Author Archives: Frank Schäfer

This attractive tetra is native to Peru. So far, it has not been possible to classify it as one of the scientifically described species.  It is the coloration of the 2–3 cm long juveniles—whose vivid orange sheen reminded us of the well-known copper tetra (Hasemania nana)—that led us to initially name them “Hasemania sp. Orange” (our first import was in 2011), fully aware that it is likely not a Hasemania species at all. It is presumably an undescribed Hemigrammus species. However, the taxonomy of South American small characins is currently undergoing such significant changes that it makes little sense to speculate about genus affiliations. A characteristic feature of the species is the red double spot on the caudal peduncle, with another black spot in its center. It lacks a shoulder spot or a longitudinal body stripe, as seen in most species of small characins.

We have never seen these fish larger than 3–4 cm. It has since become known that the fish are caught in the vicinity of the city of Yurimaguas on the Rio Huallaga (Alto Amazonas Province in the Loreto Region, Peru). Perhaps a scientist specializing in tetras will take an interest in these fish and attempt to identify them.

Caring for them is completely straightforward and similar to that of other small characins. It is highly likely that the water in their natural habitat is soft and acidic, but they are highly adaptable to different water compositions in the aquarium. They will eat any ornamental fish food that fits in their mouths. These fish are completely peaceful both among themselves and with other species. In unfamiliar situations, these tetras seek the company of their own kind, so they should generally be kept in groups of 10 or more. The females are stouter and slightly less colorful. We are not aware of any successful breeding attempts, though no surprises are to be expected in this regard. The water temperature can range from 22–28°C.

For our customers: these fish are listed under codes 255452 (2–3 cm) and 255453 (3–4 cm) on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

They still exist—those mythical fish. These are species of which only a very small number of specimens are known, and about which, consequently, very little is known. Leporinus amae undoubtedly belongs to this group of mythical fish. The species was described in 1980 based on eight specimens caught in Brazil. The type specimen comes from the Rio Apuaê, a tributary of the Rio Pelotas, which in turn is part of the Rio Uruguay drainage. Additional specimens come from the Rio Canoas and the Rio Caveiras, which also belong to the Uruguay River basin. Incidentally, Hypostomus luteus was described by the same author in the same paper. The author—Manuel Pereira de Godoy—investigated the effects of dam construction on the fish fauna.

For a long time afterward, nothing more was heard of Leporinus amae. Then, in 2013, the species was rediscovered in the Argentine province of Misiones (also in the Rio Uruguay basin) and described in detail (Almirón et al.). This study also included color photographs of live specimens of this species—which grows to a maximum length of 12–15 cm—that made every fish lover’s heart beat faster. 

Now, another 13 years later, we’ve managed to import five specimens of this legendary species for the first time. There’s a lot—and I mean a lot—of work involved between wanting to see a fish species in person and actually making that wish come true. Sometimes it never works out, and sometimes, as in this case, it takes years. In any case, we’re very excited about the fish. 

We can’t say anything about their social behavior, as we’re keeping these treasures separately for safety reasons. All five fish have a permanently red throat and a red-rimmed mouth, but the red spots on their bellies vary greatly in intensity depending on their mood—ranging from nearly invisible to the deep red shown by our photo model. Four of the fish are 12–15 cm long, and one is 14–16 cm. The latter specimen is thus the largest known individual of this species to date. Of course, we hope that all five will remain together and possibly form the basis of a breeding stock for this spectacularly beautiful species. Unfortunately, however, this is hindered by the very high price being asked for this rarity.

For our customers: the 12–15 cm long specimens have code 265873, and the 14–16 cm long specimen has code 265874 on our stock list. Please note that we supply exclusively to wholesale customers.

References:

Almirón, A. E., Casciotta, J. R., Bruno, M. C., Piálek, L., Doubnerová, K. & O. Říčan (2013): First record and supplementary description of Leporinus amae Godoy, 1980 (Characiformes: Anostomidae) from freshwaters in Argentina. Check List 9(4): 820–822.

Text & photos: Frank Schäfer

An import from southeastern Brazil provided us with, among other things, several specimens of a piranha that has rarely been seen in the aquarium trade to date: Serrasalmus marginatus. In any case, it seems likely to us that this is the species in question, which is widespread in the Paraná-Paraguay and Uruguay river systems. Very similar species include S. irritans from the Orinoco (Colombia and Venezuela)—see https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/serrasalmus-irritans-2/—and the recently described S. magallensi from Bolivia. The newly described S. castellonae—also from Bolivia—looks similar as well. When you consider that the scientific paper describing S. castellonae is 19 pages long, and the description of S. magallensi is 24 pages long—and that’s using scientific language—you can appreciate that many piranha species are incredibly similar to one another, and even scientists require extremely detailed explanations to make the differences reasonably plausible.

For us, it is the combination of origin, body shape, and anal fin coloration that leads us to conclude that our current imports are S. marginatus. In their description of S. castellonae, the authors once again highlight how important caudal fin coloration is for avoiding confusion between closely related species. However, this very characteristic has so far been insufficiently studied in S. marginatus. The species was scientifically named as early as 1837, and there is also a very beautiful, colored illustration of the presumed type specimen. The three original specimens from the Río de la Plata in Argentina, which were collected by d’Orbignyi 1826-1833 and used to describe S. marginatus, are still preserved in the Paris museum. However, the crucial detail—whether the posterior edge of the caudal fin is colorless or black—cannot be determined with certainty from these specimens. Therefore, it is entirely possible that the fish we currently classify as S. marginatus may be reclassified in the future.

