Author Archives: Frank Schäfer

We believe that a shipment of ground tetras (Characidium) from Colombia consists mainly (though there are a few bycatch specimens among them) of the species Characidium etheostoma, which was first described as early as 1872. This is one of the 17 Characidium species currently reported from Colombia. The coloration of our fish matches the original description very closely. However, because there are always uncertainties when identifying Characidium species, we are cautiously naming these fish Characidium cf. etheostoma (cf. stands for “confer,” which is Latin for “compare with”).

They are very interesting, attractive fish that, like all Characidium species, can be unreservedly recommended for enlivening the bottom zone of the aquarium. The fish are completely peaceful and exhibit very interesting behavior. The species has been reported from large parts of the Amazon basin: Ecuador, Peru, Brazil, and Colombia.

Maximum size: approx. 5 cm; Temperature: 22–28°C; pH and hardness: not significant for care (tap water), likely soft and acidic for breeding; Diet: omnivorous; Social behavior: peaceful fish with a social hierarchy.

For our customers: These fish are listed under code 215572 on our inventory list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

Traditionally, only two Chalceus species have been distinguished: one with a shoulder spot (C. erythrurus) and one without (C. macrolepidotus). When sexually mature, the species with a shoulder spot develops yellow pelvic fins—at least the females do. This classification has often led to confusion in the trade, as there are clearly more Chalceus types that can be distinguished by color. In 2004, a scientific revision of the genus was published, which concluded that there are not just two, but five Chalceus species. The three species newly described in that revision are C. spilogyros, C. guaporensis, and C. epakros; the validity of C. erythrurus and C. macrolepidotus remained unchanged. Unfortunately, the scientists had access almost exclusively to preserved specimens. This makes identification based on color characteristics—which is the only method available in the aquarium hobby—quite challenging, especially since the animals change their coloration over the course of their lives. Juveniles are considerably less conspicuous than sexually mature specimens.

The newly described C. epakros grows to 17.5 cm in length and is found in the Amazon Basin, the Orinoco River basin, and the Essequibo Basin in Guyana. The fish have a faded, indistinct shoulder spot and an equally indistinct longitudinal band extending from the gill cover to the base of the tail; both of these characteristics are much more clearly visible in preserved specimens than in live ones. This is because the color cells (chromatophores) responsible for the shoulder spot and longitudinal band are located deep within the skin in this species.

We occasionally have C. epakros from Colombia in stock. These are very beautiful fish. Members of the genus Chalceus can be compared quite well to our native trout. Similar to trout, Chalceus prefer to feed on surface-falling prey—that is, insects, etc., that fall onto the water’s surface. And—if the information in the literature is to be believed (we don’t eat the fish we keep)—these fish have the most delicious flesh imaginable, even tastier than that of trout.

From an aquarium-keeping perspective, these magnificent creatures need large tanks where they can fully grow to their potential. The fish prefer relatively strong currents, especially in spots that are slightly shaded from above. You should always try to keep 10 or more of them; otherwise, they can become quite quarrelsome with one another.

To other fish, Chalceus are generally peaceful, and they do not bother plants either. Keep in mind that Chalceus are excellent jumpers; therefore, the aquarium must always be securely covered.

For our customers: Chalceus epakros has code 215104 on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos. Frank Schäfer

The Serpae tetra (currently Megalamphodus eques, formerly Hyphessobrycon eques, and previously known as H. callistus or H. serpae) is one of the standard fish available at pet stores. They are, after all, beautiful fish with a crystal-red color. Since the 1930s, there has been considerable confusion regarding the correct classification of the various variants. Even wild Serpae tetras exhibit considerable variation within the same population. Only relatively few wild specimens consistently display the coveted blood-red coloration; many are normally brownish or greenish and turn red only during the breeding season. However, through careful selective breeding, it is possible to very quickly obtain genetically pure, color-stable forms of the Serpae tetra. These have been given various names within the hobby. The brownish-green variety with a relatively small, comma-shaped shoulder spot was called Hyphessobrycon serpae; the red variety with a large, comma-shaped shoulder spot was called H. callistus; a translucent-red form with a small, round shoulder spot—which also lacks the black edge on the anal fin—was called H. minor; however, modern “minor” strains usually do have a black anal fin edge. In addition, since at least the 1980s, there has also been a form known as “Brillant.” It matches the coloration of the old “minor,” but also has glittering scales, especially on the back. And, of course, there are also veil-type varieties… From a current scientific perspective, they are all the same species, namely M. eques.

Since all these fish can interbreed freely, just about every breeding facility has its own “house strain”; wild-caught specimens appear on the market only very sporadically and in small numbers. There is no trademark protection for common fish names, so anyone is free to name their Serpae tetras as they please. This sometimes makes it difficult—and sometimes even impossible—to find a specific variant in sales listings.

All Serpae tetras are very attractive and easy to care for, but they also have an unpleasant trait: during their constant rivalries (which are, however, very beautiful to watch), they tend to ruffle each other’s fins—after all, Serpae tetras are, in a sense, small relatives of piranhas. It is therefore quite rare for all the fish in the aquarium to have undamaged fins at any given time. However, this fin damage is harmless and heals quickly. Serpae tetras should always be kept in as large a group as possible (10 or more). If this rule is not followed, they will pick fights with other fish and can even become true tyrants in the aquarium.

Maximum size: approx. 4–4.5 cm; Temperature: 18–28°C; pH and hardness: not important for keeping (tap water), soft and acidic for breeding; Diet: omnivorous; Social behavior: schooling fish with a social hierarchy.

For our customers: the “callistus” Serpae tetra has code 259792–259793, the “minor” Serpae tetra has code 259801–259804, the “serpa” Serpae tetra has code 261901–261905, the “Brillant” Serpae tetra has codes 261921–291924, veil forms have codes 261952–261955, and the wild M. eques has codes 261932–261933 on our stock list. Please note that we supply exclusively to wholesalers.

Text & Photos: Frank Schäfer

The stream of new tetra species shows no signs of slowing down. Among the current “hottest things in town” is this tetra, which grows to about 5 cm in length and has been designated Moenkhausia sp. “Mystic Blue.” The origin of these fish, which were originally imported from Brazil, is still a matter of speculation. There are reports linking them to the Rio Juruena, one of the two headwater rivers of the Rio Tapajós. Several other new tetra species also come from that area. The fish we offer, however, are German-bred specimens. The species has proven to be quite easy to breed.

Their coloration is particularly mystical, as the fish can look quite different depending on their mood and in response to the prevailing lighting conditions. To capture the blue well in the photo, we had to photograph them in the holding tank at our facility. In the photo tank, they displayed more reddish tones. The orange neck spot of Moenkhausia sp. “Mystic Blue” serves as a relatively reliable distinguishing feature from the very similar-looking Hyphessobrycon cyanotaenia and H. melanostichos. The two Hyphessobrycon species mentioned never display this spot. Furthermore, “Mystic Blue”—whose classification within the genus Moenkhausia is, incidentally, questioned by tetra specialist Martin Hoffmann—is much sturdier and has a higher back as an adult, and its blue is a very strikingly bright blue.

There are two color variants of Moenkhausia sp. “Mystic Blue”: one with a red caudal fin and one with a yellow caudal fin. The fish we offer belong to the red-tailed color variant.

Maximum size: approx. 5 cm; Temperature: 22–28°C; pH and hardness: not important for general care (tap water), but should be soft and acidic for breeding; Diet: omnivorous; Social behavior: generally peaceful schooling fish, but needs space; otherwise, males engaged in courtship displays can become a nuisance.

For our customers: These fish are listed under code 269492 on our stock list. Please note that we supply exclusively to wholesalers.

