: tetras and barbs. The second group has a faszinating behaviour and takes care for the brood: the cichlids and the labyrinth fish. 

One of the most beautiful Pyrrhulia species is P. spilota, which we are able to import from Peru from time to time. P. spilota usually swim around in open water, as is typical for tetras. They prefer the upper third of the water column, but can be found everywhere. They eat all types of fish food, including dry food, and leave the plants untouched. In this respect, their behavior is largely similar to that of other tetras.

When the animals enter breeding season, everything changes. During this time, the males develop fantastic colors and occupy territories, preferably near a broad-leaved plant, or, if necessary, near a stone or root. This is where the fish lay their eggs. Unlike other tetras, which scatter their eggs indiscriminately, Pyrrhulina produce a compact clutch that is very similar to a cichlid clutch. At this time, there is no male that does not have slightly damaged fins from fights with other males. This is part of the process, completely normal and harmless. Once the spawning season is over, everything grows back.

As with labyrinth fish, the male takes care of the brood. And he takes his task very seriously! Any tank mates would be well advised not to get too close to the clutch. Once the young hatch, the brood care instinct disappears and Pyrrhulina return to being normal, beautiful tetras…

For our customers: P. spilota has code 286782 to 286785 on our stock list, depending on size; the fish are usually sent to us in mixed sizes. Please note that we only supply wholesale customers. 

Text & photos: Frank Schäfer

The classification of the genus of African alestid characins is the subject of ongoing debate, with no end in sight. There is constant back and forth, especially with regard to the Congo characins, which are of some importance in aquariums. Just recently, in the latest checklist of characins (Toledo-Piza et al, 2024), P. bleheri, which at first glance is very similar to the “normal” Congo tetra (Phenacogrammus interruptus), was listed in the genus Alestopetersius. There are currently 12 accepted species in Alestopetersius. Many are very similar to each other and difficult to identify. A. smykalai from the Niger is easily recognizable, but the species from the Congo – all the rest – are very tricky. Males in breeding coloration are characterized by their coloring, but it can take several weeks to months for them to get into the mood for breeding. For understandable reasons, we cannot wait that long in the trade.

We recently received a shipment of Congo tetras from the Congo labeled “Alestopetersius brichardi.” This species does exist, and a quick Google image search using this name returned our fish among the results. In the meantime (after 10 days), some of the males have changed color, causing us to have serious doubts. Fortunately, the last revision of all Alestopetersius species was not long ago; it was carried out in 2012 by Mbimbi Mayi Munene & Stiassny on the occasion of the description of a new species. According to this, A. brichardi is a slender fish with a broad black longitudinal band that extends to the end of the caudal fin. A. leopoldianus (https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/alestopetersius-leopoldianus-2/) is very similar. Our fish, on the other hand, has a significantly higher back, the longitudinal band (which is only visible in certain lighting conditions) is much narrower, and there is a vertical humeral spot on the shoulder, which is absent in A. brichardi.

We have decided to leave our new import without a “proper” name and instead name it after the location where it was found. According to the supplier, these animals were caught in the Kwilu River, one of the larger tributaries of the Kasai River, not far from the city of Bandundu in the province of the same name in the DR Congo. In a scientific collection published in 2011 (Mbimbi Mayi Munene & Stiassny, 2011), two Alestopetersius species from the Kwilu are reported: the newly described A. conspectus (this species differs from all other A. species in, among other things, a striking flag pattern on the caudal fin) and A. sp. “mbuji”; unfortunately, the latter species was only available in one specimen that was not described in detail, but DNA analysis showed that it is a new species not yet recorded scientifically. Of the species described, the similarity to A. bifasciatus seems greatest to us due to the high proportion of black coloring in the caudal fin.

