Aphyosemion thysi Radda & Huber 1978

A.thysi RPC 9 circulating in the US around 1980. Photo: Courtesy of Lennie MacKowiak

Meaning of Name

After Prof. Dr. Ir. Dirk Thys van den Audenaerde, a Belgian ichthyologist & director of the Musée Royale de l'Afrique Centrale, Tervuren.

First Description

Radda A.C. & Huber J.H. 1978.

Die Rivulinen des südlichen Kongo (Brazzaville) I, Beschreibung von vier neuen Arten der Gattung Aphyosemion Myers.

Aquaria 25: p 173-175, figure 1-2.


5 cm


D = 11-12, A = 14-15, D/A = +7-8, ll = 29-30 (+1-2) (Radda & Huber 1978)


n = 14, A = 26 (Scheel 1981)




thysi (given as ogoense in 'Killies of the World' Vol I (Wildekamp) although this was noted as the opinion of Radda & Huber. Wildekamp considered them to be closely related to A.schluppi. In view of the similarity of finnage & general shape I would agree with this. Also, both species are found in close proximity.



  • Gnimi - Southern Congo
  • Komono ( PK 30 )
  • Maniemo - Loumbanda (Loumbamba ?) River, southern Congo)
  • M'bila
  • Mossendjo
  • N'Gala
  • Titi
  • CMBB89 / 12
  • CMBB89 / 14
  • CMBB89 / 16
  • COFE 11 / 13
  • GHP 82 / 12 - North of Mossendjo
  • JH 158 - 7 km west of Mossendjo
  • JH 162 - 25 km south east of Mossendjo
  • JH 215 - 17 km south of Mougoundou
  • RPC 6
  • RPC 7
  • RPC 9 (Red)
  • RPC 20 (Green)
  • RPC 22 (Blue)

Loumbamba River. Photo courtesy of Ed Pürzl

A.thysi RPC 6 circulating in the US around 1980. Photo: Courtesy of Lennie MacKowiak

A.thysi. Photo courtesy of Ed Pürzl

Photo courtesy of Maurice Chauche & the KCF website.



CMBB89 / 12
CMBB89 / 14 -
See photo BKA Killi-News No. 295, April 1990.
CMBB89 / 16
- Collected by Buytaert & Wachters at 1030 hrs on the 14th July, 1978 in a stream 500 metres from Ngala on the Titi - Mossendjo road in the province of Niari in the Louesse Basin of southern Congo (Brazzaville). Air temperature 24°C, water temperature 18°C, pH 6. Sympatric sp. Ctenopoma nanum.
- Collected at 1430 hrs on the 14th July, 1978 in the forest river Loumbamba, 3 km past Ngala near the village of Maniembo. Air temperature 24°C, water temperature 18°C, pH 6·5. Sympatric sp. A.coeleste.
- Collected on the 15th July at 0830 hrs in Birihele in the upper section of the Obouesse River 1km beyond N'zibau'ziba on the Mossendjo - Moungoundou road. Imported by BKA Species Import Committee June/July 1981. Sympatric sp. A.coeleste.
RPC 20 - Collected on the road between Mossendjo - Komono. Sympatric sp. A.coeleste, A.ogoense (form), Amphilius pulcher, Barbus sp. (3).
RPC 22 - Collected on the 20th July at 1700 hrs in a stream in dense forest 13km northeast of Komono on the Nbila road in the upper basin of Lelali of the Louesse River. Air temperature 21·5°C, water temperature 20°C, pH 6·5. Sympatric sp. A.pyrophore.
JH 158 - Collected by Dr.J.H.Huber in July/August 1978 in a small forest stream 2-3 metres wide, 40-90 cm deep, 7km west of Mossendjo on the station road in a tributary of the Itsibou. The biotope had a clay bottom & had cloudy water. The fish were found near the waters edge protected by overhanging steep grassy banks. Air temperature at 1000 hrs 19·3°C, water temperature 19·4°C, pH 6·5, DH 4·5. Sympatric sp. Mormyre, Barbus camptacanthus.
JH 162 - Collected on the road from Mossendjo to Komono about 25km east of Mossendjo, 2km before crossing the Louesse River. Found in a fast flowing stream 3 metres wide, 20 cm deep. The biotope had a large amount of vegetation. Sympatric sp. A.coeleste

Type Locality

500 m from Ngala, on the Titi - Mossendjo road, Niari Province, Louessé River drainage system, southern Congo.


The area of Mossendjo - Komono in the Louessé - Niari River drainage system.


Hilly rainforest & tree grassland brooks/small streams. Sympatric sp. include A.schluppi, A.wachtersi & A.buytaerti.

Distinguishing Characteristics Anal & dorsal fins are pointed much the same as A.schluppi. A.thysi is not a very colourful species, lacking bright colouration. The upper caudal fin can have a larger extension than the lower.
Colour/Pattern Variability Medium

Discovered by Buytaert & Wachters on the 14th July 1978 at 1030 hrs at collection point RPC 6. Also collected from points RPC 7, 9, 20 & 22.
Huber collected them in July/August 1978 at collection points JH 158 & JH 162.

Imported to the UK & distributed by BKA Species Import Committee July/August 1979. This location was RPC 22.

Breeding Notes

Regarded as a more difficult species. I bred the RPC 9 population in the early 1980's & raised on about 3 pairs. Most eggs were laid in top mops but the odd one was found on bottom mops but were not prolific. At the time I used hard water DH 10, pH 7-8 temperature 73-75°F. I would use rainwater for future attempts which would probably give better results. Water incubation is around 14 days but I have seen reports which suggest they can hatch in 10 days.. Newly hatched fry are a good size but I used infusoria which was always in the tank for the first week graduating onto micro worm & newly hatched brine shrimp. Also, they are sensitive to velvet so the tank must be kept clean at all times. Sexual maturity is slow in coming at around 8 months.
I found they were not very prolific in this harder water with about 2 eggs per day being average. Gaps of 2-3 days where no eggs were found was also usual. When I moved the pair into a peat based tank (gradual aclimatisation) egg yield increased to 6-7 per day. I would recommend this setup with this sp. as the males show better colouration.

Diameter of Egg Fairly large.

The male I received seemed quite thin & required 3 months of heavy feeding on white worm & other live foods to get some body on him. Many photos I have seen of males also show a thin body. I'm not sure why this should be.