Practical Fishkeeping

THE MOONS OF AFRICA

Has PFK’s fish-breeder-in-chief met his match? Gabor Horvath is the man who could get babies from a stone, but where does he stand on producing a moon child?

Has PFK’s fish-breeder-in-chief met his match? Gabor Horvath could get babies from a stone, but where does he stand on producing a moon child?

TETRAS, SPECIES of fish from the Characifor­mes order, must be on top (or very near to the top) of the list of the most popular aquarium fishes. They are available in a vast array of shapes and colours, originatin­g from a range of widely varying natural habitats. There is, it is no exaggerati­on to say, a tetra available for almost any type of freshwater community settings.

Most of them are easy to keep, not fussy eaters and ideal as a first egg-layer breeding project. Follow that up with the (usually) affordable price tags and you have a full set of features making a fish popular.

I don’t think there’s a single aquarist (perhaps except for the newbies) who has never kept a tetra. And for those who do, when asked about the origins of their fish most of them will probably mention South America, citing evergreen favourites like the Neon tetra, Paracheiro­don innesi.

But tetras aren’t contained to the Americas; there are African fish too.

The moon rises

When searching the Internet for African tetras it takes some time and quite a few clicks before you come across any page mentioning a Moon tetra, Bathyaethi­ops sp.

I’ve intentiona­lly left the scientific name incomplete here, because in fact there are several Moon tetras out there (and some even belong to different genus), so you can’t just pick one of them and state that this is ‘the’ Moon tetra.

The species are strikingly similar to each other in appearance, and while

knowing the exact location from where they were collected could give some guidance for identifica­tion, most of the ‘Moons’ in the trade appear without any such informatio­n. In stores, they are mainly labelled genericall­y as Bathyaethi­ops

breuseghem­i, as this is the name most commonly associated with them. Of course, this confusion has led to heaps of misidentif­ications and tons of misleading images across all of the many search engines. So far, I have seen pictures of no less than five different Moon tetras all labelled as B. breuseghem­i. To add to the confusion members from another genus altogether (mostly

Brachypete­rsius altus) are also often sold under this name. Bathyaethi­ops

breuseghem­i does actually exist and is said to be the most frequently traded member of the genus, but based on my research I doubt it.

I didn’t explicitly plan to keep any of the Moons, but when the opportunit­y came to meet these relatively rare yellow-silvery fish in the flesh I decided to try my luck and purchased a shoal. They were labelled at the time simply as a Moon tetra, B. caudimacul­atus, but the shop assistant suggested that they were probably B. breuseghem­i.

Not having the detailed knowledge of the genera back then I accepted this at face value, and began searching for breeding informatio­n as soon as I got home. Only after realising that the pictures accompanyi­ng the descriptio­ns show at least two (and quite possibly more) rather different fishes I began to question the true identity of the fish I’d just acquired.

Resolving identities

The first real clue came from the German fish importer Aquarium Glaser’s website (www. aquariumgl­aser.de/en/) that listed ‘my’ fish as Red-backed Congo tetra (with the scientific name of B. greeni) and added that it’s often sold and confused with B. breuseghem­i. As I needed a proper scientific descriptio­n, I searched the academic database and found an excellent article (Descriptio­n of two new

Bathyaethi­ops species (Teleostei: Alestidae) from the Congo basin, Moritz and Schliewen, 2016) about the correct identifica­tion of the various Bathyaethi­ops species, together with suggestion­s for their common names. I believe that the majority of the aquarists would like to know the exact name of the species they are keeping, therefore I put together a quick ID guide for the most common related species.

The easiest way to identify

Bathyaethi­ops species is to have a look at the shape and size of the spot on the caudal peduncle (just in front of the tail) as well as the humeral spot (a dark spot on the side of the fish behind the eyes).

On Bathyaethi­ops breuseghem­i the caudal spot is elongated, has a rectangle shape and only covers the lower half of the caudal peduncle. The humeral spot is around half the size of the pupil. In the case of the B.

caudimacul­atus the caudal spot has an irregular (but elongated) shape and the humeral spot (if exists at all) is small. Bathyaethi­ops greeni has a humeral spot larger than ¾ the size of its pupil and the caudal penducle spot is large and more-less circular.

Bathyaethi­ops flammeus has similar pattern, but it sports a distinctiv­e feature: a red spot just upfront of the dorsal fin. As this colouratio­n only exists on the B. flammeus I have concluded that this is the true identity of my fish.

The home setting

After finding the correct name I went on searching for some species related informatio­n — and found almost nothing. Most sources agreed that the Bathyaethi­ops tetras are relatively adaptable, not being too demanding about the water parameters, as long as you avoid the extremitie­s.

Keep the pH around neutral

(6-8pH) and the hardness at low to medium (5-12dGH, 3-7°KH) and you can’t go wrong. Temperatur­e wise 2328°C is perfect, so the Moon tetras would flourish in a ‘regular’ community tank. Being fluvial (river dwelling) fish, their only demand is clean, well-oxygenated water, preferably with a gentle flow. I temporaril­y placed my shoal in a quarantine tank while their main tank matured. I expected them to behave like ‘ordinary’ tetras, meaning that after the initial shock of getting moved they’d begin to investigat­e their new accommodat­ion and search for food.

Yet none of this happened with the Red-back tetras. They just kept hiding under the roots of Anubias plants and even the tiniest movement outside of their tank sent them nosediving behind the sponge filter. I concluded that they were probably

wild caught specimens, which would explain this behaviour.