Regardless, our specimens are currently 12–15 cm long. We keep them individually, as piranhas in this taxonomic group are considered solitary and fin-nippers. The maximum length for S. marginatus is listed in the literature as 30 cm.

We are pleased to have been able to import these beautiful specimens of a piranha species that is so rarely available. These are, of course, fish intended for specialists and will never gain any significant importance in the aquarium hobby. Nevertheless, they represent a piece of the puzzle that can help expand our still-insufficient knowledge of piranhas.

For our customers: these fish are listed under code 292305 on our stock list. Please note that we supply exclusively to wholesalers.

References:

Gallo-Cardozo, F., M. Maldonado, M. Careaga & F. M. Carvajal-Vallejos (2024): A new species of Piranha (Serrasalmus, Serrasalmidae) from the upper Madeira River system, Amazon basin, Bolivia. Journal of Ichthyology v. 64 (no. 3): 386-409. 

Gallo-Cardozo, F., M. Careaga & F. M. Carvajal-Vallejos (2025): A new cryptic species of Piranha Serrasalmus (Serrasalmidae) from the Bolivian Amazon, upper Madeira River system. Journal of Ichthyology v. 65 (no. 4): 574-592.

Text & photos: Frank Schäfer

There are four species of the small headstanders in the genus Chilodus. In theory, they should be relatively easy to distinguish, since two of these species (Chilodus fritillus from Peru and C. zunevei from French Guiana, Suriname, and the area of Brazil bordering French Guiana) never have a longitudinal band, while the other two (C. gracilis from Brazil and Colombia and C. punctatus from large parts of South America) do have such a band. But in practice, as is so often the case, it’s not quite that simple. This is because Chilodus punctatus can, depending on its mood, show or hide this longitudinal band. Furthermore, C. punctatus, as it is currently defined, looks slightly different depending on its origin—which should come as no surprise to anyone. It is likely that the name “Chilodus punctatus” does not actually refer to a single species with near-universal distribution across tropical South America—it has been reported from Brazil, Bolivia, Ecuador, Guyana, Colombia, Peru, and Suriname—but rather to an entire species complex of very similar species.

Judging by its name, Chilodus punctatus, the spotted head-stander, is the most common species in the hobby. In reality, however, it was seen only quite rarely, at least in the past. Chilodus gracilis, on the other hand, was much more common in the trade, and although the species was not formally described scientifically until 1988, many illustrations in specialized aquarium publications prior to 1950 depict this species. Chilodus gracilis differs from C. punctatus in that it always has a black longitudinal band—it cannot conceal it. This longitudinal band is also relatively wide.

Currently, there are no imports of Chilodus from most parts of South America; instead, almost all fish in the trade are captive-bred specimens from Indonesia. Since these fish have a longitudinal band and can conceal it at least temporarily, they are referred to as Chilodus punctatus. In this post, we show a few wild-caught specimens from earlier years to demonstrate how differently Chilodus can look depending on their mood.

All Chilodus species grow to 8–10 cm in length and should be kept in a school of at least 10–15 fish; otherwise, they tend to be aggressive. Plants are usually nibbled on. You can prevent this somewhat by using only very hard plants (such as Anubias, etc.) and feeding plenty of greens. Blanched land plants like dandelions work best for this. Blanching makes the leaves more tender. You can also freeze them before feeding, which has a similar effect. In addition, you should use plant-based flake food and chips made for L-catfish. The Chilodus’s mouth is made for nibbling; such chips keep the fish occupied and help ensure they don’t get up to mischief by acting on their urge to nibble at the fins of tankmates.

The chemical composition of the water is not critical for keeping Chilodus within the normal parameters for ornamental fish; in nature, the water in their habitats is soft and acidic. The water temperature can range between 22 and 28°C. Chilodus are free-spawning fish that do not care for their young. Males are smaller and slimmer; no other sexual dimorphism is known.

For our customers: The captive-bred Chilodus have codes 217611 (2–3 cm) through 217614 (5–7 cm), wild one have codes 217601 through 217605 on our stock list. Please note that we supply exclusively to wholesalers.

Text & photos: Frank Schäfer

Every now and then, we receive the fantastic Moenkhausia agnesae from Peru. This is a larger species of tetra that, thanks to its hardiness, can be kept successfully with cichlids and catfish. Its maximum length is reported to be about 8 cm.

In the past, this characin species was often confused with Moenkhausia simulata (see https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/moenkhausia-simulata-2/). However, in M. simulata, the horizontal stripes on the body are all blackish, whereas in M. agnesae they are reddish on the back. Hyphessobrycon hexastichos is also very similar (see https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/hyphessobrycon-hexastichos-2/)

For our customers: depending on size, these fish have codes ranging from 268572 (2–3 cm) to 268575 (5–8 cm) on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

We have mentioned this before: identifying Characidium species is a daunting task. A total of 88 species are currently (2026) generally recognized, of which about 30 have been described in the last 10 years. Above all, our knowledge of the “old” species is rather limited. Thus, when importing a new batch, it is never entirely clear whether the fish belong to a previously described species or to a scientifically unknown one. Specifically, we were able to import a cute new bottom-dwelling characin from Peru. No further details are known about the collection site. Overall, surprisingly few Characidium species are known from Peru—only 12: Characidium etheostoma, C. geryi, C. jivaro, C. ortegai, C. pellucidum, C. pteroides, C. pumarinri, C. purpuratum, C. roesseli, C. steindachneri, C. sterbai, and C. zebra.

Our new import matches very well in color to the new species Characidium ortegai, which was published just a few weeks ago. This small species was described from the Ucayali River basin in Peru; the largest specimen known to date has a total length of 43.8 mm (standard length without the caudal fin: 34.8 mm). Unfortunately, there is a catch: a characteristic feature of C. ortegai is the absence of an adipose fin, a rare trait within the genus. In our specimens, however, the adipose fin is clearly present. This leaves three possibilities: 1. Our specimens represent a population of C. ortegai with an adipose fin (such a trait is well known in other characids). 2. They belong to one of the other 12 Characidium species listed above (though most are ruled out because they have a pattern of vertical bands on the body), and 3. Our specimens belong to a new species not yet scientifically described. We have opted for possibility 1, at the risk of having to correct ourselves later—but this risk applies equally to all three options mentioned. To express our uncertainty, we have placed the abbreviation “cf.” between the species and genus names. It stands for “confer,” meaning “compare with.”

In stark contrast to the difficulty of identification, caring for these new small bottom-dwelling tetras is very easy. Our largest specimens—presumably females—are about 3 cm long (total length). At first glance, the pattern appears to consist solely of a dark longitudinal band on a light background; at the base of the caudal fin is the black spot typical of the genus, and all fins are transparent and colorless. However, upon closer inspection, one can see that there are spots within the longitudinal band and, sometimes, thin vertical stripes on the rear half of the body. 

C. cf. ortegai are completely peaceful toward one another and toward fish of other species. They accept any commercially available ornamental fish food of suitable size. Plants are not damaged. We have not observed any special requirements regarding water composition. We keep them at temperatures between 22 and 26°C, at which they appear to be comfortable.

For our customers: these fish are listed under code 215561 on our stock list. Please note that we supply exclusively to wholesalers.

Literature:

Oliveira-Silva, L., R. Britzke, V. Meza-Vargas, M. H. Hidalgo, D. Faustino-Fuster, C. Oliveira & A. M. Zanata (2025): Morphological and molecular evidence reveals a new species of Characidium from the Ucayali-Urubamba Piedmont, Peru, and novel molecular clades are proposed within the genus. Journal of Fish Biology v. 108 (no. 2): 584-595.

Text & photos: Frank Schäfer

The so-called silver hatchet, Gasteropelecus sternicla, is found throughout virtually the entire tropical region of South America. Different genetic lines have likely developed across this vast range. In any case, it is extremely unlikely that this is not the case. Nevertheless, they look remarkably similar everywhere: they are, quite simply, evolutionary success stories! The maximum length of this species is about 6–7 cm.

The photos accompanying this post show fish from Colombia. We almost always have Gasteropelecus sternicla in stock, sometimes also as captive-bred specimens from Indonesia. These Colombian specimens are particularly interesting because these fish originate from the Rio Magdalena. This river, which is about the size of the Rhine, is quite isolated from other river systems in South America, and therefore many of its fish species are found exclusively there; the technical term is: they are endemic to that area. 

In fact, a species of hatchet fish was also scientifically described from the Rio Magdalena in 1912, namely Thoracocharax magdalenae. Today, it is considered a synonym for Gasteropelecus maculatus. Naturally, we were curious to see if the G. sternicla from the Rio Magdalena would look different from their cousins from other regions. Not so! Nevertheless, it was interesting to have seen them once…

Caring for Gasteropelecus sternicla is easy if you follow a few basic rules. Water parameters are not critical. The water temperature should be between 22 and 28°C. The aquarium must be completely covered, as Gasteropelecus are flying fish. In the wild, they feed on small insects, which they leap after. A small mosquito flying through the living room can cause the entire school of hatchet fish to land on the carpet! Additionally, when feeding, keep in mind that hatchet fish only take food from the water’s surface or as it sinks. Since these fish have small stomachs, they should be fed several times a day in small portions (enough to be completely eaten within 5 minutes). Gasteropelecus aren’t very picky about food. Insects (e.g., Drosophila) are their absolute favorite food, but dry food or freeze-dried food is also readily accepted. Gasteropelecus sternicla should be kept in a school. The females are slightly larger and plumper than the males. The gender mix does not matter for their care. Gasteropelecus sternicla are completely peaceful toward conspecifics and other fish species.

For our customers: Depending on size, these animals are listed on our stock list as wild-caught with codes 254401 (sm) to 254407 (xlg) and as captive-bred with code 254412 (sm-md). Please note that we supply exclusively to wholesalers.

