11. Gymnotiformes: Knifefishes of the New World (23)

Apteronotus leptorhynchus (A. macrostomus)

15. September 2023

The “Brown Ghost” is one of the most popular knifefishes in the aquarium. The species is not small, but not huge either: the maximum length to be expected is about 20 cm. This makes it less than half the size of its black cousin (A. albifrons). It is fascinating to observe knifefish in the aquarium. At first they are still shy and hide, but soon the comparatively intelligent fish understand that there is no danger to them in the aquarium. Then they delight the aquarist with their swimming skills, for knifefish can swim forward and backward with equal speed and elegance. All knifefish belong to the electric fish, but they cannot deliver an electric shock, the voltage is much too low for that. The electrical discharges are used by the fish for orientation (like the echolocation of bats on land) and for intra-species communication. In order to avoid electrosmog in the aquarium, each animal needs hiding places in the form of a cave, which shields the electrical signal. Not beautiful, but extremely practical for this purpose are PVC tubes of various diameters.

For decades, the Brown Ghost was believed to have a vast range in South America. In 2013, scientists Carlos David de Santana and Richard P. Vari published a study in which they showed that there is not one widespread species, but that at least nine different species can be identified, each with a relatively small range. Purely externally, however, they cannot be distinguished on live animals. The fish offered in the hobby originate from Colombia and belong with highest probability to Apteronotus macrostomus. This species comes from the surroundings of the city Villavicencio at the Rio Meta, where numerous ornamental fish catchers are active. The “true” A. leptorhynchus is probably not imported; it comes from the Essequibo River drainage in Guyana. However, since there are no significant external differences between the Brown Ghost species, they will probably continue to be referred to as “Apteronotus leptorhynchus” in the trade.

For our customers: the animals have code 208002 on our stocklist. Please note that we only supply to wholesalers.

Text & photos: Frank Schäfer

Brachyhypopomus brevirostris

19. December 2022

Knifefishes are found in Africa, Asia, and South America, with Old World and New World species not closely related. As aquarium fishes, knifefishes are particularly attractive because their elegant swimming style, created by the long anal fin extending over the belly and tail, is fascinating to watch. Like ghosts, the animals glide forward as well as backward through the water.

We currently have a very rare imported knifefish in the stock. Brachyhypopomus brevirostris is a species that grows to about 20-40 cm in length but only as thick as a thumb. It is a representative of the family Hypopomidae. B. brevirostris is widespread in South America, our animals come from Peru. Males and females clearly differ in head shape, males also grow larger and in uninjured specimens they also have a small caudal fin, which females lack. However, in their native habitat, many fish apparently specialize in biting off part of the tail of knifefish. Therefore, South American knifefishes are the only fishes that can regenerate the tail including the spine.

Among themselves Brachyhypopomus are pleasantly peaceful. They are small carnivores, easy to feed with frozen and live food. Like all South American knifefish, they possess a weakly electrical organ that they use much like bats use their ultrasound. This allows South American knifefish to move in complete darkness without ever bumping into anything.

For our customers: the animals have code 210803 on our stock list. Please note that we only supply wholesale.

Text & Photos: Frank Schäfer

Steatogenys duidae

28. January 2022

From Peru we have received exceptionally nice knifefishes of the species Steatogenys duidae. According to current knowledge the genus Steatogenys comprises three species, all of which have zebra-like stripes. With a final length of about 20 cm they remain comparatively small, only S. ocellatus grows significantly larger at 30 cm. The three species are very similar in color. The best way to distinguish them is by the anal fin coloration. S. elegans has a mostly colorless anal fin, this fin is strongly marbled/striped in S. duidae and dark with light spots along the ventral side in S. ocellatus. 

Steatogenys are considered comparatively peaceful towards each other and towards other species of fish. Mainly small invertebrates, like mosquito larvae, crustaceans or worms are eaten. 

Around the mouth the animals have extremely distinctive sensory pits. With this they can still perceive the electrical activity of the muscles of a wriggling worm. The eyes are overgrown with a fine skin and are not very functional. This clearly shows that these knifefishes, which are found in nature in the terra firme forests of the entire Amazon and Orinoco basins in smaller flowing waters, do not search for and find their food visually, but sensory.

For our customers: the animals have code 293824 on our stock list. Please note that we only supply wholesale.

Text & photos: Frank Schäfer

Rhamphichthys rostratus

28. December 2020

Since some time we can offer a very interesting knife-fish species of the genus Rhamphichthys, which we receive as offspring from Indonesia. Rhamphichthys are attractive fish, but they require strong nerves from their keeper, because they rest lying on their side and look like dead at first sight. But they are very happy, only sleeping. Apparently they can rely so much on their camouflage coloration that they can really lie around everywhere. Since they are twilight and nocturnal animals that rest during the day, this can be quite disturbing for the worried keeper!

In contrast to many other weakly electric fish species – to which Rhamphichthys belongs – which are usually quite quarrelsome with each other, Rhamphichthys like to cuddle and are looking for the physical closeness of conspecifics.

There are 8 currently recognized Rhamphichthys species, which look extraordinarily similar. Since we do not know the original origin of the bred animals, we keep the name Rhamphichthys rostratus for the time being. This species has a wide distribution in South America: Argentina, Bolivia, Brazil, the Guyana countries, Colombia and Uruguay. It grows to a maximum length of 100 cm, although such dimensions are probably very rare. Realistically, one must presumably proceed from approximately 50 cm in the aquarium, however, they need a very big aquarium in any case on a long-term basis. At present our animals are 15-20 cm long.

As the wide distribution already suggests, hardness and pH-value do not play a significant role for this species, the water temperature can be in the range of 22-28°C. Soft sandy ground, in which the animals can dig in, is highly recommended. In our facility they eat living Tubifex and frosted mosquito larvae. With their small, tubular mouth they are hardly dangerous for other fish.

For our customers: the animals have code 287403 on our stocklist. Please note that we only supply the wholesale trade.

Text & photos: Frank Schäfer

Gymnotus carapo

19. June 2020

The number of scientifically described species in the genus Gymnotus increases rapidly recently. Since the last complete revision of the New World Knifefishes by Francisco Mago-Leccia in 1994 34 new species and 7 subspecies have been described, raising the total number of known species to 43. Members of the genus Gymnotus are cylindrical shaped and most often they have a quite attractive pattern. The maximum size that can be reached depends on the particular species. The smallest ones are said to reach only 10 cm, the largest up to 40 cm.

The Banded Knifefish (Gymnotus carapo) is the first species that became known to science and been described already back in 1758. The species has an enormous distribution in South America; however, one should keep in mind that many mis-identification probaly have appeared in elder literature. Gymnotus carapo belongs to the larger species of the genus. In 2017, 7 new subspecies of G. carapo have been described. The specimens from Venezuela, which we have currently in stock, belong to the subspecies Gymnotus carapo septentrionalis. In some specimens the banded pattern becomes a spotted pattern when they grow larger than about 20 cm. Smaller specimens are all banded. Maybe the pattern shows the sex in larger specimens?

Principically speaking Gymnotus carapo would make excellent aquarium fishes – despite the size they can grow. They species inhabits often swamp areas, has an accessory breathing organ and is very undemanding, has a very attractive pattern and swims – like all knifefishes – in a fascinating way. But sadly all Gymnotus are extremely aggressive against conspecifics. This makes it most often impossible even to keep a pair together. External differences between the sexes are unknown for Gymnotus. That is really a pity, because breeding Gymnotus would make a great project. Gymnotus are paternal broodcarer. From the wild, nest-building males have been described, in captivity they proofed to be mouthbrooders. Most probably sibling, but different speces were involved in the two studies.

Currently we have very nice specimens from Venezuela in stock. The fish are between 12 and 15 cm long and all banded, with one exception, a large spotted specimen, 25-30 cm long. Doesn´t that make a good opportunity to try the species?

For our customers: the fish have code 255204 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Steatogenys elegans

20. January 2020

From Peru we have received extremely pretty knife fish of the species Steatogenys elegans. The genus Steatogenys comprises three species, which are all zebra-like striped. With a  total length of approximately 20 cm, they remain comparatively small, only S. ocellatus clearly becomes bigger with 30 cm. The three species are very similar in color. One can distinguish them best on the basis of the anal-fin-coloring. S. elegans has a largely colourless anal fin, this fin is strongly marbled in S. duidae and dark in S. ocellatus with light spots along the belly. 

Steatogenys are considered comparatively peaceful among each other and against other fish. They mainly feed on small invertebrates such as mosquito larvae, crustaceans or worms. 

Around the mouth the animals show extremely pronounced sensory pits. With this, they can still perceive the electrical activity of the muscle activity of a wriggling worm. The eyes are overgrown with a fine skin and not very functional. This clearly shows that these knife fish, which are found in nature in the Terra firme forests of the entire Amazonas and Orinoco river basin, do not seek and find their food optically but sensory.

For our customers: the animals have code 293804 on our stocklist. Please note that we only supply wholesalers.

Text & photos: Frank Schäfer

Gymnotus chaviro

22. June 2018

More and more species of Gymnotus become known to science. Gymnotus chaviro originates from Peru. Here it inhabits the basin of the upper Rio Jurua. The species is found together with its close relative G. carapo. The pattern of G. chaviro is species-specific. However, there is one usefull feature mentioned in the original description: the anal fin in G. chaviro is grey and black in G. carapo. This enables hobbyists to distinguish the two species, as it is very likely that they are at least occasionally collected and imported together.

The largest specimen of G. chaviro known so far was 27.5 cm long. In the original description (Maxime & Albert, 2009) a very interesting note can be found: sometimes G. chaviro can be seen in groups in the natural habitat! This could mean that this knife fish is rather peaceful against conspecifics and that there is a chance to keep several specimens together. All other species of Gymnotus imported so far proofed to be quite aggressive and could be kept singulary only. However, there are still no published observations on the aquarium biology of G. chaviro.

For our customers: the fish have code 255184 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Sternarchogiton preto

29. January 2018

Most probably this importation of this black knifefish from Peru („preto“ means „black“) is the first one to Europe. At least the pictures of a life specimen we post here are the only ones we know about. The uniform black coloration is a good feature to distinguish the species from other members of the genus (there are five species of Sternarchogiton known so far). However, if one takes a closer look on the pictures a light stripe over the back is visible in many of them. This is not a true coloration, but a effect from the light. The mucus of the fish is obviously very thick over the back, which s the reason for that light stripe.

Aquarium observations show clearly that this knifefish tends to swim near the water surface. They often take air and water in the mouth; the water becomes spit out in form of a small blast. Most probably these fish feed in the wild on land insects that fall in the water. The species grows to a length of 20-25 cm, so our two specimens are fully grown already. Like most knifeffish these animals are very intelligent and observing them is extremely interesting.

For our customers: the fish have code 293905 on our stocklist. Please note that we exclusively supply the wholesale trade. Only two specimens available!

Text & photos: Frank Schäfer

Apteronotus albifrons WHITE

17. July 2017

The Black Ghost (Apteronotus albifrons) is a most beautiful and elegant knifefish from South America. The species has a very wide distribution, wild collected specimens most often come from the Orinoco (Colombia and Venezuela). However, the up to 50 cm long species is also bred since many years in Indonesia on a regular basis.

The mode of swimming this species performes is uncomparable. There is no thinkable manouvre that cannot be figured by the species, may it be straight on, backwards, head up or head down, upside down or upside up.

First we obtained in 2008 a white sport of the Black Ghost from Indonesia. Now we were able once more to get these interesting animals, this time they are bred in Europe. They don´t differ at all from the wild type fish in respect of elegance and swaggering (these fish fight for their position in the hierarchy with mouths wide open; in this position they try to push away the contrahent), but they appear even more than their black ancestors in a ghosty way…

For our customers: the fish have code 207551 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

How to pack 600 Volts!

13. February 2017

The Electric Eel, Electrophorus electricus, has the strongest electric discharges of all known electric species of fish (electric catfish, electric rays, elephant fishes, knifefishes). Up to 600 Volts are quite common, very large specimens may produce even stronger discharges. The Electric Eel is no eel at all, but belongs to the New World Knifefishes. Five families, 30 genera, and about 180 species are known, all of them are electric. But only the Electric Eel uses its power to konck out prey or to defend itself against enemies. All other species use their (weak) electric organ only for infraspecific communication or for orientation. This organ works a bit like a radar.

The Electric Eel becomes more than 2 metres long. Large specimens are much wanted by public aquaria all over the world. Keeping these large fish is astonshing simple. As the Electic Eel often inhabits swampy habitats it has developed a breathing organ that enables the fish to breath atmospheric air they take from the water surface.

Click here for the video: zitteraalfang – Klein

You can see on the video enclosed how such a muscleman is caught and prepared for transportation to the final homeplace – in this special case a public aquarium in France. The most important thing in such an operation is to keep calm. Neither the animal nor the catcher must become nervous, otherwise accidents may appear.

For our customers: the Electric Eel has code 25320 on our stocklist. Please note that we exclusively supply the wholesale trade. Available in limited numbers only!

Text & photos: Frank Schäfer, video & catcher: Christian „The Mighty“ Fiedler

Apteronotus albifrons WHITE

12. July 2016

207551-apteronotus-albifrons-white1

The Black Ghost (Apteronotus albifrons) is a most beautiful and elegant knifefish from South America. The species has a very wide distribution, wild collected specimens most often come from the Orinoco (Colombia and Venezuela). However, the up to 50 cm long species is also bred since many years in Indonesia on a regular basis.

207551-apteronotus-albifrons-white2

The mode of swimming this species performes is uncomparable. There is no thinkable manouvre that cannot be figured by the species, may it be straight on, backwards, head up or head down, upside down or upside up.

207551-apteronotus-albifrons-white3

First we obtained in 2008 a white sport of the Black Ghost from Indonesia. Now we were able once more to import these interesting animals. They don´t differ at all from the wild type fish in respect of elegance and swaggering (these fish fight for their position in the hierarchy with mouths wide open; in this position they try to push away the contrahent), but they appear even more than their black ancestors in a ghosty way…

207551-apteronotus-albifrons-white4

For our customers: the fish have code 207551 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & Photos: Frank Schäfer

Rhamphichthys hahni

26. May 2015

Rhamphichthys hahni Rhamphichthys hahni Rhamphichthys hahni

Yesterday we received for the first time ever an extremely unusual species of knifefish from Paraguay: Rhamphichthys hahni. We obtained three specimens of about 20-30 cm length. Despite the fact that the species has been described in the year 1937 already it has been overlooked by most of the following scientists. The photos posted here are only snapshots of our freshly imported specimens, but due the rarity of these fish we want to present them to you immediately.

Text & photos: Frank Schäfer

Orthosternarchus tamandua

14. November 2014

There
are several critters among the South American knifefishes, but
Orthosternarchus tamandua is most probably the most unusual of all. We
were able to import a specimen from Peru. Our fish has a length of 25-30
cm, the maximum length reported for the species is about 45 cm.

For
our customers: the fish has code 271327 on our stocklist. Please note
that we exclusively supply the wholesale trade. Only one specimen
available!

Text & photos: Frank Schäfer

Sternrachorhynchus from Peru

28. July 2014

Sternarchorhynchus aus Peru Sternarchorhynchus aus Peru Sternarchorhynchus aus Peru Sternarchorhynchus aus Peru

This week we introduced to you already a species of knifefish from Peru: Brachyhypopomus brevirostris (see http://www.aquariumglaser.de/en/news.php#1122). The odd Sternarchorhynchus, which is theme of this newsletter, originates also from Peru, but belongs to a different family, eg the Apteronotidae.

The number of described species of Sternarchorhynchus has risen enormously in the past few years. Up to 1994 only 4 species where known, in 2006 the number of known species increased to 10 and now (2014) 32 species are accepted! This makes the genus Sternarchorhynchus the most species-rich genus of the Apteronotidae. The main differences between the species can be found in the shape of the snout. When the fish occurred here only a quite rough determination was possible. This is why they are listed under the name of S. mormyrus on our stocklist. The analysis of the photos, however, makes it much more likely that our fish belong to the species S. goeldii, which has been described only in 2010. S. mormyrus becomes about 50 cm long, S. goeldii about 30 cm. Currently our fish are 14-16 cm long.

However, more interesting than the question how the fish should be named is their behaviour. The animals are a bit quarrelsome against each other. But they do not hurt their counterpart, they swim with high speed and breathtaking elegance around each other. The better swimmer wins the combat. Also a very special role of the snout can be observed while he fish are fighting: they use it like the sword of a foil fencer. The pictures published here are the first existing ones to document this fascinating behaviour.

Feeding Sternarchorhynchus in aquaria is no problem, the fish take readily any type of live and frozen food.

For our customers: the fish have code 293974 on our stocklist. Please note that we exclusively supply the wholesale trade. Available in very limited numbers only!

Lexicon: Sternarchorhynchus means “snout with the anus at the breast”; this refers, of course, to the long snout and to the fact that in Sternarchorhynchus the anus is placed immediately behind the head. mormyrus: means “mormyrid”; the members of the African fish genus Mormyrus have a comparably long snout. goeldii: dedication name for Emilio (actually Emil) Goeldi (1859-1917) as a appreciation for his merits regarding the knowledge of the animals of Amazonia.
Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Peru
Verfügbare Größe in cm 14-16

Adontosternarchus clarkae

19. November 2012

Marbled Dwarf Ghosts.

The most important species New World Knifefishes or Ghosts in the ornamental fish trade are without any doubt the Black Ghost (Apteronotus albifrons) and the Brown Ghost (A. leptorhynchus). We have both species in stock on a regular basis, the Black Ghost both as wild collected from Colombia/Venezuela and bred ones, the Brown Ghost wild collected from Colombia/Venezuela.

Now we have a third species from Venezuela in stock, which is currently only rarely available, but which has the potential to compete with the two species mentioned already: the Marbled Dwarf Ghost, Adontosternarchus clarkae. This pretty species is as fascinating as the Apteronotus species, eg the special way of swimming in all directions that reminds the observer in watching a underwater ballet, but has the advantage that is grows only to a maximum length of about 20 cm; the most specimens stay much smaller. In contrast to that, A. albifrons, attains a length of 50 cm and A. leptorhynchus of 30 cm.

Against tankmates, may they belong to the same or to different species, A. clarkae are completely peaceful.They need hiding places and a well structured aquarium. Blodworm is the food they like most, but the fish also take readily any other type of live, frozen or granulated fishfood. One should take care that the ghosts get enough food, for especially during acclimatisation the fish are preferably crepuscular.

The fish are totally undemanding regarding water chemistry. The water temperature should be between 24 and 28°C.

For our customers: the fish have code 202782 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Apteronotus: ancient Greek, means “without fin on the back”. albifrons: Latin, means “with a white forehead”. leptorhynchus: ancient Greek, means “with a small snout”. Adontosternarchus: Latin, means “toothless Sternarchus”; Sternarchus is another genus of New World Knifefish. clarkae: dedication name for Kate Clark, the collector of the species.

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Venezuela
Verfügbare Größe in cm 7-10

Adontosternarchus nebulosus

23. August 2012

For the first time ever we can offer this very nice and comparatively small species (around 20 cm) of knifefish. The species has been described scientifically only in 2007; our specimens originate from Peru. Available in limited numbers only!

For our customers: the fish have code 202794 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Compsaraia samueli

7. February 2012

Compsaraia samueli Compsaraia samueli Compsaraia samueli

Only a few specimens of one of the most remarkable knifefishes of the New World reached us from Peru: Compsaraia samueli. The males of this “pelicano knifefish” develope grotesque long snouts. The males are absolutely intolerant against each other. They fight with mouths wide open in a manner that is known from fighting male deer.

The maximum size of the species, which has been described scientifically only in 2009, is about 23 cm. Males become sexually ripe with about 19, females with 15 cm length. In our fishhouse, the fish are fed with Tubifex and small feeder fish (Tanichthys). Regarding the water the knifefish, which are collected in the vicinity of Iquitos, are quite undemanding. However, it is best to keep the fish in soft and slightly acidic water and temperatures between 22 and 26°C.

For our customers: the fish have code 218205 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Compsaraia: from ancient Greek, means “with elegant fin ray”; the genus name refers to the anal fin structure. samueli: dedication name for Samuel Albert.

Suggestion of a common name: Pelicano Knifefish, Samuel´s Ghost Knifefish

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Peru
Verfügbare Größe in cm 15 - 18

Eigenmannia trilineata

29. August 2011

We received wonderful specimens of Eigenmannia from Guyana. They show three black longitudinal stripes on a smokey ground. This fits perfectly to the pattern described in the species E. trilineata, which is known so far only from the Paraguay-Paraná system (Argentina, Brazil, Paraguay, Uruguay).

May that be as it is: Eigenmannia are fantastic aquarium fish that show an incomparable elegance. Males can reach about 40 cm in length, which is double as long as females can become. Females have also a much shorter snout. Breeding of Eigenmannia is possible if a rainy season is imitated. As soon as the fish are in the right condition, they spawn in the roots of swimming plants.