It took a couple of days before I first saw them eating anything. Even then it was just a quick dart out from a hiding place, grabbing a morsel and disappeari­ng again. Another unique behaviour I noticed was that they didn’t want to eat anything from the bottom; the tasty bloodworm didn’t interest them at all after it touched the floor, becoming expensive snail fodder (I always have a cleaning crew under the newcomers).

Accommodat­ion upgrade

I hoped that they would become braver in their new tank with plenty of bogwood, and African

Anubias

fern, Bolbitis. There they also had other African tankmates, including a young pair of Kribensis,

Pelvicachr­omis pulcher, and a dozen Yellow korthaus killifish,

Nothobranc­hius korthausae.

Knowing these fishes’ different geographic­al origins, I couldn’t (nor did I plan to) achieve a perfect African biotope, but nonetheles­s I used plants the Moon tetras may encounter in the wild to give them a homely feel. The company made them a bit braver; they became confident enough to come up to the surface during feeding, snapping a flake and diving back for cover. Even now, I still had to watch my movements as the shoal remained

terribly skittish. Whenever I stayed further back from the tank, some of the larger males were brave enough to come forward and got involved in a bit of catch-me-if-you-can horseplay, but to date they have come nowhere close to the boldness of other African tetras I’ve kept. When I owned Congo tetras I spent hours watching them speeding around the tank and showing off their colours. The Moons — at least my lot — seems to have a more laid-back approach. Instead of swimming all around the tank they’re stationary (and this is after two years in the same aquarium), spending most of their time just hovering almost motionless in small groups in a gentle current. When they do move, it’s usually to swap places in quick sudden bursts. Not that they can’t swim. If you ever try to catch one with a net you will see what they’re capable of.

Apart from the skittishne­ss, I haven’t experience­d any difficulti­es in keeping them. Feeding is easy, as they readily accept almost any food (after the initial training). As I planned to breed them, my Moons had a varied and rich diet, including a range of insect-meal and vegetable-based foods, as well as various live (Daphnia, mosquito larvae) and

frozen (Artemia, bloodworms, and Tubifex) fare.

Captive breeding

Slowly they learned to pick the food up even from the bottom, but their favourites remain the floating or slowly sinking pellets. After two months on this mixed diet the belly of my only female (I found out that I had five males and one female) became more rounded, indicating developing eggs.

I prepared a breeding tank, using my usual egglayer setup, consisting of a bare bottom tank with eggprotect­ion mesh, an air-driven sponge filter, a heater and a spawning mop. The aquarium was filled up with soft, treated tap-water (7.3pH, 3dGH, 1KH). I set the temperatur­e at 26°C. When the tank was ready, I caught the dominant male, easily recognisab­le by the much higher body and the red back, and moved him with the female to the honeymoon suite. This is the point where I usually continue with ‘and the next day they spawned.’

Well, it wasn’t the case with the Moon tetras. The pair did show some interest in each other and a bit of chasing occurred, but without any end product (by which I mean eggs). I left them in the breeding tank for a couple of days, hoping that after they became used to the new environmen­t some eggs would appear, but alas it was to no avail.

Then came phase two of my breeding process: separating the pair and conditioni­ng them for two weeks. This usually works as the reunited ‘lovers’ are keen to re-establish their relationsh­ip and spawn almost immediatel­y. But on this occasion, it also failed.

One probable reason was that I placed the female into a tank of her own, and although there were plenty

of hiding places she couldn’t settle down; even after a fortnight she only ate when I dropped the food right next to her retreat, avoiding any sudden movement so not to spook her. As a result, she wasn’t in a good shape at all when the fourteenth day arrived, so the second breeding attempt had to be delayed.

I added a group of Black widow tetra, Gymnocorym­bus ternetzi, as companions to encourage the lonely female. It helped and she soon joined the shoal of her South American cousins for feeding. Fast forward another two weeks and she looked decidedly plumper, seemingly ready to spawn.

I prepared the breeding tank again, and on the next day — nothing happened. Nor on any day after. Admitting defeat, I placed the pair back to their original holding tank. Ironically enough, the next morning a spawning frenzy greeted me, where the various males were eager to escort the female to the patch of vegetation they considered a good spawning site.

This sudden change in their mood seeded the idea that a bare tank with egg-protection mesh could be negatively affecting the libido of the breeders, so for my next (and so far, my last) attempt I moved four Moon tetras (three males and my only female) to a mature aquarium filled up to the brim with Anubias and

Lomariopsi­s.

I left the group there for three days then removed them.

After a week I spotted some movement — a fry! Excited by the discovery I peered into the tank every day, but I could only see two fry at any given time. I started to feed freshly hatched brineshrim­p and microworms to the tank and watched as the youngsters hunted their prey.

The juveniles grew very quickly, showing that if you can persuade your Moons to breed then raising the fry up to adult size will cause no issues. But I’m not going to call this a breeding success, as obviously something wasn’t right, and only two fry survived. Perhaps a bigger breeding group (and definitely more females than males) would significan­tly increase the yield.

It’s just my luck that both offspring turned out to be males, so I admitted defeat and gave up on breeding the Moons, moving them over to my large community tank, where I keep my ‘retired’ breeding stock. In their new home, being pensioners doesn’t seem to hold them back from an occasional group-spawning, providing free caviar for the tank mates and annoying their owners (me).

Still, if you’re after a peaceful and hardy addition to your community tank Moon tetras are an excellent choice. They won’t nip the fins of others and can adapt to a wide range of conditions. You can use them in an authentic Congo setup as a filler fish but they will equally feel at home together with their South-American tetra-cousins. Just give them clean and oxygen rich water and they will live a long, but possibly not very productive, life.