Engraulicypris gariepinus Barnard, 1943

Riddin, Megan A., Bills, I. Roger & Villet, Martin H., 2016, Phylogeographic, morphometric and taxonomic re-evaluation of the river sardine, Mesobolabrevianalis (Boulenger, 1908) (Teleostei, Cyprinidae, Chedrini), ZooKeys 641, pp. 121-150 : 133-135

Engraulicypris gariepinus Barnard, 1943 stat. rev.

Engraulicypris gariepinus Barnard, 1943. Annals of the South African Museum36(2): 220. Syntypes: 2 unsexed (not located), "Orange River and Fish River" [SAM 18722-23] [lost].

Material examined.

SAIAB 193617, 6 unsexed, 2 cleared & stained: SL 43-44 mm. Namibia, Orange River, Noordower, 28°44'50"S 17°36'32"E, 21 October 2006, R. Bills; SAIAB 78822, 7 unsexed, 2 cleared & stained: SL 39-41 mm. Namibia, Orange River, Felix Unite Camp, 28°41'19"S 17°33'20"E, 20 October 2006, R. Bills; 2 unsexed, SAIAB 78805, 42-47 mm. Namibia, Orange River, Houms River Camp Site, 28°52'5"S 18°36'42"E, 18 October 2006, R. Bills; SAIAB 74232, 10 unsexed, 2 cleared & stained: SL 29-41 mm. South Africa, Orange River, Pella Drift lower site, 28°57'47"S 19°6'36"E, 28 January 2004, R. Bills & N. Jones.

Diagnosis.

Caudal fin membrane clear to pale orange towards midline; anal fin extending over three quarters of length of caudal peduncle; caudal peduncle short; 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, with dense dark spotting on tip; pelvic fin melanophores absent.

Morphology.

(Figs 6-8; Table 6). Maximum SL 46 mm. Body elongated; somewhat fusiform; laterally compressed. Maximum body depth before pelvic fin. Pre-dorsal profile straight or slightly convex behind head. Head length 21% SL; with tubercles along lower jaw and lower head. Snout rounded; short; 32% 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 32% of head length. First gill arch with 7+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 6. 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 over 3/4 length of caudal peduncle; last unbranched ray longest. Ano-genital opening at anterior of base of anal fin. Caudal peduncle short; half of length. Caudal fin forked; lobes pointed; upper lobe shorter.

Scales small to medium relative to body size; in regular rows; cycloid, slightly elongated; radially striate. Base of anal fin lacking sheath of enlarged, elongate scales. Lateral line present; complete; dipping drastically towards ventral at tip of pectoral fin; joins midline at posterior of caudal peduncle; scale count 49-51 (n = 2) along lateral line, 14-16 around caudal peduncle.

Live colouration.

(Fig. 6). Body without vertical bars or bands. Dorsum transparent pale brown with melanophores concentrated around dorsal fin; midline silver. Snout with dense dark spotting on tip. Operculum entirely metallic silver. Iris dark to light grey. Dorsal fin membrane clear; rays clear; melanophores fading towards tips. Caudal fin membrane clear to pale orange towards midline; rays dark grey, lighter towards tips; melanophores small, dark, fading towards rear. Anal fin rays clear; membrane clear; pale orange spotting above origin; melanophores few to absent. Pectoral fin membranes clear; rays clear; first ray few dark melanophores. Pelvic fin rays clear; membrane clear.

Preserved colouration.

(Fig. 7). Body and head orange with small dark brown spotting along dorsal surface, midline and above anal fin. Scales on dorsal surface lightly pigmented. Ventral scale pigmentation less intense than dorsal. Dorsal surface of head lightly pigmented. Melanophores small, dark; grouped on rear of head, below orbit, and on lips and snout; along midline, increasing in intensity to caudal fin; brownish on dorsal surface, darkening between origin of pectoral and dorsal fin; forming small dark line above anal fin. Membranes between fin rays clear. Pelvic fin clear membranes and rays.

Etymology.

' Gariepinus ' refers to the Gariep, a San name for the Orange River that means 'Great water’.

Distribution.

South Africa, Namibia: Lower Orange River system, Fish River ( Barnard 1943).

Type locality.

Orange River and Fish River, Namibia ( Barnard 1943).

Biology.

This shoaling fish favours open, shallow water, normally occurring in slack pools and particularly below riffles. Populations found in the lower Orange and Fish Rivers are limited by the Augrabies and Fish River Falls. They are thought to feed mainly on small autochthonous invertebrates (planktonic crustaceans or insects), and are caught in large numbers where they occur. They are restricted to turbid waters, which provide protection from visual predators (R. Bills, pers. obs.).

Remarks.

The two syntypes of Engraulicypris gariepinus Barnard, 1943 were originally stored in the South African Museum, but were moved to the Albany Museum, Grahamstown, South Africa (AMG 106 and 1009) (Eschmeyer 2014). The Albany Museum fish collection has now been moved to SAIAB and these specimens have not been traced (I.R. Bills, pers. obs.). There is no 'exceptional need’ (ICZN, Articles 75.2 and 75.3) for a neotype, since there is only one species of Mesobola in the topotypical river system, and the species is sufficiently physically distinctive that even if another species was introduced, they would be easy to distinguish on the basis of published descriptions.