Such novelties are relatively expensive for several reasons, and debates about who is right in determining and naming them are counterproductive for the spread of the animals in the hobby, as there is always the underlying suspicion that someone in the commercial chain of catcher-buyer-exporter-importer-wholesaler-retailer has fraudulent intentions. Without a doubt, the newly imported Alestopetersius sp. “Kwilu-Bandundu” are beautiful fish. We can only advise anyone interested in African characins to grab them while they can, as it is highly uncertain when and if another import of these fish will be successful.

Our specimens have proven to be robust and healthy so far. The alpha male photographed (recognizable by the white fin edges) is approx. 5.5 cm long (including tail fin), so Alestopetersius sp. “Kwilu-Bandundu” seems to remain relatively small (although the animals will probably grow another one to two centimeters). They adapt well to life in an aquarium. From experience with other Congo tetras, we know that only soft, slightly acidic water is required for breeding. The only Alestopetersius firmly established in the hobby is the yellow Congo tetra (A. caudalis), which is now almost exclusively offered as a captive-bred species. For more information on this species, see: https://www.aquariumglaser.de/en/fisharchive/alestopetersius-caudalis-4/.

The new Alestopetersius sp. “Kwilu-Bandundu” is completely peaceful. It should be kept in as large a group of conspecifics as possible in a densely planted aquarium that also provides enough swimming space, with lighting that is not too bright. Any drinking water is suitable for keeping them. However, experience has shown that Alestopetersius develop their fins most beautifully in soft, slightly acidic water (pH around 6). The temperature should be between 22 and 28°C. They will eat any food of animal origin, whether dry, frozen, or live. The animals particularly enjoy being fed small fruit flies (Drosophila), a trick used by breeders to achieve the most abundant spawning possible in female A. caudalis.

For our customers: Alestopetersius sp. “Kwilu-Bandundu” has code 100193 on our stock list. Please note that we only supply wholesale customers.

Literature:

Boden. G. in Toledo-Piza, M., E. G. Baena, F. C. P. Dagosta, N. A. Menezes, M. Ândrade, R. C. Benine, V. A. Bertaco, J. L. Birindelli, G. Boden, P. A. Buckup, P. Camelier, F. R. Carvalho, R. M. C. Castro, J. Chuctaya, E. Decru, E. Derijst et al. (2024): Checklist of the species of the Order Characiformes (Teleostei: Ostariophysi). Neotropical Ichthyology v. 22 (no. 1): e230086: 1-548.

Mbimbi Mayi Munene, J. J. & M. L. J. Stiassny (2011): Fishes of the Kwilu River (Kasai basin, central Africa): A list of species collected in the vicinity of Kikwit, Bandundu Province, Democratic Republic of Congo. Check List 7 (5): 691-699

Mbimbi Mayi Munene, J. J. & M. L. J. Stiassny (2012): A new Alestopetersius (Characiformes: Alestidae) from the Kwilu River (Kasai basin) of central Africa; with a phylogeny for the genus and synonymy of Duboisialestes. Zootaxa No. 3166: 59-68.

Poll, M. (1967): Révision des Characidae nains Africans. Annales, Musée Royal de l’Afrique Centrale, Tervuren, Série in 8o, Sciences Zoologiques No. 162: 1-158.

Text & photos: Frank Schäfer

In 2008, while examining a newly imported species (previously referred to by us as Boehlkea sp. “Sky Blue”), Dr. Axel Zarske discovered that it was actually Boehlkea fredcochui. The fish that had been referred to as B. fredcochui for decades, on the other hand, represented a species of the genus Knodus that had not yet been scientifically recorded and was described as Knodus borki in honor of Dieter Bork.

The common name Blue Peru Tetra has remained. The animals were first imported around 1956. The location “Leticia” (Colombia) referred to at the time was the city from which the export took place. To this day, Leticia, located in the border triangle of Peru, Brazil, and Colombia, is one of the most important trading centers for ornamental fish in the Amazon region. Many rarities are even shipped exclusively via Leticia, even though they come from relatively distant areas, simply because Leticia has the infrastructure that makes it possible to market the animals. In fact, Knodus borki occurs in the vicinity of Iquitos. In the hobby, the blue Peru tetra is part of the standard range. It is available all year round, mostly as a captive-bred specimen, but occasionally also as a wild catch. There is also an albino breed.

Knodus borki grows to a length of 4-5 cm (total length, including tail fin) and is a very peaceful, highly active schooling fish. Plants and any other inhabitants of the aquarium are not disturbed. These lively animals are easy to care for. They should be kept in groups of at least 10. Their somewhat “hanging” swimming style is typical of the species. It is not as extreme as that of the Penguin tetras, but it is particularly noticeable when the fish pause briefly (and the photographer can focus and take a picture). Any tap water suitable for drinking is suitable for keeping these fish, and the water temperature can be between 22 and 26°C. They will eat any commercially available ornamental fish food of a suitable size. Males and females differ only slightly in color, but the light areas at the tips of the tail fin are more pronounced in males. They are open spawners without brood care.

For our customers: depending on size, the animal has code 210001 to 210004 (wild catch) and 210011 to 210014 (captive bred) on our stock list. The “real” Boehlkea fredcochui, which is very rarely found in the trade, has code 210051 to 210053. Please note that we only supply wholesale customers.

Text & photos: Frank Schäfer

Since 2018, a relatively small species of tetra from the central Congo Basin has been causing quite a stir: Phenacogrammus sp. “Fantastique.” However, very little literature has been published on these animals to date, which is somewhat surprising given their small size (for an African alestid) and the beautiful coloration of the males, at least at certain times. To our knowledge, these animals have not yet been scientifically studied. Even their classification in the genus Phenacogrammus is questionable, as the generic classification of African small tetras has always been the subject of controversial debate among ichthyologists. 

The externally recognizable species-specific characteristics of Phenacogrammus sp. “Fantastique” are—apart from the magnificent coloring of males during courtship, which they only display after a long period of acclimatization—a slender build, a clearly pronounced shoulder spot ( = humeral spot), black-colored middle rays of the caudal fin in males, in large males these black-colored middle caudal fin rays protrude beyond the rear edge of the caudal fin in the form of a thread-like extension, and, as an important, albeit inconspicuous feature at first glance, a clearly visible white spot on the adipose fin. Taking all these characteristics and the origin (central Congo Basin) together and assuming that this is a species that has already been scientifically recorded, there is much to suggest that Phenacogrammus sp. “Fantastique” is identical to P. deheyni. Just recently (2021), two similar Congo tetras from the central Congo Basin were newly described, namely Phenacogrammus flexus and P. concolor. In the course of distinguishing these two new species from the already known species, the four other species known from the central Congo Basin (P. polli, P. deheyni, P. aurantiacus, and P. interruptus) were also reviewed; Based on this work, it can be ruled out that Phenacogrammus sp. “Fantastique” is identical to any species other than P. deheyni and P. concolor. Unfortunately, the live coloration of P. concolor is unknown. Therefore, it is better to stick with Phenacogrammus sp. “Fantastique” as the name for aquarium imports for the time being.

Due to the complex political situation in Congo and major logistical problems there, Phenacogrammus sp. “Fantastique” is a very rarely imported fish that is also expensive. Like so many Alestidae, the species is also sensitive to transport. Any transfer should be carefully considered. The animals always take quite a long time to acclimatize and are naturally susceptible to disease during this period. The location where it was found is described as follows: a cola-colored, shallow forest stream that flows into the Likouala. Very soft, acidic water (pH 4.5, conductivity 15 µS/cm), water temperature around 24°C at 11.30 in February (dry season), light sandy bottom, wood deposits and dead leaves, no underwater plants. During the dry season, the animals swim in schools of 30-50 specimens (Numrich, 2018).

