Engraulicypris brevianalis
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Ordo: Cypriniformes
Familia: Cyprinidae
Genus: Engraulicypris
Name
Engraulicypris brevianalis (Boulenger, 1908) comb. n. – Wikispecies link – Pensoft Profile
- Neobola brevianalis Boulenger, 1908. Annals of the Natal Government Museum 1(3): 281. Holotype: unsexed; “Mkuzi River, Zululand, Transvaal [sic]” [BMNH 1907.4.17.90] in formalin [BMNH].
- [[= Engraulicypris whitei|= Engraulicypris whitei]] van der Horst, 1934. Annals of the Transvaal Museum 15(3): 281, unnumbered fig. Syntypes: 5 unsexed, Petronella [SAIAB 30040 ex TMP 15024]; 4 unsexed, Hammanskraal [SAIAB 30041 ex TMP 16022] in formalin [SAIAB].
Material examined
Engraulicypris brevianalis: Holotype, BMNH No 1907.4.17: 90, SL 67 mm. “Mkuzi River, Zululand, Transvaal”. [BMNH]. Engraulicypris whitei: Syntypes, SAIAB 30040 (ex TM 15024) (5) and SAIAB 30041 (ex TM 16022) (4), “Aapies River (Limpopo System) near Petronella and near Hammanskraal (Transvaal)”. Other material, see Table 2.
Diagnosis
Caudal fin membrane clear towards vivid yellow at fork; anal fin extending two thirds of length of caudal peduncle; caudal peduncle moderately long; operculum entirely (not partially) shiny; body midline silver (not black); iris dark to light grey (not white); head with tubercles along lower jaw and lower head in breeding males; snout rounded (not pointed), darker dorsally; pelvic fin melanophores absent.
Morphology
(Figs 6–8; Table 5). Maximum SL 75 mm. Body elongated; somewhat fusiform; laterally compressed. Maximum body depth at middle pelvic and pectoral fin origin. Pre-dorsal profile straight or slightly convex behind head. Head length 20% SL; with tubercles along lower jaw and lower head. Snout rounded; short; 30% of head length. Mouth terminal; slightly crescent-shaped with long anterior side; reaching anterior border of orbit. Nostrils large; level with dorsal margin of eye; separated from orbit by less than one orbit radius. Tubular anterior naris short; adjacent to open posterior naris. Eye lateral; visible from above and below (more prominent); diameter 35% of head length. First gill arch with 8+3 gill rakers on cerato- and epibranchial arms, respectively. Gill rakers long; pointed; widely-spaced. Pharyngeal bones in three rows. Pharyngeal teeth 4,3,2–2,3,4; robust and long; falcate. Modal fin formulae in Table 5. Fins large in relation to body size. Dorsal fin closer to caudal fin than tip of snout; more or less above origin of anal fin; length 17% SL; posterior margin straight; rays soft; anterior-most branched fin ray longest. Pectoral fins largest; reaching 1/2 to 3/4 distance to base of pelvic fin; fin lacking lobe at base. Pelvic fins reaching 2/3 distance to base of anal fin; relatively small; pointed; fin lacking a basal lobe. Anal fin moderately long; extending 2/3 length of caudal peduncle; last unbranched ray longest. Ano-genital opening at anterior of base of anal fin. Caudal peduncle moderately long. Caudal fin forked; lobes with slightly concave interior and extending into point; upper lobe shorter.
Scales small to medium relative to body size; in regular rows; cycloid, slightly elongate; radially striate. Base of anal fin lacking sheath scales. Lateral line present; complete; dipping sharply towards ventral at tip of pectoral fin; joining midline at posterior of caudal peduncle; scale count 53–57 (n = 2) along lateral line, 18 around caudal peduncle.
