Tag Archives: Paraguay

The sturgeon catfishes of Paraguay: Sturisoma barbatum or S. robustum?

14. January 2022

From Paraguay wonderful, partly very large sturgeon catfishes (Sturisoma) are imported. Two Sturisoma species are known from the Rio Paraguay: S. barbatum, described already in 1853 by Kner, and S. robustum, described in 1904 by Regan. The two species differ from each other only insignificantly. 

The most important anatomical feature distinguishing the two species is the structure of the nuchal and anterior dorsal shields. In S. barbatum, they consist essentially of three massive bone claspers (plus two smaller bone plates), whereas in S. robustum they consist of 17 bone plates.

S. barbatum is said to have much longer extended fin filaments than S. robustum. Today, however, we know that such fin filaments can be very differently pronounced both ontogenetically and individually and are not very suitable for species differentiation. If one looks at the illustrations attached to the original descriptions, it is also noticeable that S. barbatum (a male is shown) appears altogether more slender, the species name “robustum” is well chosen by Regan (a female is shown with him). In living specimens from Paraguay one sees very well that the males correspond better to S. barbatum, the females better to S. robustum. Possibly, therefore, S. barbatum and S. robustum are synonyms of each other. In that case S. barbatum would be the valid, because older name.

Our currently (2021/22) imported animals correspond to S. barbatum regarding the nuchal and anterior dorsal shields, as you can see well on the photos.

Sturgeon Catfishes are fantastic aquarium fishes that can grow up to 28 in length and require appropriately large aquariums. Males are easily recognized by their distinctive whiskers during the breeding season, but even outside of the spawning season it is not difficult to distinguish between the sexes, as can be easily seen in the photos. The diet is varied with a clear emphasis on plant foods.

With fish from Paraguay it is generally to be noted that the water temperatures there fluctuate seasonally and are quite low in the winter there. After successful acclimation the fish should be adapted to our seasons and kept at 24-26°C in summer and 16-18°C in winter. Then they usually breed willingly. They like to spawn at the front glass of the aquarium, the male guards spawn and newly hatched young. For the rearing of the young fish it is inevitable to feed excrements of the parents, because they need the bacteria and fungi (endosymbionts) living in the intestine to be able to digest plant food. If this is not observed, the young animals starve to death after the change from meat food (Artemia nauplii etc.), which they need as initial food, to plant food in spite of a full stomach.

For our customers: the animals have code 294805 on our stock list. Please note that we only supply wholesale.

Text & Photos: Frank Schäfer

Ancistrus sp. Paraguay

28. August 2019

After Paraguay had closed its doors for half a year for the export of ornamental fish, now imports from the southern country in South America reach us again. Among them also various Ancistrus species, which are often sent mixed. It has become common practice in the trade to call these animals Ancistrus tamboensis, which is objectively wrong, because A. tamboensis comes from the upper Ucayali basin in Peru, but nobody is actually bothered by it; one knows what is meant.

We have just received another import of such Ancistrus from Paraguay, among them also about 50 specimens in show-size (11-14 cm). Some males of these animals have such a huge “antlers” as we have hardly seen it even under wild collected animals so far! By the way: What this “antler” of the Ancistrus-males serves at all for is still unknown…

These “tamboensis” cannot be assigned to a certain species. In the catfish atlas volume 2: 274 top this species is called Ancistrus sp. Paraguay.

For our customers: the animals have code 205106 on our stocklist. Please note that we only supply the wholesale trade.

Text & photos: Frank Schäfer

Hyphessobrycon elachys

11. May 2018

Among the smallest species of tetra is Hyphessobrycon elachys, the veilfin tetra from Paraguay. The species becomes only 1.5-2 cm long (standard length without caudal fin). The charming animals inhabit swampy areas in the Rio Paraguay drainage. The genus Hyphessobrycon, as it is currently defined, represents an artifical assamblage of species which are not very closely related. So the placement of H. elachys in Hyphessobrycon is only provisionally and for sure it will be placed in another genus in case of a revision of Hyphessobrycon. The veilfin tetra is unique by the shape of the anal fin in males, the very long ventral fins in males and teeth structures.

In the natural habitat Hyphessobrycon elachys lives in mixed schools along with with other, very similar tetras and Corydoras hastatus. It is almost impossible to tell H. elachys from these other tetras apart on basis of the coloration. So imports of the species are always a mix, sometimes H. elachys is hardly represented in them at all. So to a certain degree there are always bycatches among H. elachys, but our current import contains at least 90% veilfin tetras.

For our customers: the animals have code 262052 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & Photos: Frank Schäfer

Corydoras longipinnis

12. February 2018

We were able to import an interesting Corydoras species from Paraguay, namely Corydoras longipinnis. This species has been scientifically described as recently as 2007 by Joachim Knaack. The new species is a close relative to the well known Corydoras paleatus and reminds one somewhat of the longfinned sport of that species. In Corydoras longipinnis only males develope long extended pectoral fins, whereas in the longfinned sport of C. paleatus also the females show that feature.

Corydoras longipinnis is a subtropical species and should therefore be kept at room temperature. For those who have the opportunity: it can be kept in garden ponds during summertime. Breeding C. longipinnis is easy and is the same as in C. paleatus. That means the fish must be fed heavily until the females show a swollen belly and then you have to change repeatingly a great amount of water and fill up with cool water (3-5°C cooler than the old water). This triggers mating and spawning.

Corydoras longipinnis should be kept in groups of at least 7 specimens. It is completely peaceful against congeneers and all other tankmates. The fish take readily any usual fishfood. Plants become not destroyed. The water parameters are of no great relevance. The pH should not be lower than 6 and not higher than 8.5.

A single bycatch is also very interesting. It is a specimen belonging to the species Corydoras ellisae. But while „regular“ C. ellisae show only two large blotches on a pale ground, this specimen imitates in a certain degree the pattern of C. longipinnis.

For our customers: Corydoras longipinnis has code 233552 on our stocklist. Please note that we exclusively supply the wholesale market.

Text & photos: Frank Schäfer

Literature: Knaack, J. (2007): Beiträge zur Kenntnis der Callichthyidae (Teleostei: Siluruformes). III. Corydoras longipinnis sp. n. – ein neuer Panzerwels aus dem río Dulce in Argentinien (Teleostei: Siluriformes: Callichthyidae). Vertebrate Zoology 57 (1): 35-55

Brochiloricaria macrodon

15. January 2018

We received from Paraguay this wonderful mouthbrooding whiptail catfish. Once we had this species even as bred ones in stock – many years ago. In our recent import the prolongations of the fins are very obvious. This reminds a bit in Lamontichthys. However, Brochiloricaria has a completely different mouth structure and feeding habit. Brochiloricaria are – like most mouthbrooding whiptail cats, rather interested in meaty food than in Aufwuchs. Our specimens are about 15 cm long. This means they are most probably only half grown, for there are reports of 30 cm long B. macrodon.

For our customers: the animal has code 210954 on our stocklist. Please note that we exclusively supply trhe wholesale trade.

Chaetobranchopsis australis

8. March 2017

Here it is: the cichlid with the probably most interesting mode of feeding from Paraguay! Chaetobranchopsis australis is specialized in feeding small planktic organisms. The up to 12-14 cm long fish swallows water like a vacuum cleaner and sieves the plankton with long gill rakers out of it. Obviously at the time of our importation – last september – the plankton in Paraguay is rather rare, for the fish are more skinny than we like it; but we are sure this has become corrected in the meantime in the fishhouses of our customers.

Chaetobranchopsis belongs to the very few species of cichlid in which the breeding behaviour is absolutely unknown. Aquarium fish have been observed in cleaning stones, so they might be open brooders, but no one knows!

For our customers: the animals have code 634904 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer