Thrattidion noctivagus Roberts, 1972
Sanaga pygmy herring
Thrattidion noctivagus
photo by FAO

Family:  Clupeidae (Herrings, shads, sardines, menhadens), subfamily: Dorosomatinae
Max. size:  2.14 cm SL (male/unsexed)
Environment:  pelagic,
Distribution:  Africa: endemic to the Sanaga River at Edea, Cameroon (Ref. 188, 28136, 81631).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 14-16; Anal spines: 0-0; Anal soft rays: 23-25. Diagnosis: Thrattidion noctivagus is distinguished from its congeners by the following characters: posterior supra-maxilla absent, belly rounded; prepelvic scutes 4 to 7, with lateral arms, but without keels; pelvic scute with 2 or 3 lateral arms; postpelvic scutes keeled and with arms; lower gillrakers 10 or 11; pelvic insertion well before dorsal fin, with 7 or 8 finrays; anal fin beginning under dorsal fin base (Ref. 188, 81631). The presence of scutes distinguishes it from Congothrissa gossei and the absence of a second supra-maxilla distinguishes it from all other West or central African pellonulines (Ref. 188). Description: Small and slender or moderately deep-bodied fishes, depth 20-28% of standard length, perhaps not reaching much over 2 cm standard length (Ref. 188). Posterior supra-maxilla absent (Ref. 81631). There are 10-11 gillrakers along the lower limb of the first gill arch (Ref. 81631). Dorsal fin origin a little behind pelvic fin insertion; 14-16 dorsal fin rays; 23-25 anal fin rays (Ref. 81631). Number of scutes: 4-7 prepelvic and 3-5 postpelvic scutes (Ref. 81631). Colouration: Preserved specimens are opaque whitish, lacking melanophores or with a few at the anal fin base and on the caudal peduncle; many melanophores are present in the region of the brain (Ref. 81631).
Biology:  Found in rivers, collected only at dusk and dawn in swiftly flowing water of about 1m just above the hydro-electric dam at Edea, Cameroon (Ref. 188). Feeds on plankton and some terrestrial insects (Ref. 188).
IUCN Red List Status: Data deficient (DD); Date assessed: 05 March 2018 Ref. (120744)
Threat to humans:  harmless
Country info:   
 

Entered by: Binohlan, Crispina B. - 17.10.90
Modified by: Boden, Gert - 17.09.15
Checked by: Binohlan, Crispina B. - 23.07.94

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