Text & photos: Frank Schäfer

Crenuchus spilurus is the only formally described species of the genus Crenuchus. There is, of course, at least one other species in Venezuela (see https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/a_new_species_of_crenuchus__en/). C. spilurus was originally described from the Essequibo River in Guyana. We were able to import some extremely colorful specimens from Peru, which stand out particularly for their vibrant orange hues and the intense red of their fins.

In contrast to almost all other tetras, Crenuchus spilurus is a cave-breeder that also practises broodcare. Unfortunately, breeding is rarely successful. The sexes are easily distinguished by the sail-shaped dorsal and anal fins of the males. In females, these fins are normally pronounced. Despite their large mouths, Crenuchus are peaceful animals. Very small fish are regarded as food, but this applies to almost all fish species.

Crenuchus are quiet creatures that live close to the bottom. Their aquarium should not be too well lit and strong currents should also be avoided. Well-planted, slightly dimly lit tanks with a dark substrate show off the colors of Crenuchus to their best advantage. The males fully deserve their German common name that translates “magnificent tetras” when they show off their widely spread fins. But they don’t do this to order – unfortunately!

For our customers: the animals have code 250245 on our stocklist. Please note that we only supply the wholesale trade.

Text & photos: Frank Schäfer

Since we went online with our homepage over 20 years ago, many new discoveries have been presented here.  Some of them were able to establish themselves as ornamental fish, others disappeared again.The former category includes Hyphessobrycon robustulus, which was initially exported from Peru as “junior tetra”; it is now also regularly bred commercially.The somewhat unusual name comes from the fact that the Peruvian exporter – Jorge Panduro Sr. – handed over the business to his son – Jorge Panduro Jr. – at the time of the discovery of this beautiful tetra. He thought it would be a nice idea to share this with his customers in the form of an interesting novelty. Another popular name for this species is “Panduro tetra” or “Pandurini tetra”, which needs no further explanation after what has been said so far.

Hyphessobrycon robustulus was already described by Cope in 1870 under the name Hemigrammus robustulus. Anatomical features led to its transfer to the genus Hyphessobrycon. The type locality was Pebas in Peru, which at that time belonged to Ecuador. To our knowledge, the “official” assignment of the junior tetra to the species Hyphessobrycon robustulus was made by Zarske in 2007. Previously, another, paler species was listed under this name (e.g. Aquarien-Atlas, Vol. 1, 1990), which was later scientifically described as Hyphessobrycon frankei. 

In general, the name Hyphessobrycon robustulus has become established for the junior tetra. In February 2024 a scientific checklist of all tetra species was published. Here, Hyphessobrycon robustulus is listed as a currently scientifically unclassifiable species (“species inquirendae”), which is only known according to the types from 1870. 

It is therefore not impossible that we will have to retrain at some point. Incidentally, the fishing area for the junior tetra is in the area around Tamishiyacu in the Fernando Lores district of Peru, around 50 km upstream from Iquitos.  

The junior tetra is an ideal aquarium fish, a picture-book tetra. It is small (3.5 – 4 cm), peaceful, colorful and lively. The species makes no special demands on the water composition, the temperature can be between 22 and 28°C. Hyphessobrycon robustulus exhibits an unusually strong sexual dichromatism for characins. All fin parts that are red in the male are yellow in the female.This can be seen particularly well in the video of the species that we have posted on YouTube: https://www.youtube.com/watch?v=JzonUg3cd-s

The pictures for this post show wild-caught specimens that we are once again able to offer.

For our customers: Wild-caught specimens have code 261432, captive-bred specimens code 261423 on our stock list. Please note that we only supply the wholesale trade.

Literature: 

Riehl, R. & Baensch, H. A. (1990): Aquarien Atlas Band 1. 8. Auflage. Mergus Verlag, Melle. page cited: 290

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.

Zarske, A. & J. Géry (1997): Hyphessobrycon frankei sp.n. Die Aquarien- und Terrarienzeitschrift DATZ 50 (5) 1997: 308-312 

Zarske, A. (2007): Hyphessobrycon robustulus (Cope, 1870). Aqaristik Fachmagazin, 198: 26-28

Text & photos: Frank Schäfer

The marbled hatchetfish (Carnegiella strigata) is the ideal aquarium fish. It remains small (4 cm), is peaceful, and has interesting coloration. The species is widespread throughout South America (Brazil, Ecuador, Bolivia, Colombia, Guyana, Peru, and Suriname) and is common. That is why it is almost always available in the ornamental fish trade. 

The distinctive shape of the fish and the variability of their markings have led to several, sometimes conflicting, revisions in the past. Furthermore, there were early instances of misidentification and duplicate descriptions. One thing is certain: the Marbled hatchetfish looks different in its various ranges. In the past, several subspecies were therefore described, such as fasciata from Brazil (Tabatinga), marowini and surinamensis from Suriname, and vesca from Guyana. Currently, however, these subspecies are not scientifically recognized. 

Perhaps the most beautiful—because it is the most striking—variant comes to us from the upper Amazon (Peru and Colombia) and is sold in the trade as “vesca.” The difference between this trade-vesca and “normal” strigata—which were at one time even classified as separate species—lies in the pattern. In strigata, as it is known in the trade, the widest body band forks well below an imaginary horizontal line across the belly to the base of the anal fin, whereas in the trade-vesca, it forks well above this imaginary line. As a result, in this „trade-vesca“, this widest of all body bands is very broad, and the fish appears visually much darker than the strigata form. 

