Cyphomyrus cubangoensis ( Pellegrin, 1936 )

Kramer, Bernd & Bank, F. Herman Van der, 2011, The Victoria Falls, a species boundary for the Zambezi Parrotfish, Cyphomyrus discorhynchus (Peters, 1852), and the resurrection of Cyphomyrus cubangoensis (Pellegrin, 1936) (Mormyridae: Teleostei), Journal of Natural History 45 (43 - 44), pp. 2669-2699 : 2690-2692

Cyphomyrus cubangoensis ( Pellegrin, 1936) (resurrected species)

( Figure 1A–E )

Marcusenius cubangoensis Pellegrin, 1936: 48 .

Cyphomyrus cubangoensis: Jubb 1967: 33 ; Jubb and Gaigher 1971: 15 (synonymy with Cyphomyrus discorhynchus ).

Hippopotamyrus cubangoensis: Taverne 1971a: 104 .

Material examined

See Material and methods section.

Type specimens

Syntypes: (8) MHNG 858.85 (1) ; MNHN 1936–0062 to 0064 (3), 1936-0065 (now 0) ; MRAC [ex MNHN 1936–65 ] (1); NMB 5216 (1) .

Type locality

“ Cubango: Dr. Monard ”. Pellegrin (1936) gives in addition for all fish he studied that originated from the “Bassin du Cubango” (and not from the “Bassin du Congo”): “Les poissons ont été pris pour la plupart à Vila da Ponte ou dans ses environs immédiats, quelques uns à 120 Km. plus au sud mais toujours en territoire portugais, dans le Rio Mbalé, un petit affluent.” The present name of Vila da Ponte is Kuvango. The small town of Kuvango is located in the state/region of Huíla ( Angola) at 14 ◦ 27 ′ 11 ′′ S, 16 ◦ 18 ′ 03 ′′ E .

Diagnosis

nD, median 30–31 (range 28–33); nA, median 22.5–23 (range 21–24); SPc, median 12 (range 10–12); SLS, median 65–66 (range 59–71); LD, mean 0.2613 –0.2797 (range 0.2445 –0.3001) of SL; LA, mean 0.1724 –0.191 (range 0.1649 –0.2086) of SL; CPL, mean 0.2311 –0.2395 (range 0.1943 –0.2532) of SL; CPD, mean 0.2596 –0.2693 (range 0.2151 –0.3299) of CPL; BD, mean 0.2713 –0.2953 (range 0.2413 –0.3388) of SL; PDL, mean 0.5686 –0.5856 (range 0.5475 –0.6071) of SL; HL, mean, 0.2251 –0.2352 (range 0.2073 –0.2697) of SL. Bipolar EOD, of 220–385 µs duration.

Description

Head broadly rounded, lower jaw protruding less forward than upper, with inferior mouth and chin with a short bulbous protuberance. Deep body laterally compressed, with arched back. Long dorsal fin, median number of rays 30–31 (range28–33), originating clearly in front of anal fin, median number of rays 22.5–23 (range (21–24). Dorsal and anal fins obliquely orientated with anterior portion higher than posterior portion. Usually dark band from dorsal to anal fin. Scales extending anteriorly to operculum and pectoral fins. Caudal peduncle slender and subcylindrical over the entire length, usually slightly less than one-quarter of SL. Tail fin with broadly rounded lobes. EOD bipolar and tetraphasic, of 220–385 µs duration (at 25 ◦ C and “5% threshold criterion”; explained in Material and methods).

Colour in preservation

In various shades from ochre to brown. Dark band from dorsal to anal fin usually fading with conservation time in alcohol.

Ecology

Adult specimens prefer larger river channels with soft bottom. Shoaling species. Small specimens also found in rocky environment.

Behaviour

Social, non-aggressive, at night very sensitive to light and shy during daytime (see Scheffel and Kramer 2000, 2006). Excellent aquarium species.

Distribution

Okavango River and delta whole length, Kwando River , Upper Zambezi.

Relationships

Close relatives are C. discorhynchus ( Peters, 1852) as evidenced by the confusion of the two species, and C. wilverthi ( Boulenger, 1898) and C. psittacus (Boulenger 1897) , but none of the Hippopotamyrus ansorgii complex of species included in the genetic studies of Kramer et al. (2004), and Kramer and Swartz (2010: fig. 8).

Etymology

Pellegrin’s species name cubangoensis refers to the Okavango River where he sampled the type specimens .

Remarks

In Jubb 1967: 33 the synonymization of C. cubangoensis ( Pellegrin, 1936) is presented as follows:

“ Cyphomyrus Myers, 1960 .

Cyphomyrus discorhynchus (Peters), 1852 . Distribution: Zambezi River system, warm waters, and south along east coast to the Sabi River.

Synonyms: Cyphomyrus cubangoensis (Pellegrin), 1936 . C. smithersi (Määr) 1962 .”

No further comment is given.

For distinguishing between specimens of C. discorhynchus and C. cubangoensis , the most useful anatomical characters are: longer LD, longer LA, higher number of nD and nA, higher CPD/CPL in C. discorhynchus than C. cubangoensis .

Figures

Figure 1. Members of the Cyphomyrus discorhynchus species complex. (A) Marcusenius cubangoensis Pellegrin 1936, Upper Okavango River, Angola (NMB 5216, syntype); (B) Cyphomyrus cubangoensis (Pellegrin, 1936), Namibia: province Kavango: Okavango River (SAIAB 20384 specimen R1); (C) C. cubangoensis (Pellegrin, 1936), Namibia: Caprivi Strip: Kwando River: