19. Halfbeaks (18)

Hemirhamphodon tengah

27. March 2020

This pretty little fish is a challenge for experienced hobbyists. The species originates from Borneo. In contrast to the widespread prejudice halfbeaks of the genus Hemirhamphodon do not appear in brackish water; they are strictly bound to very soft and acidic water! These fishes are commonly found along with chocolate gouramis and small rasboras.

The other species of Hemirhamphodon are livebearers. Not so H. tengah: this is an egg-laying species. Breeding H. tengah is in most respects similar to breeding killifishes of the Apyhosemion-type. The females like to spawn in java moss, peat or in artificial breeding mops made of wool.

The fish are strictly surface-dwellers. They are not very demanding regarding food, but never take food from the bottom. So they should be fed with flakes and different types of live food. Small fruit flies (Drosophila) are a delicacy for Hemirhamphodon. Maximum length of the fish is about 6 cm.

For our customers: the fish have code 421552 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexikon. Hemirhamphodon: from ancient Greek, means about “with teeth on the halfbeak”. tengah: after the province Kalimantan tengah on Borneo, where the species has been collected initially.

Text & photos: Frank Schäfer

In order to inform you continuously about beautiful and interesting aquarium inhabitants, we have prepared some posts for later publication. This is one of them. Unfortunately the shown animals are already sold out, sorry.

Dermogenys siamensis (D. pusilla)

11. March 2019

The systematics of the widespread, small halfbeaks from South and Southeast Asia are complicated. A first revision of the genus by Mohr in 1936 summarized many previously described species under the synonymy of D. pusilla. This was followed by Brembach in 1991; the name D. pusilla was then used in the broadest sense. It was not until 2001 that Downing-Meisner revised the genus again and split it into several species. Four of them form the Dermogenys pusilla complex. They can certainly only be distinguished by microscopic examinations of the male’s mating organ, the so-called andropodium, but the species are geographically excluded, so that with knowledge of their origin it is also possible to determine them.

We have now received beautiful Dermogenys pusilla in the broadest, oldest sense. They come from the south of Thailand, from the province Petchaburi, district Ban Laem, thus belong to the species Dermogenys siamensis.

For our customers: the animals have code 414202 on our stocklist. Please note that we only supply wholesalers.

Text & photos: Frank Schäfer

Potamorrhaphis labiatus

31. August 2018

The slender freshwater needlefish from South America are much sought for by specialists. Many years only one species was mentioned in the aquarium literature, namely Potamorrhaphis guianensis. This species really exists and is said to be fairly wide spread in South America. But it seems that the needlefish we obtain from Peru currently belong to another species.

There are four accepted species within Potamorrhaphis and after studying the scientific lterature it seems most likely that the Peruvian fish belong to the species P. labiatus. The differences between P. guianensis and P. labiatus mentioned in the scientific literature are not visible in live specimens; anyway, differences in coloration are much more important for us. The most distinctive feature in our Peruvian imports is that there are vertical stripes extending from the lateral stripe in direction of the back. In P. guianensis – judging from photos of live fish collected in Guyana – the lateral stripe is solid and has no extensions.

Potamorrhaphis labiatus attains a maximum length of about 18 cm. Against conspecifics the fish are absolutely peaceful. During the phase of settlement one must take extra care that the fish don´t panic, for otherwise they could heavily hurt the sensitive beak. However, minor wounds of that type are unavoidable and will heal without any complications.

Initially these predators have to be fed with live feeder fish, but well settled specimens accept after some time deep frozen fish from a forceps, too.

For our customers: the fish have code 281544 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Nomorhamphus liemi 

3. November 2017

This wonderfully coloured halfbeak originates from the island of Sulawesi ( = Celebes) where it occurs in the southern half; it is endemic in the Maros highlands. In contrast to the closely related genus Dermogenys the upper and the lower jaw are approximately equally long (thus the generic name). In some species, however, is seems not so clear whether they belong to Dermogenys or to Nomorhamphus.