The only problem is that the names are used exactly the wrong way around in the trade. Based on Weitzman’s careful research findings, the dark fish is the “true” Carnegiella strigata, while the “true” vesca is the lighter form, in which the widest body band already forks near the edge of the belly. Regardless of all the confusion: here you will find pictures of the “trade-strigata”: https://www.aquariumglaser.de/en/fisharchive/carnegiella-strigata-lg-xlg-2/; all pictures in this post show “trade-vesca.”

Hatchetfishes are somewhat skittish during the acclimation period and should never be kept with aggressive species. They are ideally suited to being kept with bottom-dwelling fish such as armored catfish. When feeding, ensure that the fish only take food from the surface. Flake food provides a good dietary foundation, but for breeding, you’ll need to put in a bit more effort and feed them small insects such as fruit flies. It is important to feed them several times a day in small amounts. The sexes are not easily distinguishable by appearance, but females grow slightly larger and become rounder around the midsection during the spawning season.

For our customers: these fish have code 214301 (sm) to 214306 (lg-xlg) on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

The real headstander Anostomus anostomus is one of the most beautiful characins in South America. It looks like the big brother of the three-banded pencil fish, Nannostomus trifasciatus. Anostomus anostomus grows to a length of 15–18 cm. Unfortunately, there are currently hardly any exports of ornamental fish from Guyana, which is why the Anostomus anostomus has become a rare sight in aquariums. 

Now we can finally offer captive-bred specimens of these magnificent fish. At a length of about 3–4 cm, they aren’t quite as beautiful as the adults yet, but they’ll get there. The last wild-caught specimens we were able to import in 2018 were young adults and 9–12 cm long; we’ve included photos of these fish in this post for comparison. 

As the first volume of the Aquarium Atlas so aptly puts it: “Anyone who hasn’t kept this fish isn’t a true aquarist!” There’s nothing more to add to that….

For our customers: the animals are listed on our stock list as wild-caught (currently unavailable!) with codes 205501 (3–4 cm) through 205507 (10–12 cm) and as captive-bred (3–4 cm) with code 205521. Please note that we supply exclusively to wholesalers.

Text & Photos: Frank Schäfer

One of the newest stars in the tetra world is the stunning Inapichthys luizae (for more information, see https://www.aquariumglaser.de/en/fisharchive/inpaichthys-luizae-2/). Previously, we sourced these fish from breeders in East Asia; now they are also available as locally bred stock.

For our customers: these fish are listed under code 264792 on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photo: Frank Schäfer

Alestopetersius smykalai is the only species of Congo tetra in the strict sense that does not originate from the Congo basin, but from the Niger. It only grows to a length of about 5-6 cm, which makes it ideal for owners of smaller aquariums. Due to the magnificent blue back of the males, which differ from the females in their long dorsal fin and completely different shaped and white-edged anal fin, the animal has rightly been given the name “Blue Diamond.” 

These fish are easy to care for. Any tap water suitable for drinking is suitable, and the pH value should be approximately neutral. Water measurements on site often reveal surprisingly cool water temperatures of 21-23°C. The temperature in the aquarium can also be slightly higher, but it should not be excessive. A. smykalai is somewhat skittish and should therefore only be kept with calm and peaceful species; for their part, A. smykalai are completely peaceful. Well-planted aquariums with dark bottoms and not too bright lighting bring out the colors of these fish particularly well. They will eat any standard ornamental fish food of a suitable size, but fruit flies (Drosophila) are a particular treat for all Congo tetras. 

For our customers: depending on their size, the animals have codes 100181 (small) to 100184 (large to extra large) on our stock list. Please note that we only supply wholesale customers. 

Text & photos: Frank Schäfer

Traditionally, two species of red-eyed Moenkhausia are distinguished, which are virtually indistinguishable in appearance. These are M. oligolepis from the Amazon region and the Guianas, and M. sanctaefilomenae from the adjacent southern zone, the Rio Paraguay and Parnahyba. There are color-based details for species differentiation, but these are often unreliable. For example, M. oligolepis is also called the “mirror-spot tetra” because the prominent black spot on the base of the tail—which all species in this group possess—is flanked at the front and back by a broad white band. However, this also applies to some M. sanctaefilomenae. A reliable distinguishing feature is therefore that M. oligolepis has more—and thus smaller—scales than M. sanctaefilomenae. In the longitudinal row, M. oligolepis has 29–32 scales, while M. sanctaefilomenae has 22–26. 

But it would be too simple if there were only these two options. In fact, two additional “red-eyed Moenkhausia” species have been described in recent years: M. forestii (2009) and M. pyrophthalma (1994). M. forestii—just like M. sanctaefilomenae—originates from the Rio Paraguay basin and differs only slightly from M. sanctaefilomenae. We quote: “Moenkhausia forestii can be distinguished from M. sanctaefilomenae in the number of transverse series of scales above the lateral line (5, vs. 4 scales, respectively), by the number of transverse series of scales below the lateral line (4, vs. 3 scales, respectively).” All three red-eyed Moenkhausia are currently classified in the genus Bario. In the hobby, M. forestii has likely not yet appeared, or rather, it is very unlikely that it will be recognized as a species distinct from M. sanctaefilomenae. The fourth species, M. pyrophthalma (the species name means “fire eye”), is currently classified in the genus Ramirezella; this fish is much slimmer than those mentioned so far and has a completely different pattern at the base of the tail, making it virtually impossible to confuse.

