THE NOTHOBRANCHIUS SITE

SMF 12273, holotype, male, 31.0 mm TL; Tanzania: ditches on Mafia Island (approx. 07°58' S, 39°44.5' E); E. Korthaus, 1973.

SMF 12274 (4)

Nothobranchius korthausae is distinguished from the congeners, except N. ruudwildekampi, by the combination of transverse bars in the caudal fin, a white distal margin to dorsal and anal fins, and a blue blotch on the distal portion of the pectoral fin in males. Nothobranchius korthausae is distinguished from N. ruudwildekampi by the possession of subdistal black bars on the unpaired fins in males, a narrow yellow to white distal margin on the caudal fin in males, 10-14 red-brown bars on the anal fin in males, two colour morphs in males and the absence of minute horizontally elongated dark grey spots on the posterior portion of the pectoral fin in males (after Costa, 2009).

Subgenus: Adiniops

Species group: N. guentheri group

Nothobranchius korthausae was established as a species by Meinken in 1973, and that status has since been accepted by all authors. The species was known to occur only in Mafia Island until 2000, when several populations showing close similarities in male colouration to N. korthausae were found in coastal mainland. These latter populations were described by Costa (2009) as N. ruudwildekampi, restricting the distribution of N. korthausae again to the originally defined Mafia Island. 

"Gräben auf der Insel Mafia, Tansania."

Tanzania: ditches on Mafia Island (approx. 07°58' S, 39°44.5' E)

This species is endemic to seasonal freshwater habitats in coastal Tanzania. It is known from temporary pools and swamps in Mafia Island, eastern Tanzania.

Coastal East Africa (564)

6–26 m

Personal observation at collecting sites:

Water temperature: 28.7–33.1 °C

pH: 5.79–7.50

TDS:  51–93 ppm

Conductivity: 102–186 µS

N. insularis - 5%

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: 31.0 mm TL (SMF 12273, holotype, male), 29.9 mm SL (Costa, 2009)

Diploid chromosome number 2n = 36 (Scheel, 1981; Scheel, 1990); NF = 40, karyotype structure 4m+32st/a (Krysanov & Demidova, 2018).

Karyotype structure shared with some members of the subgenus Adiniops.

The specific name is given in honor of Edith Korthaus, editor of  the German magazine 'Das Aquarium', and "she made the preserved material available for determination" (Meinken, 1973).

Endangered B1ab(iii)+2ab(iii) (Nagy, B. & B. Watters, 2019);

Previous assessment: Vulnerable D2 (IUCN Red List 2006)

    Meinken, H. 1973. Nothobranchius korthausae spec. nov., eine hübsche Cyprinodon­tiden von der Insel Mafia (Ost Afrika). Das Aquarium, 7 (51): 351–355. [taxonomy as Nothobranchius korthausae] 

    Nagy, B. 2008. Mafia Island - Notes on the distribution of Nothobranchius and my recent collections. Journal of the American Killifish Association, 41 (5): 129–144. [collecting, ecology]

    Watters, B. R., B. Nagy, P. D. W. van der Merwe, F. P. D. Cotterill & D. U. Bellstedt. 2019. Review of the Nothobranchius taeniopygus species group from central and western Tanzania with descriptions of five new species and redescription of Nothobranchius taeniopygus (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, IEF-1110, pp. 1–41. [phylogeny]

    Nagy, B. & B. R. Watters. 2019. Nothobranchius korthausae. The IUCN Red List of Threatened Species 2019: e.T60308A47182634. [conservation]