“Sharks” and Flying Foxes
Both “Sharks” and Flying Foxes are popular in the aquarium hobby. The best known are Epalzeorhynchus bicolor (still, incorrectly, known as Labeo bicolor) (Red-tailed Black Shark), whose striking coloration-velvety black body and scarlet caudal fin – is all that is needed to sell it; and Epalzeorhynchus frenatus (formerly Labeo frenatus) (Red-finned Shark, Ruby Shark) which has, as one of its common names suggests, red fins and a dark brown body. The “shark” part of their common name derives from their shape and the manner in which they swim, cruising the aquarium in a sharklike manner, and not from their eating habits! Although popular, they are not ideal community fishes. Both can be quite belligerent and will pick on other fishes, as well as each other, shredding fins and generally bullying them. When fully grown at about 12 cm (4 3/4 in) they can really cause a lot of damage, so keep them only with other fishes large enough to take care of themselves, such as the mediumsized barbs and cat-fishes. True omnivores, they will eat anything.
Far less trouble, though larger, are Balantiocheilus melanopterus (Silver or Bala Shark) at 35 cm (14 in), Labeo barbusfestivus (Diamond Shark, Festive Apollo Shark) at 20 cm (8 in), and Osteochilus hasselti at 30 cm (12 in). Although these are large fishes, they are peaceful. Many people often keep juvenile specimens in their community tanks, acquiring larger accommodation for them as they grow. Given plenty of space, growth is steady. They like clean, clear water with a reasonable flow, such as that from a power filter. Feeding is no problem: they are omnivores but do have a liking for green foods and will graze on algae or nibble at plants. Osteochilus hasselti is particularly fond of Java moss and will keep the rampant growth of this in check. If you do not have many plants in the tank or if the fishes are grazing too heavily on them, lettuce leaves make a good alternative. The fishes tend to ignore them if they are left to float but, if planted they are classed as fair game and eaten. Do ensure that you have a good cover on the aquarium as these fishes will jump, especially if frightened.
Members of the genus Labeo are generally referred to in the trade as sharks. For those of you who like big fishes, Labeo chrysophekadeon (Black Shark) may be worth considering keeping. Growing to 60 cm (24 in), this deep-bodied shark is a very powerful, active creature that can be quarrelsome, so is best kept alone. Even at half this size it requires a 100 x 50 x 50 cm (36 x 18 x 18 in) aquarium and a filtration system to match. Unless you feel you can cope with this, it is best left to public aquaria to maintain. It is omnivorous but likes a predominance of vegetable matter in its diet. In southeast Asia the flesh is considered to be very good eating, and it is an important food fish. There is a small African Labeo that is highly prized among aquarists, Labeo variegatus (Harlequin Shark, Variegated Shark). Growing to only 30 cm (12 in) at most, it is much more manageable and much more attractive as a juvenile. Youngsters are mottled dark brown over a light cream to beige background and there are traces of orange/red in their fins, but as the fishes mature they lose this colouring and turn grey. Small specimens tolerate other fishes but they can become aggressive when mature. It is one of those fishes that are best grown up along with their tankmates rather than trying to introduce medium- to large-sized fishes into the adult shark’s territory. An omnivore, it is no trouble to keep or feed.
Epalzeorhynchos kallopterus (Flying Fox) is an ideal fish for the larger, well-planted community aquarium. Although loners, several specimens can be kept in the same aquarium without fights breaking out, provided they can define their territories. Flying foxes are almost too good to be true: they are tolerant of other fishes, graze algae but do not chew at the nplants, and are tolerant of most water conditions as long as extremes are avoided. Their occasional tendency to dash around may, however, be unsettling for some timid species.