The most recent research shows that there are actually three species of red eyed Moenkhausia in the drainage of the Rio Paraguay: B. forestii and B. sanctaefilomenae (both with an incomplete lateral line) and B. australis (with a complete lateral line). The latter was described as early as 1908, but it was later believed that the lateral line was variable and unsuitable for species identification.

We are occasionally able to import wild red-eyed Moenkhausia, sometimes M. sanctaefilomenae from Paraguay (see https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/moenkhausia_sanctaefilomenae_wild_en/) and sometimes M. oligolepis from Peru. 

Caring for and breeding both species is easy (probably also for B. forestii and B. australis, if one could obtain them); water parameters play only a minor role. pH levels between 6 and 8, soft to moderately hard water (and even hard water after acclimation), a water temperature between 22 and 26°C as a guideline (it can occasionally be slightly lower or higher), and red-eyed Moenkhausia will thrive. They will eat any commercially available ornamental fish food of suitable size. Red-eyed Moenkhausia should always be kept in as large a school as possible. With a maximum length of 12 cm (total length including tail fin), M. oligolepis grows significantly larger than M. sanctaefilomenae (approx. 7 cm) and is therefore better suited than the latter as a companion fish for larger cichlids, etc.

For our customers: M. oligolepis has – depending on size – code 268902 (md), 268903 (md-lg), and 268904 (xlg) – on our stock list. Please note that we supply exclusively to wholesalers.

Literature:

Mirande, J.M., Körber, S., Terán, G.E. & G. Aguílera (2024): Welche Spezies mit roten Augen ist es? Die Moenkhausia oligolepis Gruppe in Argentinien (Characiformes: Characidae). AKFS-aktuell (49): 23-30

Text & photos: Frank Schäfer

In southwestern Ecuador, on the Pacific side of the Andes, lives the remarkable tetra Rhoadsia altipinna. In terms of coloration, this species—also known as the rainbow tetra—resembles an XXL version of the brilliant tetra, Moenkhausia pittieri. But when it comes to behavior, one can’t help but think that this tetra originally planned to become a cichlid. The males of R. altipinna, recognizable by the red edge on their anal fin and which also develop much larger fins as they age, occupy spawning territories and defend them vigorously. The males even engage in direct brood care (in this case, cleaning debris from the eggs).

Unfortunately, the species has become rare in aquariums, as there are currently no exports from Ecuador. The last imports were so long ago that we had to dig quite deep into the archives to find a few pictures of larger specimens showing the male’s red anal fin edge; unfortunately, this feature develops quite late.

From time to time, we are able to offer a few 4–6 cm long juveniles of this fascinating and magnificent species. Males can reach an impressive maximum length of 17 cm. Females always remain considerably smaller; the literature cites 9 cm. Regarding water parameters (total hardness up to approx. 15°dH, pH 6.3–7.5, 22–25°C), care and breeding are considered easy; spacious aquariums and nutritious food are particularly important. While they generally accept any type of standard ornamental fish food, coarse frozen and live food (especially insects) should not be missing from their diet, particularly if egg production in the female is desired.

For our customers: these fish have code 287602 on our stock list. Please note that we supply exclusively to wholesalers.

Text & photos: Frank Schäfer

There are few species of tetras that have been depicted under incorrect names in the literature as often as those of the genus Mimagoniates. These attractive fish are occasionally exported from southern Brazil as ornamental fish. Since they reproduce via internal fertilization—meaning the female can lay fertilized, viable eggs some time after fertilization even in the absence of males—they piqued the interest of biologically curious aquarists early on. The fertilization process, in particular, aroused and continues to arouse curiosity. 

But the confusion! We don’t want to overcomplicate things here; anyone wishing to delve deeper into the subject should consult the 2009 revision of this group by Menezes and Weitzman. In any case, the animals originally described by Steindachner in 1877 as Paragoniates microlepis have been referred to in the literature as Coelurichthys iporangae (genus name originally misspelled as “Coalurichthys”), C. microlepis, C. tenuis, C. lateralis, Mimagoniates microlepis, M. tenuis, M. inequalis, M. barberi, and M. lateralis. Some of these species actually exist; they look similar but are simply different species, while others are synonyms. The risk of being led in the wrong direction when studying the literature—and even more so when Googling or using AI—is therefore very high. For us aquarists, the combination of a clearly recognizable shoulder spot and the very broad body band is the best identification criterion.

