THE NOTHOBRANCHIUS SITE

SMF 4356, holotype, male, 22.0 mm SL; Tanzania: Soga near Dar es Salaam (06°43' S, 38°49' E); imported by Tropicarium in Frankfurt, 14 Mar 1957.

ZMH 344 (6), ZMH 972 (2), ZSM 15433 (1), ZSM 18763-70 (8)

​Die sonst sehr ähnlichen Männchen von N. palmqvisti haben gegenüber N. foerschi in den gesamten Flächen der Dorsale, Anale und den Ventralen unregelmäßig verlaufende rote Querlinien (after Wildekamp & Berkenkamp, 1979).

[Males of the the very similar N. palmqvisti have, compared to N. foerschi, irregular red striped pattern in the entire surface of the dorsal, anal and pelvic fins.]

Males have a green-blue body, with red-brown scale margins creating a uniform reticulated pattern on the body; the caudal peduncle is deep red; the anal fin is uniform yellow. The female has a grey reticulation on the dorsal and posteroventral parts of the flanks.

Subgenus: Adiniops

Species group: N. guentheri group

​First population of this species was imported in 1957 and was referred to as N. species Dar es Salaam or erroneously as N. palmqvisti Dar es Salaam. Nothobranchius foerschi was established as a species by Wildekamp and Berkenkamp in 1979, and that status has since been accepted by all authors.

"Tansania: Soga bei Daressalam."

[Tanzania: Soga near Dar es Salaam (approx. 06°43' S, 38°49' E).]

This species is endemic to freshwater habitats in coastal Tanzania. It is known from temporary pools and swamps in the lower Ruvu River drainage, eastern Tanzania.

Coastal East Africa (564)

2–205 m

Personal observation at collecting site:

Water temperature:  27.7 °C

pH: 7.02

TDS: 1130 ppm

Conductivity: 2260 µS

N. melanospilus - 80%

N. janpapi - 70%

N. annectens - 20%

N. ocellatus - 10%

This species has a semi-annual life cycle.

Embryonic development under captive conditions in peat moss is about two to three months at room temperature.

Maximum size reported: 35.5 mm SL (ZSM 18763–70, paratypes)

Diploid chromosome number 2n = 34 (Scheel, 1981; Ewulonu et al., 1985; Scheel, 1990), NF = 46, karyotype structure 10m+2sm+22st/a (Krysanov & Demidova, 2018).

Karyotype structure unique in the genus.

The specific name is given in honour of Dr. Walter Foersch, German aquarist and the first to breed this species.

Vulnerable B1ab(iii) (Nagy & Watters, 2019);

Previous assessment: Vulnerable D2 (Hanssens & Snoeks, 2006)

​    Wildekamp, R. H. & H. O. Berkenkamp. 1979. Nothobranchius foerschi spec. nov. ein aquaristisch bekannter, jedoch wissenschaftlich neuer Prachtgrundkärpfling aus Tansania/Ost Afrika (Pisces, Cyprinodontidae). Deutsche Killifisch Gemeinschaft Journal, 11 (11): 145–157. [taxonomy as Nothobranchius foerschi]

    Nagy, B. & B. R. Watters. 2019. Nothobranchius foerschi. The IUCN Red List of Threatened Species: e.T60348A47184248. [conservation]

    Watters, B. R., B. Nagy, P. D. W. van der Merwe, F. P. D. Cotterill & D. U. Bellstedt. 2020. Redescription of the seasonal killifish species Nothobranchius ocellatus and description of a related new species Nothobranchius matanduensis, from eastern Tanzania (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, IEF-1149, pp. 1–28. [phylogeny]