There are two described subspecies of Nomorhamus liemi, eg N. liemi liemi with black fins and N. l. snijdersi with red fins. In wild collected specimens all intermediate states can be found, so currently no subspecies of N. liemi are accepted scientifically. However, in the hobby specimens with a very high amount of red coloration are still called „snijdersi“.

An interesting feature in N. liemi is the fleshy hook many specimens develope on the lower jaw. It is not known what it is good for.

In the wild, N. liemi mainly inhabits brooks and the fish like a comparatively strong current in the aquarium. They are livebearing fishes, the females can give birth every 4 to 6 weeks. The young are very big, sometimes even 2.5 cm long! The mothers hunt their babies quite fiercely. Breeding will be only successful if the adults are properly fed; live insects (crickets, flies, buffalo-worms etc.) are an important part of the diet.

The water temperatures should be relative low (20 – 24°C), the pH higher than 7. Males are very aggressive against each other. Other tankmates are usually ignored.

For our customers: the fish have code 438833 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Nomorhamphus: from ancient Greek, means “with regular jaws”; this refers to the almost equally long upper and lower jaw, which is the difference to all other halfbeaks. liemi: dedication name. snijdersi: dedication name.

Text & photos: Frank Schäfer

Zenarchopterus dunckeri

21. March 2016

There are 20 valid species in the genus Zenarchopterus, all of them occuring along the Pacific coast of tropical Asia. The maximum length of Zenarchopterus is around 15 cm, only a few species are recorded to reach a greater length, most of them stay smaller. The species are very similar to each other and the only safe way for a positive identification of the species is via the external visible sexual organ of the males. In males, the posterior part of the anal fin is modified to a mating organ called andropodium. Only in one species, Z. quadrimaculatus, a melanophore pattern exists, all other species are silvery.

Recently we were able to import Zenarchopterus from Taiwan. According to Taiwanese literature, the only existing species of Zenarchopterus in Taiwan is Z. dunckeri. As we have no adult male in the import (the specimens are around 8 cm long) we were not able to verfy this identification, but have simply adopted the name.

Zenarchopterus are fascinating aquarium inhabitants that are swimming always close to the water surface. In the wild they feed mainly on land-insects that fall in the water, but in the aquarium they also feed happily on flake food. Against any tankmates these fish are very peaceful, but they tend to panic and thus should not be combined with “nasty” species. Most probably all species of Zenarchopterus are egg layers, but there is so far no detailed breeding report available. Zenarchopterus are typical estuarine fishes and thus prefer brackish water, although some species (among them Z. dunckeri) can be found far upstreams and others also enter happily the open sea. It is best to keep them in a salinity of 5-15 grams salt per litre.

For our customers: the fish have code 479304 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Zenarchopterus: ancient Greek, means “the one with a life-giving fin”, referring to the andropodium found in male fish. dunckeri: dedication name for Georg Duncker, ichthyologist in the Zoologisches Museum Hamburg, who discovered (among other species) the harlequin barb, Trigonostigma heteromorpha. quadrimaculatus: Latin, means “with four spots”.

Suggestion of a common name: Duncker´s river gar

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Taiwan
Verfügbare Größe in cm 8

Zenarchopterus dunckeri

21. March 2016

The wonderful, large halfbeaks of the
genus Zenarchopterus are only very rarely offered, because the animals
are very shy during the acclimatisation. When they panic they often hurt
themselves seriously. So we are very proud that we were able to import
successfully a small group of fully grown specimens of the species
Zenarchopterus dunckeri from Taiwan. The fish are currently about 15 cm
long. The group is formed of two males and three females. Despite the
very long gonopodium that clearly indicates an internal fertilization
the fish are – to the best of our knowledge – egg layers.

