FLYING FOX
6Scientific name: Epalzeorhynchos kalopterum
6Pronunciation: Ay-pal-zay-oh-rin-koss kah-low-puh-ter-um
6Size: To 16cm
6Origin: Mainly Thailand but also Java, Sumatra, Borneo and
Malaysia
6Habitat: Sandy and rocky streams
6Tank size: 120x45x30cm
6Water requirements: Slightly soft and acidic to alkaline water;
5.0-7.5pH, 2-12°H
6Temperature: 20-25°C
6Temperament: May attack any fish that
looks like itself in a confined space
6Feeding: Aufwuchs, algae and crustaceans in the wild, takes well to flake and pellets in aquaria
6Availability and cost: Less common nowadays as most stores carry
Crossocheilus species instead. Expect to pay £7.50 or so for a quality specimen
tanks with aggressive and dominant fish, and they do so successfully.
The loach keepers refer to their aggressive loach aquariums as ‘Grrr’ tanks, usually containing Syncrossus and Yasuhikotakia species, and for these they set up large tanks with flow and abundant hiding spaces, retreats and décor for territories.
Similarly, the Rift Lake cichlid keepers do likewise with their tanks, stocking so densely that no fish can establish enough of a territorial boundary to become dominant, and so that hostilities are diluted down in all directions so that no one fish is picked out and bullied constantly.
The same applies to sharkminnows. In groups they lose a lot of the aggressive tendencies and territorial dominance, and aside from the occasional squabble they do become a lot more subdued. I believe we need to look at much larger tanks than are currently being recommended. The usual suggested aquarium dimensions are around 90-120cm long by 30-45cm wide, based around the single specimen ‘rule’.
If we go bigger still, doubling the footprint, then we are looking at an aquarium 180-240cm long by 60-90cm wide. Additional water depth is a bonus, as if aquascaped well the fish will utilise all levels of the space — while touted in much literature as bottom dwellers, in the right setting they are far from such. By adding in lots of wood roots and branches, rocks and other decorative items we provide retreats and areas for the fish to utilise, as well as breaking up lines of sight without taking up too much swimming space. Plants are optional and can help define boundaries and provide refuge. Substrate can be sandy or fine gravel.
Just avoid anything too sharp. Looking at the natural habitats these fish come from in Thailand, Java, Sumatra and Borneo and the Malaysian peninsular reveals a small variety of habitats. Mostly riverine living, they inhabit slow- to fastmoving rivers, basins and streams
in the wild, moving with the seasonal flows into floodplains and other areas and back again. Websites like Mongabay.com or biotope-aquarium. info will help provide you with information and ideas.
Biotopes are quite rightly all the rage at the moment so an aquarium offering areas of high, medium and low flow will suit them best in the long-term. Using circulation pumps and powerheads designed for marine aquariums will give the required flow. Powerful filtration and regular water changes will keep dissolved organics, nitrates and other dissolved solids low, and that’s definitely the order of the day. Large powerful cannister filters and/or sumps will help achieve this. Water chemistry for all in the genus is pretty similar; a temperature of 20-26°C, a pH between 6.0 and 7.8 and a hardness of 36-250ppm will be fine.
Red tailed black, Rainbow and the Flying fox
Epalzeorhynchos bicolor, the Red tailed black shark (or just RTB in lazyspeak) is perhaps the most well-known ‘shark’ in the hobby, with a jet black body and a bold fire-red tail. It’s deeper bodied than other species in the genus and a good specimen can be a striking fish, especially when mature.
Upon close inspection the body actually has an iridescent green sheen and the caudal fin colour ranges from orange to deep red.
It is quoted in literature as reaching 10-15cm in length however there are verified fish reaching 17.5cm or more SL. There is an albino form, although this is much rarer in the shops than the standard colour form.
Females are much deeper bodied and more rotund than males, but breeding is practically unknown in the hobby; however, this could well be down to the fact that they are routinely kept singly. Back in the 1950s to 1970s they were more commonly kept in groups and there are reports in various publications from that era about them being cave spawners where the male tends to eggs that hatch after 30-60 hours. The next fish is Epalzeorhynchos frenatum, commonly known as the Rainbow, Ruby or Red-finned shark. More streamlined and torpedo shaped than E. bicolor it is still a beautiful specimen in its own right ‚ with an iridescent sheen of green on a dark grey body, and with bright red fins (not just the tail) it again is a stunning fish to behold.
An albino variety is quite common in the hobby, and while illegal in the
UK, a ‘glowing’ GM version has been manufactured abroad.
It is worth noting that an extremely similar species, E. munense, exists but is not often seen in the trade. The body is smaller, darker brown/grey and the fins are darker with only the black edged pectoral and caudal fins being bright red and the anal, pelvic and dorsal fins being darker and carrying a red tinge. Again, there is an albino variety. There is also the chance that being closely related and similar, hybrids of these two species may have been created and traded due to the hormone breeding techniques used in farming.
The last species of Epalzeorhynchos that’s readily available is far easier to tell apart from the other sharks due to its very distinctive pattern (although it is then confused with other similar looking but distantly related fishes).
Known to many as the Flying Fox, E. kalopterum has a torpedo shaped body with a cream-coloured bottom body with a bright, iridescent gold stripe and dark black/brown stripe running from eye to tail and a dark top. The fins are dark brown/black edged with red and with bright white tips. Modern literature claims they are perhaps the most aggressive of the genus, yet in my experience they are no more aggressive than any of the others.
The (not) Chinese (not very good) algae eaters
A misnamed fish from the start, as they are not from China but from Thailand, gyrinocheilids such as the Chinese algae eater, Gyrinocheilus aymonieri, and their lesser-known relatives are bought by millions to keep algae under control.
Whilst they may work well at this when really young and small, as they mature, they become much more territorial, dominant and aggressive and can damage, stress and even kill other fish due to this behaviour; of all the fish here, this one does warrant its reputation as a hostile bully.
In the wild they are solitary and patrol territories that can be many meters square in fast-flowing streams, strewn with gravel and rocks covered in biofilm and algae.
Sucking loach require a larger aquarium than any of the others mentioned here, and that’s just as solitary specimens — an aquarium
They inhabit slow- to fast-moving rivers, basins and streams
for a group would need to be larger than most houses.
Capable of reaching up to 30cm, and being a stocky and strong fish that can live a decade or more, a group will require careful consideration and be a challenge to keep. These fish are mass bred with hormones for the captive trade, and are more commonly available in an alluring gold colour than they are in their standard dress.
Males will develop tubercles on their head when mature and females will be noticeably rounder when ripe with eggs but there seem to be no known breeding reports and very little is known of breeding in nature. What we do know of them is that they are prone to attacking most tankmates, and there are many legends of them behaving like domestic lampreys, sucking on to the likes of Angelfish to cause considerable damage.
Handle with care.
in the wild, moving with the seasonal flows into flood plains