Knife fishes need well structured tanks with a good number of hiding places. Feeding them is pretty easy, for the fish accept readily any type of live and frozen food. Many specimens also accept granulates.

For our customers: the fish have code 252905 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Eigenmannia: dedication name for Carl H. Eigenmann (1863-1927). trilineata: Latin, means “with three stripes”.

Suggestion of a common name: Smokey Glass Knifefish

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Guyana
Verfügbare Größe in cm 15-20

Adontosternarchus clarkae

23. August 2011

This small (maximum length up to 20 cm) knifefish from Venezuela is only rarely imported and again we were able to obtain only a few specimens. It is a very nice and peaceful species. The genus Adontosternarchus currently comprises four accepted species which can be distinguished best by differences in the head profile in combination with the shape of the mouth.

Like all South American knifefishes, this species is weakly electrical and communicates with conspecifics via electrical impulses. Of course, these impulses are also used for orientation. Knifefishes develop most activity at dawn and so the tank should not be too much illuminated and should contain a good number of hiding places.

The fish feed basically on Tubifex and frozen fishfood. Regarding the water chemistry they seem to be undemanding. However, soft and acid water should be preferred against hard and alcaline water. The water temperature should be a little higher than usual, about 26-28°C will do best.

For our customers: the fish have code 202782 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Adontosternarchus: ancient Greek, means “Sternarchus without teeth”; Sternarchus is another genus of knifefish. clarkae: dedication name for Ms. Kate Clark, who was the first collector of the species.

Suggestion of a common name: Marbled Knifefish

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Venezuela
Verfügbare Größe in cm 8 -10

Apteronotus leptorhynchus GOLD

11. January 2011

A very special knifefish reached us currently from Colombia: a golden Apteronotus leptorhynchus! The species is widespread and common in Colombia and we have the “Brown Ghost” regularly stocked; but this is the first time ever that we became aware of a specimen with such an unique coloration.

For our customers: the animal has code 208013 on our stocklist.Plaese note that we exclusively supply the wholesale trade.

Lexicon: Apteronotus: ancient Greek, means “with no fin on the back”. leptorhynchus: ancient Greek, means “with a small snout”.

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Kolumbien / Colombia
Verfügbare Größe in cm 8-10

Parapteronotus bonapartii

30. September 2010

There is a lot of movement in the South American Knifefishes. Science has put an eye on these fascinating, electrical fishes and so a flood of new species descriptions and revisions has been published quite recently. Most genera and species are only weakly electric and use the electric pulses for orientation and communication. However, the Electric eel (Electrophorus electricus), which belongs also to the South American Knifefishes, can produce electric shocks that can be even fatal to human beings (500 volts at 1 ampere).

Parapteronotus bonapartii can reach a total length of up to 40-50 cm. The history of its scientific names is long and complicated. It was back in 1942 that Eigenmann and Allen described a grotesque knifefish with an enormous snout under the name of Apteronotus anas. It took until 2002 to find that A. anas represents only the fertile male of the already known species Apteronotus hasemani which was described in 1913. It could be shown that the snout of the male grows constantly when the individual reaches sexual maturity. Consequently the name Apteronotus anas became a synonym (= invalid name) of the elder A. hasemani. Even one year before this discovery was published by Fernades et al. Albert (2001) described a new genus, Parapteronotus for A. hasemani. Sadly this was not mentioned in Fernades et al., probably due to overlapping of the submissions of both papers. Finally, in 2007 Triques showed that A. hasemani is identical with the species described in 1855 by Castelnau under the name of Sternarchus bonapartii. So the currently valid name of the fish is Parapteronotus bonapartii.

We were able to import a pair of these fantastic fishes from Peru now for the first time. The specimens are 30 – 35 cm long already. As Apteronotus-species are known to be sometimes quite nasty against each other we keep the two fish separated. The animals have very obvious teeth. The sense of them is unknown so far. Our knifefish do not feed on small fish. Mainly they get live Tubifex which are taken readily.

Nothing is known about the breeding behaviour of Parapteronotus bonapartii. However, the close relative Apteronotus leptorhynchus has been bred in aquaria already (Kirschbaum & Schugardt, 2002). The latter species does not take broodcare in any way.

For our customers: the fish have code 277607 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Apteronotus: ancient Greek, means “with no fin on the back”. Parapteronotus: ancient Greek, means “close to Apteronotus”; this is meant in the sense of sister-groups. Apteronotus is another genus of knifefish. leptorhynchus: ancient Greek, means “with a small snout”. hasemani: dedication name for J. D. Haseman. Sternarchus: ancient Greek, means “breastbone-anus”. bonapartii: dedication name for prince Charles Bonaparte, “a prince of science”. Electrophorus: named after an early physical instrument which transformed mechanical work in electrostatic charge. electricus: Latin, means “electrical”. anas: Latin, means “duck”.

Suggestion of a common name: duckbill-knifefish

Text & photos: Frank Schäfer

Literature:

Albert, J. S. (2001): Species diversity and phylognetic systematics of American knifefishes (Gymnotiformes, Teleostei). Miscellaneous Publications, Museum of Zoology, University of Michigan No. 190: i-vi + 1-127.

Castelnau, F. L (1855): Poissons. In: Animaux nouveaux or rares recueillis pendant l’expédition dans les parties centrales de l’Amérique du Sud, de Rio de Janeiro a Lima, et de Lima au Para; exécutée par ordre du gouvernement Français pendant les années 1843 a 1847 … Part 7, Zoology. Animaux nouveaux or rares recueillis pendant l’expédition dans les parties centrales de l’Amérique du Sud, de Rio de Janeiro a Lima, … v. 2: i-xii + 1-112, Pls. 1-50.

Cox Fernandes, C. C. , J. G. Lundberg, & C. Riginos (2002): Largest of all electric-fish snouts: Hypermorphic facial growth in male Apteronotus hasemani and the identity of Apteronotus anas (Gymnotiformes: Apteronotidae). Copeia 2002 (no. 1): 52-61.

Kirschbaum, F. & C. Schugardt (2002): Reproductive strategies and developmental aspects of mormyrid and gymnotiform fishes. Journal of Physiology-Paris 96: 557–566.

Triques, M. L. (2007): Parapteronotus bonapartii (Castelnau), considerado sinônimo sênior de Parapteronotus hasemani (Ellis) (Teleostei, Apteronotidae). Revista Brasileira de Zoologia v. 24 (no. 1): 84-86.

Angaben zum Tier
Herkunft Peru
Verfügbare Größe in cm 30 - 35

Newly in: Electric eels

29. September 2010

Wonderful Electric eels (Electrophorus electricus) from Peru reached us lately. The animals are 40-50 cm long. The three of them are astonishingly peaceful among each other and feed  readily. The fish have nice pale spots on the flanks, which are typical for specimens from Peru  and which make the fish even more attractive.

For our customers: the fish have code 253206 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon:
Electrophorus: named after an early physical instrument
which transformed mechanical work in electrostatic charge. electricus:
Latin,means “electrical”.

Text & photos: Frank Schäfer

Gymnorhamphichthys cf. hypostomus

21. October 2009

The sand knifefishes (Rhamphichthyidae) from South America belong to the weak electric fishes. They send continously electric impulses which are used for tracing prey, orientation, and intraspecific communication. Currently three genera and 14 species are known.

The genus Gymnorhamphichthys, also called thermometer knifefishes, contents five described species. There is hardly anything known about the fish, because they are strictly night active and stay during daytime burried in the sand. Thus comprehensive studies in the field are impossible to do.

Our Gymnorhamphichthys have been imported from Peru. So far, no species of Gymnorhamphichthys is reported in the Checklist of the freshwater fishes of South America for Peru. The pattern of our specimens fits best to the pattern described for G. hypostomus. This species, however, has a shorter snout. So it is also possible that our fish represent a species new to science and so we were cautious and stocked them under the name G. cf. hypostomus.

The fish are very peaceful against each other. However, they have no teeth at all nor any other item that would enable them to hurt each other. They are easy to feed, for they readily accept frozen bloodworm which form also a larger part of their natural diet, as was shown in the field for Gymnorhamphichthys when the gut was dissected. Maximum size reported for G. hypostomus is about 20 cm, our specimens are 14-18 cm long.

For our customers: the fish have code 254984 on our stocklist. Please note that we exclusively supply the wholesale market.

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Peru
Verfügbare Größe in cm 14-18