Text & photos: Frank Schäfer

Identifying Serrasalmus species is one of the most challenging aspects of ichthyology. Knowing the species’ origin is therefore particularly important for Serrasalmus species if one wishes to identify them with any degree of certainty. Two piranha species of the genus Serrasalmus are currently known from Paraguay: S. maculatus and S. marginatus. They differ in body shape. While S. maculatus is a piranha with a fairly rounded back and blunt snout as an adult, S. marginatus belongs to a group of species with a front portion of the back that can almost be described as concave and a pike-like head. You can find pictures of S. marginatus here: https://www.aquariumglaser.de/en/fisharchive/serrasalmus-marginatus-2/

In the wild, Serrasalmus maculatus feeds primarily on the fins of other fish. Although it quickly adapts to a varied diet in the aquarium—such as frozen fish, shrimp, live earthworms, etc.—it never stops biting fins. This behavior also extends to members of its own species. For this reason, it is advisable to keep these fish only singly in the aquarium. Otherwise, you will hardly ever have a specimen with intact fins. A pair is only kept together for breeding. The sexes of adult S. maculatus (from about 15 cm total length) can be distinguished by the shape of the anal fin. This species spawns belly-up among the roots of floating plants near the water’s surface. These piranhas do not care for their fry.

Maximum size: approx. 20 cm; Temperature: 22–28°C; pH and hardness: not important for general care (tap water), but soft and acidic for breeding; Diet: coarse frozen and live food; Social behavior: aggressive solitary fish, best kept alone.

For our customers: these fish are listed under codes 292263 (6–8 cm) through 292266 (12–15 cm) on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

Indonesia is increasingly becoming a center for the breeding of ornamental fish, particularly larger species. In the characin group, various silver dollars and pacus (e.g., Metynnis, Myloplus, and Colossoma), Semaprochilodus,  Chalceus species, and headstanders (Chilodus, Leporinus, Abramites, Anostomus, Synaptolaemus) have been bred here, some of them already for decades. Most of these fish reach sizes between 15 and 30 cm, making them significantly larger than the “classic” ornamental fish size. Some species (e.g., Colossoma) are certainly used for dual purposes. The attractive juveniles are marketed for the aquarium trade, while the larger specimens are sold as food fish.

Thanks to this strategy, Indonesia possesses the highly specialized expertise that makes it possible to breed even those species that are rarely available from the wild and only in very small numbers. Hypomasticus despaxi (which was classified in the genus Leporinus until a few years ago) is one of the smaller species in the genus. Its maximum length is reported to be 16 cm. It occurs exclusively in fast-flowing sections of the upper reaches of rivers in French Guiana (from the Maroni to the Oyapock). These are very difficult-to-access areas. We are now able to offer captive-bred specimens of this attractive species for the first time. In adult specimens, the second light-colored longitudinal band from the top is a vivid pink—very attractive!

Maximum size: approx. 16 cm; Temperature: 22–28°C; pH and hardness: not significant for general care (tap water), but soft and acidic for breeding; Diet: Omnivorous, plant-based food is very important; Social behavior: Interacts intensively with conspecifics; a hierarchy is established, which is accompanied by harmless fin damage (the fins grow back); juveniles exhibit schooling behavior.

For our customers: these animals are listed under code 265737 (3–5 cm) on our stock list. Please note that we supply exclusively to wholesale customers.

Text & Photos: Frank Schäfer

We recently highlighted the Striped Headstander (Anostomus anostomus) and mentioned that this sought-after species—which is rarely available as a wild-caught import—can now also be obtained as captive-bred specimens from Indonesia (https://www.aquariumglaser.de/en/fisharchive/anostomus-anostomus-4/).

Now, for the first time, we have also received large captive-bred specimens (8–12 cm) from Indonesia. These are truly beautiful fish! Unlike the wild-caught specimens we most recently sourced from Guyana, the caudal fins of the captive-bred fish are just as red as the dorsal fins. Unfortunately, we do not know where the original broodstock from the Indonesian breeders originated. Overall, A. anostomus is very widely distributed in the wild; scientific records exist from Brazil, Ecuador, Guyana, Peru, Colombia, and Suriname. Red-tailed Striped Headstanders are known, for example, from Suriname.

