THE NOTHOBRANCHIUS SITE

Syntypes from Pfeffer (1896):

"4 Stücke von Longo-Bay (Emin-Stuhlmann). Ausserdem Seychellen (Günther)."

[4 specimens from Longo-Bay (Emin-Stuhlman). Furthermore, from Seychellen (Günther) [erroneously for Zanzibar]​

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Types from Ahl (1935):

"3 Exemplaren von 46 bis 53 mm Totallänge, Longo Bay, Emin & Stuhlmann leg."

[3 specimens of 46-53 mm TL, Longo Bay]

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Syntypes from Wildekamp (1981):

4 females from present-day Ilongo.

Lectotype from Costa (2017):

BMNH 2016.12.2.1 [ex BMNH 1865.3.18.98-99], lectotype; Tanzania: Zanzibar, Playfair.

BMNH 1865.3.18.98-99 (4), ZMB 12849 (3)

​Nothobranchius melanospilus is distinguished from all other species of the genus by the following combination of characters: in males, a red caudal fin with narrow black margins at the upper and lower corners; a narrow white margin to the dorsal and anal fin; a silver iris. Females are readily distinguished from all other species of the genus by having irregularly dispersed black spots on the flanks and on the basal half of the unpaired fins (Wildekamp et al., 2009).

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Distinguished from all congeners by the combination of the following character states: caudal fin red with black posterior margin in males; posterior portion of flank and unpaired fins with black spots in females; pre-dorsal length in males 62.4–65.1% SL; 3 + 12–14; 5 + 15–16 gill-rakers on first branchial  arch; 29–31 scales in longitudinal series; 16–18 series of scales around caudal peduncle; two longitudinal rows of scales between anterior supraorbital series of neuromasts; anterior supraorbital series of neuromasts arranged continuously, with four well-developed neuromasts; four neuromasts in posterior supraorbital series; 29–31 caudal-fin rays; 30–31 vertebrae; second proximal radial of dorsal fin between neural spines of 13th and 15th vertebrae (Costa, 2017).

Subgenus: Adiniops

Species group: N. melanospilus group

Fundulus melanospilus was established as a species by Pfeffer in 1896 after 4 females specimen from Longo-Bay, present Ilongo in Tanzania, whereas males from the same location were identified in the same publication as Fundulus guentheri. Furthermore, Pfeffer (1896) also mentioned specimens from the Seychelles. This latter locality is clearly misidentified for Zanzibar (Wildekamp, 1981; Costa, 2012). Ahl (1935) restricted the type locality of the species to Longo-Bay, and the remaining specimens mentioned by Pfeffer (1896) originating from the Seychelles are described in the same work by Ahl (1935) as N. seychellensis. Bailey (1969) synonymized with N. guentheri and two species were regarded as synonyms until Wildekamp (1981) restored the validity of N. melanospilus, with the type locality of Ilongo, and restricted the distribution of N. guentheri to Zanzibar.

Nothobranchius emini Ahl, 1935 Ikongoro, eastern Tanzania, and N. seychellensis Ahl, 1935 from Zanzibar (erroneously Seychelles islands) are regarded as synonyms (Wildekamp 1981, 2004).

Populations found since in south-eastern Tanzania and north-eastern Mozambique were, from 1985, referred to as N. aff. melanospilus, based on some similarities in male colour pattern, until these populations were described as N. makondorum by Wildekamp et al. in 2009.  

Populations found in the Kilombero drainage in 1995 were also referred to as N. aff. melanospilus, based on some general similarities; however, there were also some important differences and that species was described as N. lucius by Wildekamp et al. in 2009, including populations from the Mbezi and lower Rufiji drainages, and also from Mafia Island. These latter populations occurring in Mafia Island were separated from the populations on the coastal mainland and described as N. insularis by Costa in 2017.

Costa (2017) redescribed N. melanospilus, and designated lectotype from the specimens originating from Zanzibar.

Based on morphological analyses and minor colour pattern differences, Costa (2019) separated two cryptic species from peripheral parts of the range of N. melanospilus.

Populations found in the Ramisi drainage in southern Kenya, following their discovery in 1974, were referred to N. melanospilus based on some similarities in colour pattern of both sexes, until Costa (2019) described specimens from one location in Ramisi drainage in southern Kenya as N. kwalensis.

Populations found in the upper Wami drainage, including the area around Ilonga, which locality was regarded by Ahl (1935) and by Wildekamp (1981, 2004) as the type locality of N. melanospilus, were described as N. prognathus.

Nothobranchius emini  Ahl, 1935

    Type locality: Ikongoro, eastern Tanzania.

Nothobranchius seychellensis  Ahl, 1935

    Type locality: Zanzibar (erroneously Seychelles islands)

Longo Bay, furthermore Seychelles (Pfeffer, 1896; Ahl, 1935).

Present-day Ilongo, eastern Tanzania, approx. 06°47' S, 37°01' E (Wildekamp, 1981).

Zanzibar (Costa, 2017).

This species is endemic to seasonal freshwater habitats in coastal Tanzania. It is known from temporary pools and marshes on the floodplains of the lower Pangani, lower Wami, Ruvu, Mbezi, Ruhoi, Rufiji, Matandu and Mbwemkuru rivers in coastal Tanzania, as well as in the coastal Unguja Island of the Zanzibar archipelago in eastern Tanzania.

Coastal East Africa (564)

1–205 m

Personal observation at collecting sites (38 locations):

Water temperature: 24.6–33.8 °C (average: 29.2)

pH: 6.50–8.48 (average: 7.62)

TDS:  12–1146 ppm (average: 183)

Conductivity: 24–2292 µS (average: 365)

N. janpapi - 29%

N. eggersi - 16%

N. annectens - 10%

N. ocellatus - 10%

N. luekei - 3%

N. rubripinnis - 3%

N. albimarginatus - 2%

N. foerschi - 2%

N. lourensi - 2%

N. lucius - 2%

N. flammicomantis - 1%

N. fuscotaeniatus - 1%

N. guentheri - 1%

N. palmqvisti - 1%

This species has a semi-annual or annual life cycle, depending on the particular part of the range; those from the southern parts of the distribution range are annual, whereas the central and northern near-coastal habitats can be semi-annual.

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

Maximum size reported: 57.4 mm SL (MRAC 98-008-P-0001, male)

Diploid chromosome number 2n = 38 (Post, 1964; Scheel, 1981; Scheel, 1990 [Ruvu and Rufiji]; Wildekamp et al., 2009); NF = 50, karyotype structure 4m+8sm+26st/a (Krysanov & Demidova, 2018).

Karyotype structure unique in the genus.

The specific name is formed from melas (in Greek for black) and spilos (in Greek for spots), in reference to the black spotted colour pattern of females.

Least Concern (Nagy & Watters, 2021);

Previous assessments: Least Concern (Nagy & Watters, 2019);

Least Concern (IUCN Red List 2006)

​    Pfeffer, G. 1896. Die Fische Ost-Afrikas. In: K. Möbius (ed.), Deutsch-Ost-Afrika. Teil 3. Die Thierwelt Ost-Afrikas. Reimer, Berlin, 72 pp. [taxonomy as Fundulus melanospilus]

    Wildekamp, R. H., K. M. Shidlovskiy & B. R. Watters. 2009. Systematics of the Nothobranchius melanospilus species group (Cyprinodontiformes: Nothobranchiidae) with description of two new species from Tanzania and Mozambique. Ichthyological Exploration of Freshwaters, 20 (3): 237–254. [morphology, genetics, systematics]

    Nagy, B. & A. Horváth Kis. 2010. Variation in habitat characteristics and the occurrence of Nothobranchius species in seasonal biotopes of Tanzania. Journal of the American Killifish Association, 43 (5): 130–144. [ecology]

    Nagy, B. 2010. A la recherche de killis sur l’île de Pemba et dans la partie côtière de la Tanzanie. Killi Revue, Killi Club de France, 2010 (5): 3–11. [collecting]

    Nagy, B. 2015. Life history and reproduction of Nothobranchius fishes. Journal of the American Killifish Association, 47 (4-6): 182–192. [ecology]

    Costa, W. J. E. M. 2017. Taxonomic revision of the seasonal killifish genus Nothobranchius from Zanzibar, East Africa (Cyprinodontoidei: Aplocheilidae). Journal of Natural History, 51, 1609–1624.

    Costa, W. J. E. M. 2019. Two new species of seasonal killifishes of the Nothobranchius melanospilus species complex from the East Africa biodiversity hotspot (Cyprinodontiformes: Aplocheilidae). Vertebrate Zoology, 69 (1): 73–82. [systematics]

    Bartáková, V., B. Nagy, M. Polačik, R. Blažek, H. Lamtane & M. Reichard. 2020. Genetic diversity of a widespread annual killifish from coastal Tanzania. BMC Evolutionary Biology, 20: 1, 13 pp. [genetics]

    Nagy, B. & B. R. Watters. 2021. Nothobranchius melanospilus. The IUCN Red List of Threatened Species: e.T164386040A164386078. [conservation]