Mimagoniates microlepis grows to about 6–7 cm in length in the aquarium (total length, including the caudal fin); wild specimens remain about one centimeter smaller. They are very lively schooling fish that prefer to live in streams in the wild but have proven to be adaptable. Most often, cool, shaded clear-water streams serve as their habitat, but the fish are also found in blackwater streams and can even adapt to heavily disturbed habitats where humans have destroyed the original “Mata Atlântica” flora. Mimagoniates microlepis has even been documented in stagnant waters. It is widely distributed: coastal area from southern Bahia to northern Rio Grande do Sul and also in the upper rio Iguaçu and rio Tibagi, upper rio Paraná basin, Brazil

In the hobby, such “tail-gland tetras” have been known since 1907. The males possess a complex glandular apparatus at the base of the caudal fin, constructed from scales, which apparently produces specific sexual attractants (pheromones). The courtship is an incomparable spectacle in which the males perform elaborate swimming maneuvers (“mating dances”) in front of the females. During the actual mating, the male wraps himself around the female like a ring. In the process, a sperm packet is expelled, which the female absorbs. Egg laying often occurs only days, and reportedly sometimes even weeks or months later. The female prefers to attach the spawn to the underside of aquatic plant leaves.

Mimagoniates microlepis is a peaceful species that accepts all standard types of food. It is important that the water temperature does not remain too high for extended periods. Temperatures between 16 and 24°C are appropriate, though 18–20°C should be maintained for most of the year. This species would likely benefit from occasional outdoor rearing, but under such conditions, it is unfortunately difficult to observe the fish.

For our customers: these fish have code 268563 on our stock list. Please note that we supply exclusively to wholesalers.

Literature:

Menezes, N. A. & S. H. Weitzman (2009): Systematics of the neotropical fish subfamily Glandulocaudinae (Teleostei: Characiformes: Characidae). Neotropical Ichthyology v. 7 (no. 3): 295-370

Text & photos: Frank Schäfer

Barracuda tetras of the genus Acestrorhynchus are very well suited for aquarium keeping, even though they are true predatory fish and primarily feed on small fish in the wild. Several species grow to a medium size, about 20–30 cm, but there are also dwarf species, including A. isalinae, which reaches only about 7.5 cm in standard length (i.e., about 10 cm in total length; after all, the caudal fin is usually not included in the measurement for fish); Imported specimens sometimes include giants measuring about 12 cm in total length (ie with caudal fin). This species is also the most attractive Acestrorhynchus in terms of body markings: It has two black longitudinal bands and a partially red or yellow caudal base spot; overall, the caudal base spot is divided into three sections. The top section is red or yellow, the middle section is black, and the bottom section is white.

Acestrorhynchus isalinae was first scientifically described in 1983 from the drainage of the Rio Madeira. No exports of the species originate from there, but there is a beautiful book about the fish of the Rio Madeira; the A. isalinae depicted there matches the animals we regularly import from Peru in all color characteristics. As early as 1909, Eigenmann described an extremely similar species from British Guiana, namely Acestrorhynchus nasutus. It is occasionally speculated that A. nasutus and A. isalinae are the same species, or that all fish imported as A. isalinae are in fact A. nasutus.

However, as can be clearly seen in the 1903 photograph of the type specimen of A. nasutus, the black caudal base spot in this species is not punctate as in A. isalinae, but rather diamond-shaped, extending to the end of the caudal fin; Furthermore, in A. nasutus, the ventral stripe ends above the anal fin, whereas in A. isalinae it extends along the entire length of the abdomen. Apparently, A. nasutus has never been imported for the aquarium trade. A. nasutus also grows to only about 7.5 cm in length. Furthermore, the similarly colored A. maculipinna from the Amazon region in Brazil—which also remains small (8 cm without the caudal fin)—has a large black spot at the base of the dorsal fin.

Acestrorhynchus are generally relatively peaceful toward one another and toward other fish that are not potential food sources. However, this must be modified in that it is not advisable to keep specimens of different sizes together in the case of A. isalinae. In this scenario, the larger specimens will bully the smaller ones, even if the size difference is only 1–2 cm. In extreme cases, the bullying can even be fatal, so exercise caution!

The chemical composition of the water is relatively unimportant for A. isalinae; a pH between 6 and 8, water hardness ranging from soft to moderately hard, and a temperature between 22 and 26°C are ideal conditions. Feeding presents a challenge. Live feed fish should be avoided whenever possible, as they can always carry pathogens. Smaller A. isalinae readily eat live white mosquito larvae, for example. With a little patience, the animals can almost always be accustomed to coarse frozen food.

For our customers: the animals have – depending on size – code 202100 (4-5 cm) to code 202104 (9-12 cm) on our stock list. Please note that we supply exclusively to wholesalers.

Literature:

Eigenmann, C. H. (1912): The freshwater fishes of British Guiana, including a study of the ecological grouping of species, and the relation of the fauna of the plateau to that of the lowlands. Memoirs of the Carnegie Museum v. 5 (no. 1): i-xxii + 1-578, Pls. 1-103.

Menezes, N. A. & J. Géry (1983): Seven new acestrorhynchin characid species (Osteichthyes, Ostariophysi, Characiformes) with comments on the systematics of the group. Revue Suisse de Zoologie v. 90 (no. 3): 563-592.

de Queiroz, L. J., Torrente-Vilara, G., Ohara, W. M., da Silva Pires, T. H., Zuanon, J & C. R. da Costa Doria (2013): Peixes do Rio Madeira, Vol 1-3, Sao Paulo

Text & photos: Frank Schäfer

New imports often pose a significant challenge when it comes to identification. A good example of this is the beautiful tetra from Peru, which we were recently able to import again after exactly 25 years, but whose identity remains highly questionable. At the time, based on the available data, we identified the fish as Acrobrycon ipanquianus, an identification that cannot be upheld in light of recent research findings on A. ipanquianus.