Maximum size: approx. 16 cm; Temperature: 22–28°C; pH and hardness: not significant for general care (tap water), but soft and acidic for breeding; Diet: Omnivorous, with plant-based supplements important; Social behavior: Schooling fish with a social hierarchy.

For more information, visit our website: www.aquariumglaser.de

For our customers: These fish are listed under code 205514 on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

For the first time, we were able to import a species of tetra from Peru that was previously completely unknown to us. It was offered as “Moenkhausia naponis.” This species does exist, and our new import bears a certain resemblance to it; in particular, the distinctly pronounced longitudinal stripe that begins below the dorsal fin, combined with the (sometimes—depending on the fish’s mood) double shoulder spot, point in this direction. We have therefore chosen the designation Moenkhausia cf. naponis for our stock list, as there are also differences from the description of M. naponis.

We find the behavior of these fish—which grow to a maximum length of about 5 cm—remarkable. Characins are generally considered peaceful schooling fish. However, our new imports are anything but that. Their behavior is more reminiscent of that of piranhas. When they sense danger, the fish do form a group, but small groups (5 fish) simply do not work. The strongest fish becomes a tyrant overnight, herding all its conspecifics into a corner. These fish should therefore be kept in groups of at least 10 specimens in aquariums that are as large and structurally diverse as possible.

Their behavior and general appearance strongly remind us of the Apricot Tetra (Dectobrycon armeniacus), which also originates from Peru. It is therefore possible that our new import is a Dectobrycon species that has not yet been scientifically described.

Maximum size: approx. 5–6 cm; Temperature: 22–28°C; pH and hardness: not important for care (tap water), but likely soft and acidic for breeding; Diet: Omnivorous; Social behavior: Aggressive schooling fish.

For our customers: These animals are listed under code 268683 on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

For several years now, tetras have been experiencing a renaissance in the aquarium hobby. As a result, exporters are also striving to offer new species that have not previously been available to aquarists. It is sometimes impossible to identify such new arrivals. This may be because they are (in the scientific sense) old but “forgotten” species, or because there are far more species yet to be scientifically documented than many people realize.

In any case, we were recently able to import a “tetra Cenepa”—that is, a tetra originating from the drainage of the Rio Cenepa (a river in northern Peru that forms part of the border between Ecuador and Peru and flows into the Marañón, which is the upper reaches of the Amazon)—that is not identical to any species known to us. It has (as far as can be judged from photos) a short, incomplete lateral line and a heavily scaled caudal fin, thus fitting the definition of the genus Hemigrammus.

Very similar are the “Hasemania sp. Yurimaguas,” also native to Peru (see https://www.aquariumglaser.de/en/fisharchive/hasemania-sp-yurimaguas-sp-orange-2/) and the Brazilian species Hyphessobrycon moniliger (https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/hyphessobrycon-moniliger-4/). Hemigrammus sp. Cenepa is an extremely rare species and will likely remain so. Tetra enthusiasts should therefore seize the opportunity if they come across this species for sale.

Maximum size: approx. 4 cm; Temperature: 22–28°C; pH and hardness: not important for care (tap water), but soft and acidic for breeding; Diet: omnivorous; Social behavior: peaceful schooling fish.

For our customers: These animals are listed under code 256012 on our stock list. Please note that we supply exclusively to wholesale customers.

Text & photos: Frank Schäfer

We have received some magnificent tetras from Colombia that, in neutral mood and as young fish, bear a strong resemblance to the Neon Costello, Hemigrammus hyanuary. However, they can be reliably distinguished from that species by their red iris; in H. hyanuary, the iris (that is, the rim of the eye surrounding the pupil) is always brass-colored, never red. Once acclimated and adult, specimens of Hemigrammus sp. aff. hyanuary resemble Black Neons (Hyphessobrycon herbertaxelrodi) or Meta tetras (Hyphessobrycon metae).

