THE NOTHOBRANCHIUS SITE

MRAC 2016-027-P-0001, holotype, male, 33.0 mm SL; DR Congo: Lake Mweru basin: ephemeral swamps of the Katate system, about 9.5 km northwest of Kilwa village, 09°12'33" S, 28°17'01" E; B. Nagy, A. Chocha Manda & G. Petneházy, 13 Apr 2016 [field code: CD 16-13].

MRAC 2016-027-P-0002-3 (2), MRAC 2016-027-P-0029-31 (3), MRAC 2016-027-P-0004-10 (7)

Nothobranchius ditte is distinguished from all other species of the N. brieni species group, with the exception of N. milvertzi, by having anal and caudal fins with slender orange subdistal band and broad dark brown distal band. Further, N. ditte is distinguished from N. milvertzi by having caudal fin yellow to light blue, with red-brown spots proximally and medially (vs. plain red); and smaller caudal peduncle length (130–140 % of its depth vs. 141–159).

Subgenus: Zononothobranchius

Species group: N. brieni group

Nothobranchius ditte was established as a species by Nagy in 2018.

DR Congo: Lake Mweru basin: ephemeral swamps of the Katate system, about 9.5 km northwest of Kilwa village, 09°12'33" S, 28°17'01" E.

This species is endemic to freshwater habitats in south-eastern Democratic Republic of the Congo. It is known from seasonal pools and swamps of river drainages in the south-western part of the Lake Mweru basin.

Bangweulu–Mweru (544)

933–973 m

Water parameters at type locality (Nagy, 2018):

Water temperature: 24.6 °C

pH: 7.31

Total dissolved solids: 58 ppm

None

The species has an annual life cycle.

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

Maximum size reported: 42.4 mm SL (MRAC 2016-027-P-0029, paratype, male)

Diploid chromosome number 2n = 39 for males and 2n = 40 for females (Simanovsky et al., 2018); NF = 64/64, karyotype structure 13m+12sm+14st/a for males and 12m+12sm+16st/a for females (Krysanov & Demidova, 2018).

Diploid chromosome number and karyotype structure unique in the genus.

The specific name is given in honour after the wife of the author, Edit Csikós, after her nickname. A noun in the nominative singular standing in apposition to the generic name.

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

Previously recommended as Vulnerable (B1bii) in Nagy, 2018.

​     Nagy, B. 2017. Collecting Killies in the Democratic Republic of Congo. Tropical Fish Hobbyist, #724, May/June 2017, 65 (5): 46–52. [collecting as Nothobranchius sp.]

    Nagy, B. 2018. Nothobranchius ditte, a new species of annual killifish from the Lake Mweru basin in the Democratic Republic of the Congo (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, 28 (2): 115–134. [taxonomy as Nothobranchius ditte, distribution, ecology]

    Nagy, B. & B. R. Watters. 2019. Nothobranchius ditte. The IUCN Red List of Threatened Species: e.T131470719A131470723. [conservation]

    Nagy, B. 2020. Lands of the unknown Nothobranchius. Practical Fishkeeping, 2020 (12): 24–31. [collecting]