THE NOTHOBRANCHIUS SITE

ZMB 4754, lectotype, Mozambique: Quelimane (approx. 17°45' S, 36°50' E); collected by W. C. H. Peters in 1843–44.

BMNH 1861.5.2.88-89 (2); FMNH 54289 [CM 2920] (1); ZMB 6873 (5), 21481 (10), 31526 [ex ZMB 4754] (2)

Nothobranchius orthonotus is characterized by males having a grey body with red-brown spots on the head and anterior part of trunk and with red-brown scales border on posterior part of the sides; the dorsal and anal fins are olive with a variable density of red to red-brown spots and stripes, and with a narrow white distal band; the caudal fin is red to red-brown, sometimes pale red, with darker red-brown spots proximally. Females are grey-brown, usually with some dark grey spots on the sides and on the unpaired fins.

Subgenus: Nothobranchius s.s.

Species group: N. orthonotus group

Cypronodon orthonotus was established as a species by Peters in 1844, based on specimens collected near Quelimane in Mozambique. Subsequently, Peters (1855) listed the same species under the name Hydrargyra maculata, without any explanation, thus the name became a nomen nudum. Günther (1866) assigned the species into another genus as Fundulus orthonotus. Finally, Peters (1968) assigned the species into a newly erected genus Nothobranchius.

Fundulus kuhntae has been described from Portuguese East Africa, presently Mozambique, by Ahl in 1926. This name is regarded as synonym of N. orthonotus in Wildekamp 2004, which is confirmed by Costa 2018, stating that the exact type locality of N. kuhntae is unknown, and the examination of type materials of N. orthonotus and N. kuhntae did not provide any morphological evidence that they are different species.

Adiniops troemneri was described based on aquarium material from East Africa by Myers in 1926. Later, Myers (1933) recognized it as synonym of N. orthonotus.

Nothobranchius mayeri was described based on specimens from Portuguese East Africa by Ahl in 1935. Scheel 1968 proposed as a probable synonym of N. orthonotus, whereas Seegers (1981) suggested as a probable synonym of N. kuhntae. Wildekamp et al. (1986) suggest synonym of N. orthonotus, whereas Costa (2018) suggest the probability of N. mayeri as a valid species, differing from N. orthonotus by a different dentition, as revealed through examination of type specimens.

Hydrargyra maculata  Peters, 1855

    Type locality: Mossambique (Mozambique)

Fundulus kuhntae  Ahl, 1926

    Type locality: Portugiesisch Ost-Afrika (present Mozambique)

Adiniops troemneri  Myers, 1926

    Type locality: East Africa [aquarium material]

Nothobranchius mayeri  Ahl, 1935

    Type locality: Beira, Portugiesisch Ost-Afrika (present Mozambique)

Mozambique: freshwater swamps in Quilimane [Quelimane] (approx. 17°45' S, 36°50' E)

This species is endemic to seasonal freshwater habitats in southern Malawi, south-eastern Zimbabwe, southern Mozambique and north-eastern South Africa. It is known from seasonal pools and swamps on the floodplains of:  the lower Shire system in southern Malawi; the Montepuez, Luala, lower Zambezi, lower Limpopo, Pungwe, Buzi, Incomati, Guluene, Save and Mazimechopes systems in southern Mozambique; the Pongolo and Mkuze in KwaZulu-Natal, South Africa; headwaters of the Mazimechopes system and the N’tomeni River in north-eastern South Africa; and in the Limpopo and Guluene system in south-eastern Zimbabwe.

Lower Zambezi (561)

Coastal East Africa (564)

Zambezian Lowveld (576)

3–376 m

Water parameters based on Watters (personal data) are as follows: temperature of 23–32°C; pH of 5.8–7.9; conductivity of 40–2020 µS; and typically turbid (Nagy & Watters, 2019).

N. furzeri - 20%

N. pienaari - 17%

N. kadleci - 5%

N. krysanovi - 4%

N. rachovii - 3%

This species has an semi-annual life cycle.

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

Maximum size reported: 62 mm SL (Bruton & Kok, 1980)

Diploid chromosome number 2n = 38 (Post, 1964 [as N. mayeri]; Scheel, 1990 [as N. kuhntae]), NF = 48, karyotype structure 8m+2sm+28st/a (Krysanov & Demidova, 2018).

The specific name is formed from orthos (in Greek for straight) and notos (in Greek for back), in reference to the morphology of dorsal surface in the preserved type specimens.

Least Concern (Nagy & Watters, 2019)

Previous assessments: Least Concern (Bills, Engelbrecht, Kazembe, Marshall & Tweddle, 2010); Least Concern (2007); Vulnerable (2006)

​    Peters, W. C. H. 1844. Mittheilungen von Hrn. Peters, Über einige neue Fische und Amphibien aus Angola und Mozambique. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlichen Preussische Akademie der Wissenschaften zu Berlin aus dem Jahre 1844: 32–37. [taxonomy as Cyprinodon orthonotus]

    Peters, W. C. H. 1855. Uebersicht der in Mossambique beobachteten Fische. Archiv für Naturgeschichte, 21 (1): 269. [taxonomy as Hydrargyra maculata, nomen nudum]

    Peters, W. C. H. 1868. Über eine neue Untergattung der Flederthiere, so wie über neue Gattungen und Arten von Fischen. Monatsberichte der Königlichen Preussischen Akademie der Wissenschaften zu Berlin 1868: 145-148. [systematics as Nothobranchius nov. gen.]

    Ahl, E. 1926. Neue oder selten importierte Fische 1. Blätter für Aquarien un Terrarienkunde, 37 (9): 222. [taxonomy as Fundulus kuhntae]

    Myers, G. S. 1926. A new Cyprinodont fish from East Africa. The Fish Culturist, 6 (2): 91. [taxonomy as Adiniops troemneri]

    Ahl. E. 1935. Über neue oder seltene afrikanische Zahnkarpfen der Gattungen Aphyosemion und Nothobranchius. Zoologischer Anzeiger, 112 (5-6): 126–127. [taxonomy as Nothobranchius mayeri]

    Paepke, H.-J. & L. Seegers. 1986. Kritischer Katalog der Typen und Typoide der Fischsammlung des Zoologischen Museums Berlin. Teil 1: Atheriniformes. Mitteilungen aus dem Zoologischen Museum in Berlin, 62 (1): 135–186. [lectotype designation]

    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 orthonotus. The IUCN Red List of Threatened Species 2019: e.T131804766A47239244. [conservation]