Maximum size: ca. 4 cm; Temperature: 22–28°C; pH and hardness: not critical for care (tap water), soft and acidic for breeding; Diet: omnivorous; Social behavior: peaceful schooling fish.

For more information, visit our website: www.aquariumglaser.de

For our customers: these fish are listed under code 256513 on our stock list. Please note that we supply exclusively to wholesalers.

Text & photos: Frank Schäfer

The Marbled headstander is perhaps the most unusual of all the headstanders. This beautiful fish grows to about 15–20 cm in length and is virtually unmistakable due to its deep body shape. There is only one other Abramites species, A. eques, but it has never been imported live. It is found exclusively in the Rio Magdalena in Colombia. All known live photos purporting to show A. eques are, in reality, color variants of A. hypselonotus. In A. eques, there is no band on the front of the body; the first band begins below the dorsal fin and runs down the center of the body.

In contrast, in the extremely widespread Abramites hypselonotus—which is found practically throughout South America east of the Andes, from Argentina to Venezuela—the striping begins directly behind the head. Moreover, at least in wild-caught specimens, each individual can be identified by its unique striping pattern. It is doubtful that the Marbled headstanders found throughout this vast region are truly all the same species, but they do look very, very similar. 

We usually stock captive-bred specimens of this fish from Indonesia, but we occasionally receive wild-caught specimens as well. The fish currently swimming in our tanks come from Peru; the ones pictured are wild-caught specimens from Peru and are in the medium size range of 5–6 cm.

Abramites are social fish that interact constantly. If you have too few of them, this can become a nuisance; in larger groups and large aquariums, however, it’s not as much of an issue. Unfortunately, these beautiful fish are extreme herbivores.

For our customers: Depending on their size, these fish are listed on our stock list under codes 200501 (3–4 cm) through 200505 (9–12 cm). Please note that we supply exclusively to wholesale customers.

Text & Photos: Frank Schäfer

The genus Melanocharacidium (the name roughly means “black Characidium”) was established in 1993. The author assigned eight species to the new genus, six of which he described as new. Since then, only one additional species has been added: M. auroradiatum from the Rio Araguaia in Brazil. We were recently able to import a Melanocharacidium species from Peru for the first time in quite a while. Three of the nine species are reported from this country: M. dispilomma, M. pectorale, and M. rex. Of these three species, our new imports match the description of M. dispilomma very closely.

Melanocharacidium dispilomma has a very wide distribution in South America. Records exist from Bolivia, Brazil, French Guiana, Guyana, Colombia, Peru, Suriname, and Venezuela—in other words, practically all major river systems in the northern part of the subcontinent. In such cases, it stands to reason that we are likely dealing with a complex of very similar species rather than a single species. But who knows? We had previously imported a very similar species from Brazil, which we designated as “cf. dispilomma” (see: https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/melanocharacidium-cf-dispilomma-2/). However, those specimens were noticeably slimmer in build. We were unable to identify another species from Peru at all: https://www.aquariumglaser.de/en/09-characoids-tetra-relationship/melanocharacidium-sp-peru-2/ : So there’s still plenty of room here for aquarists with a thirst for research.

But M. dispilomma are a real asset for everyone else, too. The comical behavior of these fish is just plain fun! Based on our observations, these Melanocharacidium appreciate some cover from above. At least in the photo tank, they clearly preferred perching spots where either a root arched over them like a cave or a plant provided cover. Among themselves, they are constantly busy teasing one another. However, we have not yet observed any damage to their fins or persistent bullying. These bottom-dwelling characins behave completely neutrally toward fish of other species. They will eat any ornamental fish food of a suitable size that is offered to them. This species reaches a total length of about five centimeters.

For our customers: these fish are listed under code 267662 on our inventory list. Please note that we supply exclusively to wholesale customers.

Text & photos: 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