Live colouration
(Fig. 6). Body silver, without vertical bars or bands. Dorsum pale brown with small dark brown melanophores, midline silver. Snout darker dorsally. Operculum entirely metallic silver. Iris dark to light grey. Dorsal fin membrane clear; rays clear with olive melanophores; fading towards tips. Caudal fin membrane clear, vivid yellow at fork; rays light olive; rays lighter towards tips; melanophores small, dark, fading towards rear. Anal fin rays clear; membrane clear; dark spotting above origin; melanophores dark olive fading towards tips. Pectoral fin membranes clear; rays clear; first ray with few dark melanophores. Pelvic fin rays clear; membrane clear.
Preserved colouration
(Fig. 7). Body and head white and silver with dark spotting sparse to densely packed towards caudal fin on midline and on dorsal surface. Scales on dorsal surface lightly pigmented. Ventral scale pigmentation as intense as dorsal surface. Dorsal surface of head lightly pigmented. Melanophores small, dark; clustered on rear of head, below orbit and on lips and snout; along midline, increasing in intensity to caudal fin; browner on dorsal surface above midline; forming a small, dark line above anal fin. Operculum and posterior edge of orbit with silver sheen. Membranes between fin rays clear. Pelvic fin clear membranes and rays. Dorsal, caudal and pectoral fin membranes clear; rays with melanophores small, dark, widely-spaced; rays pale grey.
Etymology
‘Brevianalis’ alludes to the relatively short anal fin. ‘Whitei’ honours Mr A. G. White, who collected the type specimens in the Aapies River near Petronella and Hammanskraal.
Distribution
Botswana, Zimbabwe, South Africa, Swaziland, Mocambique: Limpopo River, Incomati River, Pongolo River, St Lucia system, Mkhuze River.
Type locality
Mkuzi River (perhaps within 40 km east or west of 27°35'S 32°00'E), South Africa.
Biology
Pelagic species preferring close proximity to substrate and seeking out slacker areas such as backwater, eddies and pools below riffles. Occurs in shoals and prefers well-aerated, open water in flowing rivers (Skelton 2001[1]), favouring the upper stratum (Engelbrecht and Mulder 1999[2]). Feeds from water column on planktonic crustaceans and insects (e.g. midges and ants) (Skelton 2001[1]). Caught at night with light. Breeding occurs in early summer (Skelton 2001[1]). Found in dams where appears to propagate successfully with little predation and moves around in rivers according to seasonal flows. Appears to migrate up streams in spring to breed where it is found in tributaries.
Remarks
The specimen (SAIAB 66270) used by Liao et al. (2012)[3] to represent a DNA sequence of Mesobola brevianalis and is from the Usuthu River (Table 1), and does belong to that species (Fig. 3).
Taxon Treatment
- Riddin, M; Bills, I; Villet, M; 2016: Phylogeographic, morphometric and taxonomic re-evaluation of the river sardine, Mesobola brevianalis (Boulenger, 1908) (Teleostei, Cyprinidae, Chedrini) ZooKeys, (641): 121-150. doi
Images
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Other References
- ↑ 1.0 1.1 1.2 Skelton P (2001) A Complete Guide to the Freshwater Fishes of Southern Africa. Struik Book Publishers, Cape Town, 395 pp.
- ↑ Engelbrecht G, Mulder P (1999) Allozyme variation in the river sardine, Mesobola brevianalis (Pisces, Cyprinidae). Water SA 25: 293–296. http://www.wrc.org.za/Pages/Preview.aspx?ItemID=4315&FromURL=%2fPages%2fDisplayItem.aspx%3fItemID%3d4315%26FromURL%3d%252fPages%252fKH_WaterSA.aspx%253fdt%253d5%2526ms%253d62%253b%2526d%253dVolume%2526e%253d25%2bNo.3%252c%2bJuly%2b1999%2526start%253d61
- ↑ Liao T, Arroyave J, Stiassny M (2012) Diagnosis of Asian Raiamas (Teleostei: Cyprinidae: Chedrina) with comments on chedrin relationships and previously proposed diagnostic characters for Opsaridium and Raiamas. Ichthyological Research 59: 328–341. https://doi.org/10.1007/s10228-012-0296-9
