Hemigrammopetersius
Hemigrammopetersius Pellegrin, 1926
Body depth 2.75-3.85, head length is 3.3-4.05 of the standard length. Prominent lower jaw. Parietal fontanel present. Dental formula [4/6-9 (upper jaw), 8 (lower jaw)], without any lower inner teeth. Outer premaxillary teeth do not alternate with inner row. Cuspids number: upper jaw, outer row from 3 to 4, inner row from 5 to 7; lower jaw, outer row from 4 to 5. Unpaired fins non-filamentous. Dorsal fin II, 8. Anal fin II-III, 13-18. Gill rakers on the lower limb of the first gill arch 10-16. Longitudinal line scales 24-30 + 1-2; transversal line scales [3½-4½ (above lateral line), 2½-3½ (below lateral line)]; scales around caudal peduncle 9-11. Lateral line incomplete: 6-24.
Colour pattern: a black humeral spot. A black lateral band backwards.
Synonyms
Petersius Boulenger, 1899 (partim)
Alestopetersius (Phenacogrammus) Hoedeman, 1951 (partim)
Phenacogrammus (Phenacogrammus) Hoedeman, 1956 (partim)
Type species Hemigrammopetersius pulcher
Petersius pulcher Boulenger, 1909 by subsequent designation of Pellegrin, 1926.
Currently, two species are assigned to the genus Brachypetersius.
Key to species.
- 18 anal fin branched rays; 24 scales along lateral line; 10 gill rakers on lower limb (ceratobranchial) of gill arch.....................H. pulcher
- 13-17 anal fin branched rays; 25-30 scales along lateral line; 112-16 gill rakers on lower limb (ceratobranchial) of gill arch.....H. barnardi
Bibliography
Hemigrammopetersius barnardi (Herre, 1936)
Type and type locality
Petersius barnardi Herre, 1936: 100-101. Type locality: “Beria”. Holotype: CAS-SU 31521. Paratypes: FMNH 47198 [ex SU], MRAC [ex SU], SAM 22275 [now at AMG], CAS-SU 31521.
Synonyms
Petersius barnardi Herre, 1936
Hemigrammopetersius barnardi Poll, 1945
Common names
Afrikaans: Barnard se rower (South Africa)
English: Barnard's robber (South Africa, Global), Sootfin robber (South Africa)
Estonian: Barnardi viidiktetra
Finnish: Tansaniantetra
Nyanja: Tsimbu (Malawi)
Description
Diagnosis: body depth 3.45-3.65 (3.4-3.78) and head length 3.8-4.05 (3.75-3.8) in SL. Dental formula: [4/8-9 (upper jaw), 8 (lower jaw)]. Cuspids number not indicated. Dorsal fin: II,8. Anal fin: II-III,16-17. Gill rakers: 15-16. Scales: 29-30 + 1-2 (longitudinal line); 4½ (above lateral line)/3½ (below lateral line); 10-11 around caudal peduncle. Lateral line scales 7-12 tubes.
Maximum reported size: 70 mm SL.
Colour: a mid-lateral black band from the operculum to the caudal-fin origin, silvery in live specimens. A black band at the anal-fin base. Fins are greyish.
Distribution
Lower Zambezi, Pungwe and Buzi systems. Also upper Shire and Lakes Malawi, Chilwa and Chiuta. Also Lake Nyasa basin: Rovuma and Rufiji (see also Faunafri).
Although possibly locally threatened (for example in Lake Malawi), this species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. This species is also assessed regionally as Least Concern for Eastern Africa.
Major threats: degradation of habitat due to increased sedimentation load may threaten some subpopulations in eastern Africa, though it appears to survive comfortably in degraded environments, such as the Thuchila stream in southern Malawi, where it thrives despite intensive human activities including washing and sand-mining (D. Tweddle, personal observation). Because of its very small size it is not a targeted fishery species but in its shallow water habitats it may be locally affected by intensive fishing with mosquito nets.
Bibliography
Hemigrammopetersius pulcher (Boulenger, 1909)
Type and type locality
Petersius pulcher Boulenger, 1909: 237, fig. 180. Type locality: “Ja River (Cono system) at Bitye”. Syntypes: BMNH 1909.4.29:48-49.
Synonyms
Petersius pulcher Boulenger, 1909
Hemigrammopetersius pulcher Pellegrin, 1926
Alestopetersius (Phenacogrammus) major pulcher Hoedeman, 1951
Phenacogrammus (Phenacogrammus) major pulcher Hoedeman, 1959
Common names
Estonian: Kaunis viidiktetra
Finnish: Tähtitetra
German: Afrikanischer Leuchtrichsalmler
Description
Diagnosis: body depth 2.75 (2.66-2.75) and head length 3.7 (3.5-3.75) in SL. Dental formula: [4/8 (upper jaw), 8 (lower jaw)] [type: 4/8 (upper jaw), 8 (lower jaw)] (see figure below). Cuspids number: [3-4/5-7 (upper jaw), 4-5 (lower jaw)]. Dorsal fin II,8 (II,8). Anal fin III,18 (III,17). Gill rakers: 10 (12-13). Scales 24+1 (24-25) (longitudinal line); 4½ (above lateral line)/3½ (below lateral line) (4½/3½); 10 (10) around caudal peduncle. Lateral line scales 7 (6-9) tubes.
Hemigrammopetersius pulcher: mouth open in lingual view.
Maximum reported size: 58 mm SL.
Colour: a vertical black humeral mark. A wide lateral black band extending from the caudal fin to the median caudal rays. Fins are hyalin.
Distribution
Dja River (middle Congo River basin) in Cameroon. It is probably also known from the Sankum River, Kondue in the Democratic Republic of the Congo (see also Faunafri).
Hemigrammopetersius pulcher is only known from two locations; the Dja River basin in south Cameroon and probably the Sankum River, Kondue. The species may be more widespread than is currently known. More information is needed on the species distribution before an assessment can be made.
Major threats: cobalt mining on the Dja River by scraping of the surface causes a decline of the habitat.
Bibliography
