Admiring Aphyosemion australe
Author: Tony Pinto
Sometimes life can take some really strange turns when you are a diehard killifish addict (keeper). At the Canadian Killifish Show and Auction over the Labor Day weekend in September 2000, I came close to missing my plane while bidding on a nice young pair of one of my favorite killifish: the chocolate form of the Cape Lopez lyretail (Aphyosemion australe).
There were three pairs of a new population (labeled as location BSWG 97/24 originating from Port Gentil, Gabon) that had been imported from Europe for the auction. As they were a new population to the killifish hobbyists in Canada and the USA, there was spirited bidding for the first pair. I was fortunate enough to win the bid for that pair but then had to race to the airport to catch my plane home.
The fish made it back safely, and within a few weeks I was delighted to have a few eggs and see fry swimming in my tanks. Nothing to it, I thought, when breeding the Cape Lopez lyretail killies. I found that I was very lucky with my fish, however, as a friend who bought another pair at the show had less success with them. Luckily, I was able to send him eggs and fry the following year when the cold winter ended.
Aphyosemion australe Origins
The Cape Lopez lyretail has been known to the aquarium hobby for more than a century. It is very popular, along with other well known species like Fundulopanchax gardneri, Aplocheilus lineatus, and Aphyosemion striatum. It is an excellent beginner's fish, and many experienced killie keepers (killinuts) will suggest that a new killie keeper should try working with this species, as it is easy to keep and breed successfully.
As so often happens, there have been a number of name changes since this fish was discovered. The first importation of the species took place in Germany in 1913, when Arnold & Cramp described the imported specimens as Haplochilus from Kap Lopez. Rachow proposed the name Haplochilus calliurus var. australis for this fish in 1921. And, in 1924, Ahl described Panchax polychromus from 27 specimens said to have been collected in the Cape Lopez area of Gabon. Later investigation proved them to be an aquarium population of A. australe.
Öser collected this species at Port Gentil in Gabon in 1928 while traveling on the German merchant ship Waganda, and these fish were imported alive into Germany. Thus our aquarium-strain lyretails have been circulating in the hobby for a very long time.
The fish appears to be distributed around the coastal forest areas from northwest Gabon to the southwest Congo. There is also considerable color variation in the species; some populations show more vivid colors while others lean towards being plain. Descendants of wild populations of A. australe in the hobby at present include those from Port Gentil (location code BSWG 97/24), Cape Esterias (location code EBT 96/27), and Parq du Mondah (location code BDBG 04/19). The location codes refer to the last initials of the collector(s), the geographical code, and the year of the collection.
The base color of the male fish is brown on the body with a lot of red spots and markings. The area behind the head is a bright iridescent green. The anal, caudal, and dorsal fins are a pale brown with lots of red dots; the fin rays on the anal and dorsal fins are often extended on older males. But it is the beautiful lyre-shaped caudal fin that gives the fish its name of lyretail; the white fin extensions can extend for as much as ¼ inch (6 mm) or more. Like the majority of killifishes, the females are drab in comparison, being a darker brown with fewer red spots on the body and the unpaired fins–the caudal is rounded and doesn’t show the long extensions seen in the males.
An orange- or golden-colored variation shows up in this species too; this is simply a mutation of the chocolate form of A. australe, not a separate subspecies. Here the chocolate brown colors on the body are replaced by a bright orange. This orange variant was described in 1953 by Meinken as A. australe hjerreseni (after the breeder Hjerresen, who discovered the first orange specimens in his collection), but the name is not valid. These fish are certainly more attractive than the original chocolate strain, and some breeders produce exceptional strains of this variant.
Killifish species closely related to A. australe include A. calliurum, A. celiae, A. ahli, A. pascheni and the recently described A. campomaanense.
Perfect for a Community Tank
Cape Lopez lyretails can be can be maintained in community aquaria, as I have found them to be quite peaceful towards other species of similar size. Bigger males will chase the smaller ones, but not much damage takes place. It is preferable not to add more aggressive or fin-nipping fish or the beautiful tail extensions of the males will disappear under such conditions. Suitable companions include small peaceful tetras, rasboras, and barbs.
Lyretail killies are not shy. They will readily display, and they come to the front of the tank when they think their owner is going to feed them. Unlike the South American Rivulus species, the lyretails are not jumpers, but it is better to be safe by keeping a cover at the top of the tank to avoid unhappy accidents.
A. australe seems to prefer soft water, to which I add a teaspoon of aquarium salt to every 10 gallons (38 liters) of water. Very hard water conditions should be avoided as much as possible, because though the fish might survive, they will not breed successfully. A pH from 6.5 to 7.0 seems ideal for them. I have found the optimum temperature to keep these fish is anywhere from 76° to 78°F (approximately 25°C). As with most other killies, live foods are preferred, although I have “trained” my fish to take crumbled flakes, micro pellets, and frozen foods too.
Easy to Breed
It is due to the ease of maintenance and breeding in the aquarium that this killifish is considered a favorite for beginners. I find it preferable to put a pair or trio into a small 5-gallon (19-liter) tank for a week with one or more dark colored acrylic spawning mops, and then collect the eggs over a week or two. Feeding live foods to the breeders will result in more eggs being produced. The small round and clear eggs (1 mm in diameter) can be collected from the mops and incubated in water; they hatch within 10 to 20 days. Alternatively, they can be stored in damp peat for approximately three weeks at 76°F (25°C) and then the peat is made fully wet, which causes the fry to hatch.
If the eggs are collected and stored in water, the aquarist can monitor the developing embryos and the eventual hatching. This water method allows any white eggs (infertile or fungused) to be removed, but collecting eggs can be slow and tedious.
In the case of peat, I simply put a small quantity of peat or peat fiber on the bottom of the tank and then harvest it after a week or two. If the breeders are well fed, I can be reasonably sure of getting anywhere from 40 to 60 fry. The damp peat method gives me a uniform hatch, with all the eggs hatching in 24 to 48 hours. Are there some that do not develop and stay clear? Yes, I have found undeveloped eggs once in a while. I think of the peat method as a mechanism for nature to keep the species going in case the water levels get dangerously low, with the adults dying off and only the eggs surviving.
Caring for the Fry
Fry will also turn up spontaneously in the parents' tanks if there is adequate live food for the parent fish. They usually appear as small black slivers in the dark corners of the tanks. They need infusoria for the first week, and then they start to take newly hatched brine shrimp and microworms. They tend to be very shy at first and dash into the darkness at the first sign of danger–real or imagined. But with good feeding and water changes growth is quite rapid; it is not uncommon to have the fry growing to ½ inch (1.2 cm) in six to eight weeks.
At that time it is usually wise to start sorting out the larger fry from the smaller ones to avoid any cannibalistic tendencies. The fry show female coloration initially, and then the young males start to develop the characteristic extensions in the caudal fin. I tend to separate the fry based on their sex when the sexes become distinguishable, because the more aggressive males tend to out-compete smaller females for food, and there is a danger that I might end up with very few females. The sex ratios tend to be quite even.
This is a very pretty, active killifish that deserves the widespread popularity it enjoys in the aquarium hobby. Unlike annual killifishes, the species is fairly long in the aquarium, usually for two to three years. It is no surprise that both the chocolate and orange mutations of this species will continue captivate future generations of aquarists!