According to information on the internet, which we cannot verify, the maximum length of Phenacogrammus sp. “Fantastique” is said to be around 8 cm (this probably refers to the total length, i.e. including the tail fin), while Numrich (2018) gives a length of 6 cm. The maximum length of P. deheyni is given as almost 10 cm in aquarium literature, but the adult specimens described in scientific literature were only 5-6 cm long (including the tail fin), and both P. flexus and P. concolor have a standard length (without tail fin) of less than 5 cm. The animals photographed for this post are about 5 cm long, including the tail fin, and have just reached sexual maturity. “Fantastique” is therefore a small fish.

Unfortunately, we have not yet been able to observe the bright red coloration that the males display during the mating season. But this is well known in tetras, just think of Hemigrammus coeruleus (https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/hemigrammus-coeruleus-4/). In their normal coloration, males appear orange-copper with reddish fins and two deep red spots on the caudal fin; females are more plainly colored. In terms of social behavior, feeding habits, etc., we have not yet noticed any differences from the well-known Congo tetra (P. interruptus). We therefore refer you to the extensive literature on this fish.

All in all, Phenacogrammus sp. “Fantastique” is an exciting new addition that we hope will become widely distributed!

For our customers: the animals have code 159102 on our stock list. Please note that we only supply wholesale customers.

Literature:

Numrich, R. (2018): Kongosalmler aus dem Herzen Afrikas. Amazonas Heft 75 (14) 1: 20-27

Poll, M. (1945): Descriptions de Mormyridae et de Characidae nouveaux du Congo belge avec une étude du genre Stomatorhinus et des genres de Characidae nains africains. Revue de Zoologie et de Botanique Africaines v. 39 (no. 1): 36-77

Stiassny, M. L. J., Alter, S. E., Monsembula Iyaba, R. J. C. and T. L. D. Liyandja (2021): Two new Phenacogrammus (Characoidei; Alestidae) from the Ndzaa River (Mfimi-Lukenie basin) of Central Africa, Democratic Republic of Congo. American Museum Novitates No. 3980: 1-22

Text & photos: Frank Schäfer

In 1992, W. L. Fink and A. Machado-Allison described two piranha species of the genus Pristobrycon from locations in the Rio Atabapo basin (Venezuela): P. careospinus and P. maculipinnis. The two species differ in color. While P. maculipinnis has small dots on its body and spots on its vertical fins, the fins of P. careospinus are unmarked and the spots on its body are large. Unfortunately, the scientists only had a few specimens at their disposal. They had six specimens of P. maculipinnis and only one of P. careospinus. This is naturally problematic given the well-known color variability of piranhas and the equally notorious color changes these fish undergo during their growth (scientifically known as ontogenetic color change). 

In 2006, piranhas from Venezuela with very impressive colors appeared on the ornamental fish market for the first time. At that time, they were identified as Pristobrycon maculipinnis, and it was considered likely that P. maculipinnis and P. careospinus were the same species.

We have finally succeeded in importing these beautiful piranhas again, this time four specimens. We now consider the Pristobrycon imported in 2006 and those recently reintroduced to belong to the species P. careospinus and believe that the earlier assumption that P. careospinus and P. maculipinnis were identical was incorrect.

The difference between Pristobrycon and other piranha genera is not visible externally. It is a bone feature, namely the palate (referred to in scientific publications as the palatine or ectopterygoid). This is toothed in typical Serrasalmus species, smooth and toothless in Pygocentrus species, and rough and toothless in Pristobrycon species. Recent molecular biological studies no longer classify P. careospinus in the genus Pristobrycon, but rather in Serrasalmus. The species may therefore be called Serrasalmus careospinus.

Virtually nothing is known about the behavior of this species. In nature, it apparently occurs mostly singly. In aquariums, piranhas are often notorious fin biters, which can make it necessary to keep them singly. On the other hand, Oliver Lucanus (verbal communication) kept a group of the beautiful species we are presenting here, under the name of P. maculipinnis, together for at least a while. Overall, representatives of the genus Pristobrycon (in the conventional sense) are only very rarely kept in aquariums, which is a pity, as all species usually remain under 20 cm in total length and some are very attractively colored. Detailed care reports are lacking in the aquarium literature, not to mention breeding reports. 

The pictures show specimens from the 2006 import and a collage of the four animals that have just arrived in our fishhouse, which naturally still need to recover from the stresses of transport, but are obviously in perfect health.

For our customers: the animals have code 283285 on our stock list. Please note that we only supply wholesale.

Text: Frank Schäfer, photos: Frank Schäfer & Erwin Schraml

The three-banded flag tetra, Hyphessobrycon heterorhabdus, was once one of the most sought-after small tetras. When tetras were very fashionable – in the 1950s to 1970s – this species was classified as a “problem fish” because it did not reproduce without tricks and gimmicks. However, keeping this species without breeding intentions was completely problem-free. Today, we know of a whole complex of three-banded flag tetra species, and identifying them is anything but easy. It is likely that the animals kept at that time were not H. heterorhabdus at all. More information on this can be found here: https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/hyphessobrycon-heterorhabdus-2/

However, a very closely related species of this three-banded flag tetra is fairly easy to identify: Hyphessobrycon amapaensis, the Amapa three-banded flag tetra. This species was caught and brought back from Brazil during an ornamental fish expedition by Bitter and Hessfeld, which was still legally possible at the time (1997). A year later, it was scientifically described as a new species by Zarske and Gery. It was found in a savanna stream on the B156 in the state of Amapa. The water there was clear, slightly brownish, slightly acidic (pH 5.8 to 6.3), very soft (both KH and GH below 1° dH, conductivity 9-13 µS/cm) and around 25-27°C warm. The most interesting accompanying fish was Hyphessobrycon takasei (https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/hyphessobrycon-takasei-2/).

The distinguishing feature of Hyphessobrycon amapaensis is the black section of the longitudinal stripe. In all three-striped flag tetras in the narrower sense, the longitudinal stripe consists of three differently colored, parallel stripes: one red, one light, and one black. In contrast to all other three-banded flag tetras, the black band of Hyphessobrycon amapaensis is greatly widened immediately behind the gill cover to the end of the pectoral fins and also extends into the caudal fin. The uppermost band is coral red and much clearer than in other three-banded flag tetras. To identify the species with certainty, you need to take your time. Depending on its mood, each fish can strongly contract the body cells that contain the black pigment – then the fish becomes light in color and the black markings almost invisible – or expand them. This is what makes the very rapid color change that so many fish exhibit possible. When Hyphessobrycon amapaensis is frightened, the black longitudinal band is often not easily recognizable.

Hyphessobrycon amapaensis is the only species of all three-banded flag tetras to have gained a firm place in the hobby. It is available in good quality as offspring in various sizes almost all year round, although its breeding still requires an experienced tetra breeder even today. Wild-caught specimens only come onto the market very sporadically. The pictures show captive-bred specimens in the md-lg size class. It is an ideal fish for well-maintained community aquariums. Soft, slightly acidic water is favorable for optimal coloration, but the fish are highly adaptable and practically any tap water is suitable for their care. The species is completely peaceful towards conspecifics and non-conspecific fish, and should be kept in a school. The maximum length is about 4 cm. They eat any commercially available ornamental fish food of a suitable size.

For our customers: depending on size and origin, the animals have the codes 259452 (breeding sm-md), 259453 (breeding md-lg), 259454 (breeding lg), 259463 (wild lg), and 259464 (wild xlg) on our stock list. Please note that we only supply wholesale customers.