These fish need spacious aquaria, very
clean, bactertia-poor, hard water. The pH must be over 8. It is possible
to keep these fish, which are completely euryhalin, also in brackish or
pure seawater, but an addition of salt is not absolutely essential. The
fish prefer flake foods, but also accept other food items as long as
they are floating on the water surface. Once the food is sunken to the
bottom it becomes ignored. One should choose only absolutely peaceful
tankmates for cleaning the tank from sunken food – for example Corys –
because even harmless, but curious fish can literally (!) frighten the
halfbeaks witless! Once Zenarchopterus have settled they can live
happily many years in aquaria.

For our customers: the fish have code 479305 on our stocklist. Please note that we exclusively supply the wholesale trade

Text & photos: Frank Schäfer

Nomorhamphus celebensis

16. October 2015

Most
of halfbeaks of the genus Nomorhamphus originate from Sulawesi
(formerly known as Celebes). Some species, like N. ebrardtii or N. rex,
are traded usually as wild collected ones, others, among them N. liemi,
are occasionally also available as bred ones. A species that occurs
hardly ever in the trade is the Black Halfbeak, Nomorhamphus celebensis.
Currently we have some German bred ones in stock.

This
species is not as colorful as others, but comparatively very peaceful
instead. They tolerate as well conspecifics and other species in their
tank. During displaying the males of N. celebensis become jet-black.

The
males stop growing when they have reached a total length of about 6 cm,
but the females can grow up to a length of about 10 cm. If one wants to
breed these fishes the basic task is to save the offspring; the parents
are cannibalistic. One must never separate a gravid female too late; in
that case it will often give birth to dead youngs. And one must never
separate a gravid female too early, because these fish are quite lively
and need free space for swimming. So, even breeding the “simple”
livebearers is quite a tricky thing….

For our customers: the fish have code 438802 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Nomorhamphus liemi and N. ebrardtii

22. December 2014

The pretty halfbeaks of the genus Nomorhamphus reach us usually as wild collected fish from Indonesia. They originate from the island of Sulawesi (formerly: Celebes) where they inhabit preferably running waters. They like to feed very much on insects from the water surface, but they also take readily dried or frozen food. Males become usually 6-8 cm long, females become larger and can reach up to 10 cm. These fishes are livebearers. They do not require any special water.

Against conspecifics the males can be quarrelsome. One should either keep a good number of males (5 or more) or only one male per tank. Two or three males together do usually not good.

We most often receive these fishes as a mix composed of at least two species. This time the import contained Nomorhamphus liemi and N. ebrardtii. Both species can be told easily apart on the basis of the coloration. In N. liemi the males develop a fleshy hook on the tip of the lower beak. The size of this hook – in combination of the intensity of the coloration of the fins – shows which position in the hierarchy the particular male has. The big boss has the fattest hook, animals with a low rank have no hook at all and almost plain white fins. Females also have no hook. They can be easily recognized by the shape of the anal fin, which is a simple, normal fin in females, whereas in males this fin is modified into a complicated sexual organ, called andropodium.

For our customers: the animals have code 438832 (liemi) and 438822 (ebrardtii) on our stocklist. Please note that we exclusively supply the wholesale trade.
Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Indonesien / Indonesia
Verfügbare Größe in cm 5-6

Potamorrhaphis guianensis

26. September 2014

The needlefishes (Belonidae) are mainly marine fish. But there do exist three genera with a total of eight species in South America that live exclusively in freshwater. Among them the genus Potamorrhaphis is the most specious one: currently four acceoted species are known.

Potamorrhaphis can attain a maximum length of about 30 cm. Astonishingly these needlefish adapt very easy to the life in aquaria. They do not panic at all, what would lead to bad injuries of the sensitve beak. The fish must be fed in the beginning with live feeder fish (fish size 1-2 cm). Most needlefish can be trained to take sooner or later also frozen food.

Potamorrhaphis are social animals. It is fascinating to watch a school of these elegant predators. The Potamorrhaphis we currently could import originate from Peru. In that area the most recently described species P. labiatus occurs. But all features that can be examined on live fish externally fit better to the species P. guianensis in our fish.

