Aphyosemion obscurum (Ahl 1924)
A.obscurum,
wild male collected 20 km west of Yaounde, Cameroon.
Photo Courtesy of Ed Pürzl
Aphyosemion obscurum (Ahl 1924)
A.obscurum,
wild male collected 20 km west of Yaounde, Cameroon.
Photo Courtesy of Ed Pürzl
| Meaning of Name |
Obscure (dark). Refers to the dark colouring on the body of the type specimen. |
| First Description |
Ahl E. 1924. Zur Systematik der altweltlichen Zahnkarpfen der Unterfamilie Fundulinae. Zoologischer Anzeiger 60 (1-2): 55. |
| Size |
5 cm. |
| Meristics |
D = 12, A = 16, D/A = +7, ll = 29 (Ahl in the
original description) |
| Karyotype |
17 (22) (Scheel). |
| Sub-Genus |
Mesoaphyosemion |
| Group |
A.cameronense |
| Synonyms |
|
Populations
|
Bikok - Amiet collected here & reported the location in his 1987 book. No exact information is available on the collection point but the village is 24kms as the crow flies from Yaoundé to Bikok. This is probably a frontier area with A.cameronense. Binguéla II - Nothing is known about who collected this population originally or where they collected. They were at least maintained in Germany in the mid 1980's but no longer exist in aquaria from this date. CCMP 85/15 (Kala) - Chauche, Marsan & Poliak collected these from Kala in 1985. It is thought this code was not distributed in the hobby. C 89/42 - Fished on 26th July 1989 by Wolfgang Eberl, Oliver Legros & Bas Vlijm. Near Matomb II 7·8kms northeast of the turning off the Axe Lourd to Matomb. Water temperature 23°C, stream was 40 cm deep & 1·5 metres wide, fast flowing with a pH of 6·5 & a 0 hardness dGH. Also colected were barbs & Mormyridae sp. C 89/43 - Near Matomb III. Collectors as above. EMS 90/13 - Collected by Wolfgang Eberl, Francisco Malumbres & Jorge San Juàn De Torres on 21st August 1990 at 12 noon. Near the outskirts of Matomb. From the Axe Lourd road a few kms on the Route Ancienne to the first buildings of Matomb. Villagers showed them a small stream containing A.obscurum. This stream was 10 cms deep & 40 cm wide. Water flow was slow & was clear & brownish. Water temperature was 23°C. K9 - Collected by Heinemann, Lenz, Berger, Wardega & Holler end of 1978 beginning 1979. The K refers to Kamerun (German spelling). A stream on the Route Ancienne from Yaoundé in the direction of Eséka (& Edéa). Location is recorded as being 46kms west of Yaoundé between Ngoulémakong & Matomb. Barbs & catfish also collected here. Kala - Amiet collected here probably mid 1970's. No live fish were sent into the hobby. Possibly Amiet's work was used as a reference in the CCMP 85 collection trip by Chauche, Marsan & Poliak. KEK 98 / 23 - Collected
January 11th 1998 by Wolfgang Eberl, Andreas Kliesch & Uwe Kaempf.
Situated at the village of Mandoumba II on the Axe Lourd road, 40kms
west of Yaounde. The small stream in the rainforest was called the
Lebibi which is about 400 metres down a trail. It was artificially
dammed up but a few metres downstream flows into the rainforest untouched.
It is a very dark place with dense vegetation. The stream is 30-50cm
wide & 10-20 cm deep. The muddy base was covered with a thin layer
of leaves. A.obscurum was the
only fish found in this area but was so numerous they collected 15
pairs of varying ages in a short period. Matomb - According to Eberl
(BKA Newsletter No.317) this location had 'beautiful red markings. Ototomo - Amiet mentions this location in his 1987 book. Location is given as 34kms as the crow flies from Yaoundé. Eberl traced this location as being on the Mbankomo to Ngoumou road a few kms from the village of Akono. Not sent back for distribution i the hobby. W. Yaunde, E. Cameroon - Scheel pictures this in his Atlas of Killifish (1990). This was a photo of a fish he had collected probably west of Yaoundé in eastern Cameroon. They may have been bred & distributed by Scheel but they do not exist in the hobby now. 7kms East of Matomb - Mentioned in Radda & Pürzl's book of 1976. Thought to be on the road from Yaoundé to Edéa. |
| Type Locality |
Yaoundé. Referred to as 'Jaunde, Kamerun' which was a German colony until the end of WWI. Considered by Eberl to be within the present city of Yaoundé which was considerably smaller in the 1920's than today. |
| Distribution |
Small area southwest of Yaounde, Cameroon along
the Edéa to Yaoundé road. To the east it is replaced by
A.raddai. |
| Habitat |
Shallow swamp areas in streams in rainforest of the Akono & Mefou drainages. They are found in dark areas. Scheel reported the location 18 miles east of Yaounde as being a 'dirty, muddy, almost stagnant brook, with many red deposits, probably iron oxides'. |
| Distinguishing Characteristics | A
species with similarities (red spots forming rows or lines through the
body) to A.striatum but both species
are sufficiently seperated to belong to two distinct species. This species has been confused with A.raddai. In A.raddai the anal fin has 2 horizontal red lines in the centre of the anal fin. A.obscurum has a yellow, white or blue outer margin with a red submarginal band. The rest of this fin has red spots. |
| Colour/Pattern Variability | |
| History |
Scheel in ROTOW 1 considered that this species may have been imported into Germany in 1913. Ahl described this species in 1924 from a single
specimen 28 mm long collected at Yaounde, eastern Cameroon by G.Zenker.
The location was referred to as 'Jaunde Kamerun'. Holly, in 1930, examined
the holotype & changed some of Ahl's data. Holly in 1930 examined the type fish & made some adjustments to the measurements. Again, Scheel considered it possible this species may have been introduced into the USA in 1933 according to the fish photographed in Innes' book of 1935. Scheel collected them in 1966 from many localities in eastern Cameroon. He brought back live fish from a point 18 miles east of Yaounde towards Edea & established an aquarium population. In 1974 Scheel used the term 'subphenotype' which resulted in the fish being called Aphyosemion cameronense obscurum. Imported early 1979 by Heineman & Lenz. Berkenkamp referred to this collection as Aphyosemion obscurum. Early 1980's saw some imports into Europe but these were not successfully distributed. Amiet in his 1987 book reports collecting this fish & regarded them to be called a seperate species - Aphyosemion obscurum. Seegers in 1988 reported that the type specimen was a young male. In 1989 Bas Vlum imported 2 forms from the area around Matomb. These did not get distributed in the hobby. In 1990 Eberl et al collected them & distributed the species in the hobby. History of the synonym Panchax bellicauda Ahl 1924 Ahl described this sp. from 9 specimens collected from the Upper Lobo River area near Sangmelima, eastern Cameroon. In 1930 Holly considered this sp. to represent a synonym of cameronense. Scheel collected in this area in 1966 & found A.exiguum, E.sangmelinensis & bellicauda, which he considered resembled cameronense in most traits. He later placed this bellicauda material in obscurum. History of the synonym Panchax preussi Ahl 1924 Ahl described the species from a single
specimen collected at Yaunde, Cameroon. He considered the species to
be closest to A.cameronense which
was fairly accurate. History of the synonym Panchax carnapi Ahl 1924 Ahl based his description of carnapi
on a single specimen collected at Yaunde, East Cameroon. In 1929 Pellegrin
reported them from Banyo, Bamkin, Foumban & Yoko in East Cameroon.
These localities are in savannah areas & Scheel in ROTOW
1 p. 148 considered they might be A.bualanum. History of the synonym Panchax normani Ahl 1928 Ahl described this species in 1928 from a single specimen collected at Yaounde, eastern Cameroon by Zenker. |
| Breeding Notes |
Regarded as a difficult fish to breed, probably the hardest in the A.cameronense group. Natural breeding methods using a well planted tank seem to prove beneficial. Scheel considered them to be susceptible to attack from Mycobacteria & suggested maintaining them in 'clean, hard & alkaline water' & using 'slightly acid water' for breeding. Uwe Kaempf put a breeding report in BKA newsletter
No.400, January 1999. Water was 22°C, pH 7·5 & GH 10.
A thin layer of sand was on the base of the tank. Eggs were found on
mops & put on humid peat. After 2 weeks this was wet with slightly
cooler water & all eggs hatched. Water temperature fluctuated between
18 - 22°C in later spawnings but eggs were found daily up to 20
at one time in a single day. As the fish got older egg development was
noted to be taking longer - 18 days. |
| Diameter of Egg | 1.3 mm |
| Remarks |
Young fish are sensitive to build ups of waste products in the water. Sudden changes of water are also harmful. Small, regular water changes are considered the best way to maintain them. |
References
Faszination Killifische: Die Aphyosemion cameronense Gruppe. Dadaniak, Lütje & Eberl