Shark catfish - Hexanematichthys seemanni
Scientific name: Hexanematichthys seemanni
Common name: Shark catfish
Usual size in fish tanks: 30 - 35 cm (11.81 - 13.78 inch)
Recommended pH range for the species: 6.8 - 8
Recommended water hardness (dGH): 8 - 30°N (142.86 - 535.71ppm)
0°C 32°F30°C 86°F
Recommended temperature: 22 - 26 °C (71.6 - 78.8°F)
The way how these fish reproduce: Spawning
Where the species comes from: Central America
Temperament to its own species: peaceful
Temperament toward other fish species: peaceful
Usual place in the tank: Bottom levels
The Shark catfish originates from Central and South America. They inhabit the coastal river waterways spending a lot of their life crossing from brackish to freshwater conditions.
This particular species of fish is known by many common names including the Columbian shark, Silver tipped shark, West American Cat shark and others very similar. They are often sold in the aquatic stores as juveniles, they are a very delicate species and due to bad advice are often kept in the incorrect conditions. As such they are often short lived in the home aquarium. If housed correctly adult specimens can grow quite large, mature males may reach an average length of up to 20 inches but most specimens will grow out at smaller sizes. This should be remembered when housing these fish and a suitable aquarium should be chosen to give them plenty of swimming space. They display a beautiful silver body colour which can appear to alter with the correct lighting conditions. They are renowned for their extremely peaceful nature and can be housed with other species of a similar disposition.
If cared for correctly the average lifespan for the Shark catfish is expected to be at least 10 years of age with some specimens outliving this by many years.
It should be noted that the shark catfish is a very delicate species so should never be added to an immature aquarium setup. They should also be acclimatised slowly so that they do not suffer from shock when being introduced to the water parameters. The minimum sized aquarium that should be used will need to be capable of holding at least 75 gallons in water volume for a single adult specimen. If you are keeping more then the aquarium size will need to be increased accordingly. They require lots of swimming space and carefully research these fish before purchasing they are not ideal for novice fishkeepers. Juveniles in the wild are raised in brackish water conditions so they are not a true freshwater fish although adult specimens will cope with this much better. The water temperature should range between 22-26°C (72 -79°F) and the pH should range between 6.8-8.0. Sand should be used for the substrate, coral sand will help with the pH range. Decoration is optional but leave plenty of open spaces in the bottom levels of the aquarium.
They can be housed with other species of a peaceful disposition but avoid keeping them with small species of fish as these will be seen as a food source.
The shark catfish will develop spines on their dorsal fins so take care if handling or performing tank maintenance.
These fish spend a lot of time around the substrate looking for scraps of food, however some keepers have reported them feeding for the water surface. They will accept sinking pellets and quality flake. This should be supplemented with live or frozen foods such as blood worms, chopped cockles or brine shrimp.
As juveniles there are no physical differences between the sexes. As the mature females will develop lighter finnage compared to mature males.
Unless you are a specialised breeder, it is extremely difficult to breed these fish. The main problems arise as young juveniles require brackish water conditions but as they develop they are slowly introduced to freshwater surroundings. It is known that they are paternal mouthbrooders, the female only lays a small amount of eggs with each spawn. The male will then incubate these eggs in his mouth and will perform all the parental care for the fry when they hatch.
Bought by aqua-fish.net from jjphoto.dk