For our customers: the animals have code 281534 on our stocklist. Please note that we exclusively supply the wholesale trade. Available in limited numbers only!

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Peru
Verfügbare Größe in cm 20-25

Dermogenys siamensis

3. June 2014

These tiny “pikes” are real wonders of nature. The fish become only 4-5 cm long. They obtained their popular name “halfbeak”, because the upper part of the beak is only half as long as the lower one. In Dermogenys this upper half of the beak is movable. It is used by the animals to catch their prey: small flies, pollen etc. that fall on the water surface. The fish prefer to swim straight under the water surface.

Dermogenys are livebearing fish and live widespread over southeastern Asia in freshwater. The males are very quarrelsome against each other and are used sometime for fish fights like the bettas.

Text & photos: Frank Schäfer

Hemirhamphodon phaiosoma

17. September 2013

For the first time ever we could import this very beautiful halfbeak from Indonesia. The halfbeaks of the genus Hemirhamphodon are adapted to blackwater in the wild. Thus they need – at least for the time of acclimatisation – very soft and acidic water. Maximum length of the species is around 6 cm (male), females stay smaller.

For our customers: the fish have code 421413 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Nomorhamphus rex

10. September 2013

This species of halfbeak from Sulawesi (formerly: Celebes) has been described scientifically only last year (2012). It can be distinguished most easily by the coloration from N. ebrardtii, a quite similar species (see http://www.aquariumglaser.de/en/nomorhamphus-ebrardtii_de_1519.html). N. rex has yellow ventral fins, N. ebrardtii reddish-orange ones, N. rex has a red lower beak, the lower beak of N. ebrardtii has the same coloration as the body, and N. rex has black bordered fins, which is lacking in N. ebrardtii.

Of course there are a number of other differences, but these are not visible in life animals. The most important one is the different structure of the modified anal fin in males, which serves to the internal fertilization of the females. This fin is called andropodium and has a species-specific structure which usually also hinders the occurence of hybrids.

The livebearing halfbeaks are kept best in larger groups (10 specimens or more), then they are comparatively peaceful against each other. Feeding is easy, for the fish take readily flakes from the water surface. Additionally one should feed freeze-dried food items. The fish feed usually on sinking food only when they feel absolutely safe.

Water temperature should be between 24 and 28°C, neutral or slightly alcalic water (pH between 7 and 8.5) is the best choice. Maximum length for the females is around 6 cm, males always stay smaller.

For our customers: the fish have code 438863 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Nomorhamphus: means “with about equal beaks”. ebrardtii: dedication name for “Geheimrat” (= privy council) Ebrardt. rex: means “king”; the name has been chosen because the teeth of the fish remind one to the teeth of the dinosaur Tyrannosaurus rex.

Suggestion of a common name: Red-black halfbeak

Angaben zum Tier
Herkunft Indonesien / Indonesia
Verfügbare Größe in cm 5-6

Nomorhamphus ebrardtii

27. August 2013

We imported very nice specimens of the halfbeak Nomorhamphus ebrardtii. This livebearing fish lives endemic (this means: exclusively there) on the island of Sulawesi, formerly known as Celebes. Here the species occurs mainly in smaller brooks. Maximum length of N. ebrardtii is around 6-7 cm.

The bright orange-red fins are very striking as well as the orange stripe on the belly is. However, the intensity of the colours depends much on the social postion of the individual fish. These fish have a strict hierarchy in both males and females. Only dominant specimens have the full strength of coloration. One should keep Nomorhamphus either by pair or in groups of 10 specimens upwards.

The fish need clean, oxygen-rich water. The pH should be neutral (around pH 7). They feed almost exclusively from the water surface. In the natural habitat they feed mainly on insects and most probably on pollen, on the aquarium they take readily food flakes (which should be rather small) and freeze-dried food items.

