NOTHOBRANCHIUS FUSCOTAENIATUS

 

By Jesper Thorup 2003

When it comes to Nothobrancius species, peoples taste end preferences are fortunately not the same. This is how it is supposed to be, as it assures that there are a good number of species that are kept and maintained in the aquarium hobby at any given time. In the spring of 2001 I got a portion of eggs of Nothobrancius fuscotaeniatus "Kitonga north, TAN 97/9" send from Julian Haffegee and ever since this species have been one of my absolute favorites.
 According to the first description of the species by Lothar Seegers, which can be found in "Killifishes of the World, Old world Killis II" on page 12, N. fuscotaeniatus is the only Nothobranchius species were there are no red pigmentation on the males body and fins. The species is also supposedly unique because the females as the males have vertical black stripes on the body, only the females typically only have them on the tail half of the body. These stripes are the reason for the name of the species as fusco means dark and taenium means striped.
 N. fuscotaeniatus has as most others in the genus a maximum size of 4.5 to 5.0 cm, but the body shape is different from what is usual for the genus. It is almost shaped as a torpedo with a pointed head and the point were the body is widest, is located just in front of the offset of the dorsal and anal fins. The base color is, when the species are kept in fish tanks, mostly blue with hints of green shades. Also the females can have this body coloration which is uncharacteristic for the genus. This makes it difficult to determine the sex of young individuals.

The species was first caught by Watters, Wildekamp & Cooper, late in the afternoon on May 31st 1997. The place were they caught the fish is stated to be close to the village Kitonga in Tanzania and for this reason the species was given the temporary name: "Nothobranchius spec. "Kitonga north, TAN 97/9". On the same spot they also found N. lourensi and N. janpapi which was therefore given the same code. On the 22nd of July the same year Lothar Seegers caught the new Nothobranchius species along with the same two other species. His fish was given the code: "TZ 97/57".

It has since been discussed if there really was two different places were this species was caught or not. Have a look at e.g. Marc Bellemans homepage. He place the Watters, Wildekamp & Cooper collecting point about 80 km north of Rufiji River close to Mbezi River. The confusion seems to be caused by the fact that the name "Kitonga" is very commonly used to name towns all over Tanzania and therefore making it hard to determine the actual spot using maps.

According to Brian Watters, the town on the southern bank of the Rufiji River by the Ndundu ferry crossing is called "Kitonga". The town on the northern bank is called Ndundu. It was along the road, 2 km south of this "Kitonga" that Watters, Wildekamp & Cooper first caught the fish. This is also confirmed by Finn Larsen in his article "Tanzania 1998" were Brian Watters, along with Mick Agnew, Finn Larsen and John Rosenstock are on their way to the Ndundu ferry crossing to go fishing at the collecting point "Kitonga North, TAN 97/9" south of the Rufiji River. This was impossible because of flooding and they have to go back north. The description of this point is completely consistent with Seeger's information: "About 2 km south of the Ndundu ferry, across the Rufiji River on road from Nyamwage to Kibiti." There should therefore not be any doubt that the N. fuscotaeniatus "Kitonga north, TAN 97/9" and N. fusco-taeniatus "TZ 97/57" was actually caught on the same spot.
 Even though Seegers had a couple of months delay catching the new Nothobranchius, he was first to describe it. He followed his first description up with a longer article, which was published in the German aquarium magazine DATZ in 1998, were he amongst other things describes the habitat. It was a two meters by ten meters pond that was 60 cm deep at the deepest point. Along the brinks and in the water there was grass and it was mainly amongst the flooded grass he caught the N. fuscotaeniatus.


Seegers didn't measure any water parameters in the pond, but Watters, Wildekamp & Cooper did so. The following measurements were noted:

pH 6.50
TDS(ppm) 80
S (mikroSiemens) 160
25C / 78F

So the water was rather soft, but as it often is the case with Nothobranchius species after a few generations, they aren't very particular about the hardness and my fish thrive just fine at 15 dH and pH at 7.5


Keeping and breeding them.

I have always kept my fish in tap water with the water values listed above and it has never caused any problems. It has never been necessary to add salt to the water either as neither fry nor adults seems to be susceptible to Oodenium (velvet). N. fuscotaeniatus isn't one of the most productive species, but if they are fed and kept well they do lay a reasonable amount of eggs. When it comes to temperature they are very flexible and thrive at anything between 20C and 29C (68F to 84F). In the warmest summer months I have even kept them outdoors in large tubs were the temperature variegated from 15C (59F) at night to 27C (81F) on the warmest days. It is noteworthy that individuals that have been outside for 3 months seem to be far greener than the ones that have been indoors in the fish tanks.

The breeding isn't in any significant way different from the majority of the species in the genera. A pair or a trio are kept in a 12 liter tank with a layer of washed out peat. In this the fish lay their eggs. You can also choose to put the peat in a container and thereby reduce the amount of peat used and therefore get a higher concentration of eggs. After about 14 days the peat is removed and excess water is carefully squeezed out. After that you should be able to see the 1.3 mm large eggs, which are clear as glass when you pick through the peat with your fingers. Let the peat dry a bit for around 24 hours before it is all placed in an airtight plastic bag marked with species name, code and date. The bag is then kept at a dark place at a temperature between 21 and 24 degree Celsius (70F to 75F) At this temperature the eggs will be ready to hatch in about three months.

The fry will from the start be able to feed on newly hatched brine shrimps, but they do grow rather slow and will not be sexually mature until they are 10 to 12 weeks old. It is a good idea to separate the males from the females as soon as they can be told apart while they are growing up, or the males will be too dominant towards the females. With species from the Nothobranchius genera it is normally quite easy to sex the young: those that get colures are males. How ever, as the female N. fuscotaeniatus has both the black stripes as well as the blue/green sheen on their bodies, they are easily mistaken for young males. I have more than once been convinced that I had a spawn of 100% males only, but it always turned out that I was mistaken. It is important to take notice of the edges of the fins. Only the males get black edges on their fins so that is the best and safest to look for when sexing the fish. The spawns have usually turned out to have a small over representation of females, something like 60% females to 40% males.

A different Nothobranchius:

I wrote in the beginning of this article that N. fuscotaeniatus is one of my favorites and I better tell you why that is. First of all it has a special ability to punish you for poor treatment. If you have a pair or a trio and you start to skip a water change or two, then the fish will soon stop laying eggs or in some other way show that they aren't thriving. It is also incredible beautiful with its black stripes on the blue and green background, just as it has a special body shape that makes it easy to spot from a distance, all adds to its special charm. A grown male that really turns on his colors and flare with fins and gills to impress a female or to scare off another male is a marvelous sight that one should allow one to see.

References:

Aqualog - Killifishes of the World - Old World Killis II
Marc Bellmanns - http://users.pandora.be/marc.bellemans/Fuscotaeniatus_E.htm
Finn Larsen - "Tanzania 1998" "Killi-News" no. 407 August 1999 and in "JAKA" January/February - Vol. 33, No. 1, 2000. Link: http://home20.inet.tele.dk/fcl/tan98/tan98text.htm