Denticeps clupeoides Clausen, 1959
Denticle herring
photo by Noren, M.

Family:  Denticipitidae (Denticle herrings)
Max. size:  15 cm TL (male/unsexed)
Environment:  pelagic; freshwater,
Distribution:  Africa: in West Africa from Ouémé River basin to Niger Delta (Ref. 81268), Cross River (Ref. 85170) and Mungo River in Cameroon (Ref. 81632).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 8-9; Anal spines: 0-0; Anal soft rays: 23-27; Vertebrae: 39-41. Diagnosis: Denticeps clupeoides is closely related to the Clupeidae, characterised by the presence of midventral scutes; it is distinguished from all clupeids by the presence of numerous small denticles on the surface of the dermal head bones (odontodes) and a complete lateral line along the entire length of the sides (Ref. 2848, 81268, 81632, 117233). Unlike the majority of African freshwater clupeids, Denticeps clupeoides lacks a supramaxilla (Ref. 2848, 81268). Description: Body compressed and rather elongate (Ref. 2848, 81268, 81632). About 9 to 10 pairs of gill-rakers on lower portion of first branchial arch, about 4 to 5 on upper segment; especially those on the lower segment very long and slender, forming a filter mechanism with those of the other arches (Ref. 86890, 101724). Dorsal fin with 8-9 soft fin rays, originating above the posterior fourth or third ray of anal fin; the latter very long and comprising 23-27 soft fin rays; pectoral fin with 11-12 rays; pelvic fin with 5 rays (Ref. 2848, 81268, 81632, 117231). Lateral line complete, comprising 37-40 cycloid scales, from pectoral girdle to structural base of caudal fin; 4.5-5.5 scales in transverse series above lateral line, 5.5-6.5 scales below, counted from base of first dorsal ray and from base of pelvic fin, respectively (Ref. 2848, 81268, 81632, 101724). Presence of a series of ventral scutes along belly; 15-20 pre-pelvic and 4-6 post-pelvic mid-ventral scutes (Ref. 2848, 81268, 81632, 101724). Colouration: Preserved specimens are silvery, somewhat olivaceous dorsally; back with a black line running from head to caudal fin; sides with a narrow black stripe extending from gill cover to base of caudal fin, and becoming broader on caudal peduncle (Ref. 2848, 81268, 81632). Live colouration is silvery with a greenish tint on the sides, whitish on belly, and a darker yellowish-grey on back; the blackish pigmented zones at the bases of the scales form a reticulate pattern of vertical rhomboid fields (Ref. 2848, 81268, 81632, 101724). A narrow and ill-defined zone of greenish golden sheen immediately above an equally narrow but very distinct dark green longitudinal band just above the lateral line, from behind the operculum to the base of the caudal fin; the dark band terminates in a greenish black Y-shaped, triangular, or diamond-shaped spot, just in front of the caudal fin; the width of the golden zone varies with the illumination and the angle at which the fish is viewed; sometimes it seems to expand so as to cover and conceal the blackish green band; a fine black line along the base of the anal fin; fins colourless; posterior part of caudal fin base with an orange hue; caudal fin yellowish orange (Ref. 81632, 101724). The eyes reflect light with a conspicuous glimmer; dorsal part of iris orange, ventral part white and pupil black (Ref. 81632, 101724). Digestive system visible, owing to the transparency of the sides below lateral line (Ref. 81632).
Biology:  Found in streams with water of low ionic content; it always occurs in shoals that tend to keep to the middle of the stream, where the current is at its strongest (Ref. 81632, 101724). It is a skilled and untiring swimmer, extremely fast and hence not easily caught (Ref. 81632, 101724). Peak spawning period in Cross River occurs from July to August (Ref. 85170).
IUCN Red List Status: Vulnerable (VU); Date assessed: 11 May 2019 (B2ab(iii)) Ref. (130435)
Threat to humans:  harmless


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