Referring to the Niger Delta.

Radda A.C. 1976.
Neubeschreibung von Aphyosemion amieti nov.sp. aus Kamerun und Aphyosemion deltaense nov.spec. aus Nigeria.
Aquaria (St.Gallen 23: 51-60, 4 figures, 2 tabs.

10 cm.

• D = 16, A = 18, D/A = 0, ll = 33 (Huber - Killidata online).

Gularopanchax

• Aphyosemion NSC - 7 Ingersoll 1975
• Aphyosemion 'Liverpool' or 'Manchester' fallax (a BKA working name)
• Aphyosemion 'Deltafish' (a working name suggested by Radda 1976)
• Aphyosemion deltaense Radda 1976
• Fundulopanchax gulare Parenti 1981
• Fundulopanchax deltaensis Lazara 1984
• Aphyosemion (Gularopanchax) deltaense Huber 1994
• Giant filamentosum

Populations

• Bolu-Angiama OJ0 3/9
• Koloware ( CI 05 )
• Odieke, Orashi River
• Rumuokwuta, near Port Harcourt
• Warri (deltaense form)
• CI 05 (Import into the USA)
• TAAG 2003 / 3

• Odieke - Orashi River, southern Nigeria. Collected by Uyi & Otufu in 1991.
• Rumuokwuta - Near Port Harcourt. Collected by Powell in 1980.

Approx. 200 yards south of the Sapele - Benin to Warri road, western Niger Delta.

Restricted to the western Niger Delta area.

Coastal lowlands. They inhabit temporary pools with stagnant water over dark substrate of decaying leaves & bottom mulm. Water depth has been recorded at 30 cm, water temperature 20-30°C. Known to eat ants & other insect sp.

Only really confused with Fp.gularis. This sp. has a more randomly spread distribution of red spots on the sides whereas deltaensis has a more solid line sometimes shown as a row of red spots.
Also, the anal fin in deltaense is clear (usually very pale blue) whereas in gularis a line of red can be seen.
A recent (2003) shipment caused us to look closer at the females, as sjoestedti & deltaensis females arrived in the same bag. Seperating these proved relatively easy as sjoestedti females have feint vertical markings on the rear part of the body with a line of red or dark spots just above the body on the dorsal fin.
deltaensis females by comparison have spots on the body which can form 2 (or more) distinct lines horizontally through the body.

Fp.fallax is another sp. often confused & indeed may be involved with historic descriptions. Easily seperated from fallax - deltaensis is a more chunky looking fish with a more flared caudal fin. Also has a line running horizontally through the body whereas fallax has a series of spots.

Originally found in a commercial import. They are regarded to have been collected in the Sapele - Warri area of Nigeria.
At the turn of the century an import into Germany was thought to contain Fp.deltaensis. These fish were referred to as 'yellow' gulare although they were imported as arnoldi.
They are reported to have arrived in the UK through a schoolboy who, on his return from Nigeria sold them to a local fish wholesaler. This is the origin of the names 'Liverpool & Manchester' fallax. J.Jeremy (BKA) bought some & they were distributed.
Dr. Ingersol gave Dr.A.C.Radda eggs of Fp.deltaensis at the 1974 AKA convention. This sp. was then referred to as A.fallax & NSC 7 in the USA. The name 'Deltafish was reportedly first used by Radda.

It's interesting to look into historic line drawings. Not sure where these drawings (left) were used but most likely Schreitmüllers pair (top) were probably used in his 1933 description Fundulopanchax spurelli (non Boulenger 1913) Schreitmüller 1933. This is considered a synonym of Fp.fallax but note the horizontal line through the centre of the body which is typical of deltaensis & not fallax which carries a series of spots. Also the bottom drawing carries this line. Note also the very flared caudal on both drawings which is typical of deltaensis. Fp.fallax is a 'heavier' looking fin. The bottom drawing was probably used in their description Aphyosemion fallax Arnold & Ahl 1936. I have not seen preserved material but these drawings show 2 areas typical of deltaensis - horizontal line through centre of body & flared rather than 'heavy' caudal fin. Even with 'artistic license' these characters are shown clearly.

Geoff Wood gave a breeding report of deltaense in BKA newsletter No.141, May 1977. He found egg output was quite low when compared to sjoestedti. Most eggs were laid in large clumps of peat fibre but occaisionally a few eggs were found in a floating mop. Collected eggs were stored in damp peat moss for 3 months at about 72°F.
Fry on hatching are quite large & able to take newly hatched brine shrimp. Growth rate was rapid with three quarters to an inch being attained in a little over a month. He recorded that the young fish fed heavily & as a consequense regular water changes were a must. Also, when the fish get to about 1" they start to fight amongst each other causing fatalities. When transferred to larger tanks this eased the problem.
He noted that fish below the age of 5-6 months produce very few fertile eggs.

First signs of sexing I noticed around 2·5 cm with a dark horizontal line gradually becoming darker. This showed males coming through. At this stage these individuals would become decidedly more aggressive.

1·6 mm.

Can be an aggressive sp. & a larger tank is recommended.
This is not a common sp. & not a fish seen in long term breeding projects which is a shame as