Text & photos: Frank Schäfer

A pretty new tetra is Inpaichthys luizae, a species that was only formally described in January 2025. It occurs in areas that are hardly accessible to scientists and commercial fishermen because they are privately owned. What is known, however, is that these locations are tributaries of the Rio dos Peixes in Brazil, which in turn is a tributary of the Rio Juruena. The entire area belongs to the Rio Tapajós basin.

This fish first became known in the hobby at the end of 2023. At that time, it was referred to as Inpaichthys sp. “Black Arrow”. As with many new species, only a few specimens initially came onto the market at comparatively high prices; low three-digit euro amounts per specimen were demanded. However, it quickly became apparent that this species is just as productive and easy to breed as its well-known cousin Inpaichthys kerri, the royal tetra. At present (January 2026), the fish are still not cheap, but they are not unaffordable either. We source them as offspring from East Asia.

The sexes of these cute animals, which according to scientific descriptions reach a standard length of about 4 cm (i.e., without the tail fin), are quite easy to distinguish due to the stronger red coloration of the fins in males. This color is already clearly visible in adolescent animals. It can be assumed that aquarium specimens grow 1-2 cm larger than wild-caught fish, a phenomenon that can be attributed to the much better food supply for aquarium fish and, of course, the considerably higher age that fish in aquariums reach compared to wild specimens.

So far, the animals have proven to be absolutely typical small tetras, which do not differ from the royal tetra, Inpaichthys kerri, in terms of aquarium requirements. A very interesting phenomenon with I. luizae is the fact that most specimens have an adipose fin, but some do not. The absence of an adipose fin is very unusual in tetras; at the time, the presence of an adipose fin was one of the reasons for establishing the genus Inpaichthys, as otherwise it is very similar to the genus Nematobrycon (emperor tetras). All Nematobrycon species, without exception, lack the adipose fin. However, there are also specimens of I. luizae without adipose fins, but they are in the minority.

For our customers: the animals have code 264792 on our stock list. Please note that we only supply wholesale customers.

Text & photos: Frank Schäfer

In 2002, a deep red dwarf pencil fish from Peru was imported under the names Nannostomus marginatus “Purple” or N. marginatus “Red.” Axel Zarske from the Senckenberg Natural History Collections Dresden, Museum of Zoology formally described this species in 2009 as Nannostomus rubrocaudatus. We had imported the type specimens on which the scientific description is based from Peru.

At first glance, the new species resembles the already known N. mortenthaleri (see https://www.aquariumglaser.de/en/fisharchive/nannostomus-mortenthaleri-2/), but can still be easily distinguished from this species. N. mortenthaleri, for example, always has a white belly. Further species characteristics are listed in the scientific description. The scientific first description is available as a free download at https://www.senckenberg.de/wp-content/uploads/2019/08/02_vertebrate_zoology_59-1_zarske.pdf.

Nannostomus rubrocaudatus does not exhibit very distinct sexual differences. The intensity of the red coloration varies greatly depending on mood. However, females never turn as red as males. What is particularly tricky is that males low in the hierarchy can fade significantly and camouflage themselves as females in terms of color; females can only be reliably identified by their differently shaped anal fins.

The maximum size of this species is around 3-3.5 cm. It is easy to care for, but should not be kept in small aquariums, as the males fight their rivals quite fiercely and the weaker specimen needs space to escape. If this is not available, damage may occur.

The natural range is in Peru, Dep. Loreto. Here, the species is collected for export near the village of Saramirisa on the Maranon (the upper Amazon) between the tributaries Rio Morona and Rio Santiago. The relatively high price of the fish is explained by the fact that the animals live among dense branches in the wild and have to be laboriously picked out individually. Mass catches, as with other Nannostomus species, where thousands of specimens can easily be caught with a net, are not possible with N. rubrocaudatus.

For our customers: Nannostomus rubrocaudatus has – depending on size – code 272261 (sm) to 272265 (lg-xlg) for wild-caught specimens and 272272 for captive-bred specimens on our stock list. Please note that we only supply wholesale customers.

Text & photos: 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