For our customers: the fish have code 438822 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexikon: Nomorhamphus: means “with about equal beaks”. ebrardtii: dedication name for “Geheimrat” (= privy council) Ebrardt.

Suggestion of a common name: Orange finned halfbeak

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Indonesien / Indonesia
Verfügbare Größe in cm 5-7

Hemirhamphodon kuekenthali

1. August 2011

Hemirhamphodon kuekenthali Hemirhamphodon kuekenthali

Gorgeous, large specimens of this livebearing halfbeak reached us from Borneo (Sarawak) recently. The species can hardly be told apart from the better known relative, H. pogonognathus. However, we have the feeling that it is a bit stouter. But our determination bases mainly on the origin (Sarawak).

Like all other Hemirhamphodon, H. kuekenthali is a pure freshwater fish that prefers soft and acidic water. Feeding the animals is very easy, as they accept readily any type of flake food or freeze-dried food. But one must keep in mind that the fish feed exclusively from the water surface. Fruitflies (Drosophila) are a delicacy for the halfbeaks.

Males of Hemirhamphodon are quite territorial, so it is wise to keep only one male per tank. The sexes can be easily distinguished by the shape of the anal fin. Males become about 6 cm long, females stay always smaller – at least this is true for fish in the wild. It is, of course, possible that they become a little bit larger in the aquarium.

For our customers: the species has code 421443 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Hemirhamphodon: from ancient Greek, means about “with teeth on the halfbeak”. kuekenthali: dedication name for Willy Georg Kükenthal (1861 – 1922) who discovered the species.

Suggestion of a common name: Sarawak Forest Halfbeak

Text & Photos: Frank Schäfer

Angaben zum Tier
Herkunft Indonesien / Indonesia
Verfügbare Größe in cm 6-8

Hemirhamphodon tengah

27. June 2011

Hemirhamphodon tengah Hemirhamphodon tengah

This pretty little fish is a challenge for experienced hobbyists. The species originates from Borneo. In contrast to the widespread prejudice halfbeaks of the genus Hemirhamphodon do not appear in brackish water; they are strictly bound to very soft and acidic water! These fishes are commonly found along with chocolate gouramis and small rasboras.

The other species of Hemirhamphodon are livebearers. Not so H. tengah: this is an egg-laying species. Breeding H. tengah is in most respects similar to breeding killifishes of the Apyhosemion-type. The females like to spawn in java moss, peat or in artificial breeding mops made of wool.

The fish are strictly surface-dwellers. They are not very demanding regarding food, but never take food from the bottom. So they should be fed with flakes and different types of live food. Small fruit flies (Drosophila) are a delicacy for Hemirhamphodon. Maximum length of the fish is about 6 cm.

For our customers: the fish have code 421552 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexikon. Hemirhamphodon: from ancient Greek, means about “with teeth on the halfbeak”. tengah: after the province Kalimantan tengah on Borneo, where the species has been collected initially.

Suggestion of a common name: Egglaying halfbeak

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Indonesien / Indonesia
Verfügbare Größe in cm 4 - 5

Xenentodon canciloides

18. January 2011

Xenentodon canciloides Xenentodon canciloides

The Needlefishes (Belonidae) are a relative small family and are represented by a small number (about 35) of species only, but these are very successful and can be found in marine and freshwater habitats of temperate and tropical regions worldwide. Some of them are so common that they form the basis of a commercial fishery for human consumption.

The Genus Xenentodon is restricted to tropical Asia. The fish are found exclusively in freshwater. They are unbelievable elegant predators that live near the water surface. In their natural habitat they are found always in schools. Currently only two species are accepted, namely Xenentodon cancila and X. canciloides. The beautiful fish we were able to import now from Thailand are closer to X. canciloides than to X. cancila, but may represent a still undescribed species as well.

Xenentodon can reach a total length up to 30 cm and thus should not be kept in too small tanks. Aquarists who want to keep these fish also have to guarantee the supply of the needlefish with small, life foodfish. If these preferences are assured, keeping needlefish is unproblematical. They even breed readily in captivity. The eggs have entangling tendrils and are placed in fine waterplants etc. The fish do not take care for their brood in any way. Males can be recognized when they reach sexual maturity (at a length of 15-20 cm): from that size on they have a red hump directly behind the head.

For our customers: The fish have code 476103 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Xenentodon: ancient Greek, means “with disconcerting teeth”; this applies to the lower pharyngeal plate. cancila: after an indigenous name for the fish in Bengal. canciloides: means “similiar to cancila”.

Suggestion of a common name: Inkstripe Needlefish

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Thailand
Verfügbare Größe in cm 10-15

Nomorhamphus liemi

30. March 2010

Nomorhamphus liemi Nomorhamphus liemi Nomorhamphus liemi Nomorhamphus liemi

 

This wonderfully coloured halfbeak originates from the island of Sulawesi ( = Celebes) where it occurs in the southern half. In contrast to the closely related genus Dermogenys the upper and the lower jaw are approximately equally long (thus the generic name). In some species, however, is seems not so clear whether they belong to Dermogenys or to Nomorhamphus.

There are two described subspecies of Nomorhamus liemi, eg N. liemi liemi with black fins and N. l. snijdersi with red fins. In our speciemens (wild collected) all intermediate states can be found, so it is not possible to apply a subspecies-name on them.

An interesting feature in N. liemi is the fleshy hook many specimens develope on the lower jaw. It is not known what it is good for.

In the wild, N. liemi mainly inhabit brooks and they like a relatively strong current in the aquarium. They are livebearing fishes, the females can give birth every 4 to 6 weeks. The young are very big, sometimes even 2.5 cm long! The mothers hunt their babies quite fiercely. Breeding will be only successful if the adults are properly fed; live insects (crickets, flies, buffalo-worms etc.) are an important part of the diet.

The water temperatures should be relative low (20 – 24°C), the pH higher than 7. Males are very aggressive against each other. Other tankmates are usually ignored.

For our customers: the fish have code 438833 on our stocklist. Please note that we exclusively supply the wholesale trade.

Lexicon: Nomorhamphus: from ancient Greek, means “with regular jaws”; this refers to the almost equally long upper and lower jaw, which is the difference to all other halfbeaks. liemi: dedication name. snijdersi: dedication name.

Text & photos: Frank Schäfer

Angaben zum Tier
Herkunft Sulawesi
Verfügbare Größe in cm 6-7

Potamorrhaphis guianensis

6. July 2007

Potamorrhaphis guianensis

These fish belonging to needlefish (Belonidae) reach the aquariums of interested hobbyists only very seldom. These robbers, called halfbeak, come from almost all over Amazonia. You can find them also in the Orinoco catchment area as well as in the Guyana countries. These specialized surface fish are only suitable for the the hobbyists with restrictions because of their rapacious habits. Especially regarding the nutrition they are making heavy demands on their nurse. In the beginning they mostly only react to living or struggeling prey and you should therefore already have built up a feedingfish breeding or you can feed them with living insects, which will be taken from the surface. The animals are particularly excited, if crickets, flies or insects like that touch the surface. After the settling you can try to get the fish used to dead food little by little. Especially frozen white blood worms are well-tried, as they are floating quite long in the water – too quickly sinking food is not getting noticed. They are rather undemanding to the further care, you only have to provide aquariums big enough for the surface robbers, which will grow to 40cm maximum and they feel best within a small group of 3-6 animals. Therefore aquariums having a base of 150x60cm are the absolute minimum. The height of the aquarium is not important as only the first 20cm und the waters surface are used as living space. A socialization is quite possible, but the other fish should on one hand not be one of their prey and should on the other hand not be so agressive that they could be dangerous for the peaceful Potamorrhapis guianensis.(Photo & Text von T. Weidner)

Angaben zum Tier
Herkunft Amazonasgebiet
Name Potamorrhaphis guianensis