At first glance, the small (approx. 3 cm) fish strongly resembles the Blue Peruvian tetra, Knodus borki. At second glance, however, it differs significantly from that species due to its cherry-red adipose fin. The characteristic of a red adipose fin is extremely unusual in characins in general and is displayed by all specimens of the new imports regardless of their mood, making it a species-specific trait in living animals. Unfortunately, red and yellow colors fade very quickly in preserved fish. In scientific species descriptions, such a characteristic is therefore only mentioned if the live coloration is known. However, this is very rarely the case.

The genus Knodus, together with its immediate sister genus Bryconamericus, forms a large species complex. According to Fishbase (accessed on March 18, 2026), 81 species are currently assigned to the genus Bryconamericus, and 29 species to Knodus. There is some overlap between the two. The only difference between Bryconamericus and Knodus is that in Knodus, parts of the caudal fin are scaled, whereas in Bryconamericus they are not. However, there are Bryconamericus species that have a few large scales at the junction between the trunk and the caudal fin. For this reason, some ichthyologists view Knodus merely as a synonym for Bryconamericus. This makes evaluating the literature difficult. There are hardly any live photos of any of the 110 species. Our new import has—clearly visible in some of our photos—quite dense scaling on the proximal part of the lower caudal fin lobe. It is therefore most likely a Knodus, but there is currently no way to definitively identify our new imports.

At the moment, everything points to Knodus sp. “Red Adipose Fin” being either an undescribed species or a member of another characin genus that we are not currently aware of. Even though this is somewhat unsatisfying given the considerable effort we have already put into attempting an identification, we should therefore leave it at the provisional designation Knodus sp. “Red Adipose Fin” for the time being.

Watching this lively and beautiful fish is a lot of fun. It has a remarkable ability to change color. It lacks a humeral spot entirely. Instead, it has a black longitudinal band that runs along the center of the body, starting at the edge of the gill cover and ending at the tip of the caudal fin. The pigment cells containing the dark pigment that form the longitudinal band can be contracted so strongly by the living fish that it appears completely transparent from one moment to the next. The coloration features a beautifully blue-iridescent back and a red adipose fin. Additionally, the anal fin may turn red, and occasionally a red spot appears at the base of the caudal fin. In terms of care, the new Knodus sp. “Red Adipose Fin” proved to be completely trouble-free; they eat all standard foods and show obvious well-being in soft to moderately hard water at 22–26°C.

For our customers: the animals have code 264748 on our stock list. Please note that we supply exclusively to wholesalers.

Text & photos: Frank Schäfer

Anyone who has ever dealt with piranhas and their species identification knows that it is difficult! Piranhas change their coloration significantly over the course of their lives, and in many cases, this coloration also varies individually. The body shape is also subject to ontogenetic changes (ontogenesis: individual development, as opposed to phylogenesis, the phylogenetic, genetically determined development). That is why the history of research on piranhas is full of errors. This applies both to scientific research and, to an even greater extent, to aquarium research. Every new publication brings new insights. And it seems that the description of a new piranha species (Serrasalmus magallanesi) from the upper Rio Madeira system in Bolivia has brought with it the clarification of an old error.

Serrasalmus hollandi is a well-known species that was first described in 1915 from the Rio Guaporé near the city of Maciél in Brazil. The Rio Guaporé is known to be the border river between Brazil and Bolivia (where it is called Rio Iténez), so the first describers also had to redefine S. hollandi in order to distinguish their new species from the well-known one. 

In aquariums, several piranha species have been identified as S. hollandi: erroneously, it seems. The “real” S. hollandi is a blunt-snouted piranha that is extremely similar to S. humeralis, S. eigenmanni, and S. serrulatus, and some age classes of S. gouldingi also look very similar. Based on the latest findings, it can be assumed that all piranhas from Peru previously referred to as “S. eigenmanni” are actually S. hollandi. S. eigenmanni is only found in Guyana.

Serrasalmus hollandi reaches a body length of around 20 cm. The species is considered a specialized fin eater, which means it is difficult to keep in groups, as even conspecifics are generally regarded as a food source. Since such piranhas are only kept by specialists and research institutions, further information on keeping them in aquariums is unnecessary at this point.

For our customers: S. hollandi has code 292200 (2-3 cm) to 292205 (12-15 cm) on our stock list. Animals currently imported from Peru are listed under “cf. hollandi” with the code numbers 292212 (4-6 cm) and 292213 (7-10 cm). Please note that we only supply wholesale customers.

Literature:

Gallo-Cardozo, F., M. Maldonado, M. Careaga & F. M. Carvajal-Vallejos (2024): A new species of Piranha (Serrasalmus, Serrasalmidae) from the upper Madeira River system, Amazon basin, Bolivia. Journal of Ichthyology v. 64 (no. 3): 386-409

Text & photos: 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