Potamothrissa whiteheadi Poll, 1974
Whitehead's sawtooth pellonuline
photo by FAO

Family:  Clupeidae (Herrings, shads, sardines, menhadens), subfamily: Dorosomatinae
Max. size:  4.7 cm SL (male/unsexed)
Environment:  pelagic; freshwater,
Distribution:  Africa: Hombo River, tributary of Lowa River, and Lindi/Tshopo River, Congo River basin, in Democratic Republic of the Congo (Ref. 188, 28136, 93833, 122734).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 14-15; Anal spines: 0-0; Anal soft rays: 19-22; Vertebrae: 42-42. Diagnosis: Body slender, its depth 22-25% of standard length; pre-pelvic scutes not strongly keeled, beginning under or behind base of last pectoral finray, 8-10 pre-pelvic and 6-9 post-pelvic scutes, belly rounded; snout bluntly rounded; lower jaw not projecting, exactly meeting tip of upper jaw when mouth closed, deepest at mid-point of jaw, with small saw-like teeth on each side; pre-maxillae with small teeth pointing downward; maxilla very slender, its blade over 3 times as long as deep, upper edge ridged, lower edge without denticulations; posterior supra-maxilla minute, virtually without anterior shaft; lower gillrakers 14-17; silver stripe along flank, narrower anteriorly (Ref. 188, 28136). The presence of small horny denticles on snout and edges of mouth on the skin of the maxillary is typical for this species (Ref. 188, 93833). It closely resembles Potamothrissa obtusirostris, which lacks dermal denticles on the snout and has more post-pelvic scutes, 9-12 vs. 6-9; Potamothrissa acutirostris has a pointed snout and more gillrakers, 16-18 vs. 14-17 (Ref. 188, 28136). Other pellonulines lack saw-like teeth at the sides of the lower jaw (Ref. 188). Description: Body slender, its depth 22-25% of standard length; head length 23.8-25.6% of standard length (Ref. 188, 93833). Caudal peduncle length 1-1.2 times in its depth (Ref. 93833). Presence of numerous horny denticles on the snout and edges of mouth up to the maxilla region (Ref. 28136, 93833). Interorbital width 1.2-1.4 times in eye diameter (Ref. 93833). Pre-maxillary teeth 20, mandibular teeth 24, maxillary teeth absent, 4-5 teeth on vomer and lingual teeth absent (Ref. 93833). Posterior supra-maxilla very small, with no or short shaft (Ref. 28136). With 14-17 gillrakers on lower part of first branchial arch (Ref. 93833). Dorsal fin with 14-15 rays; anal fin with 19-22 rays; pectoral fin with 13 rays; pelvic fin with 8-9 rays (Ref. 93833). Scales: about 40 in longitudinal series (Ref. 93833). With 8-10 pre-pelvic and 6-9 post-pelvic scutes, pre-pelvic scutes not strongly keeled, beginning under or behind base of last pectoral finray (Ref. 188, 28136). Total vertebrae 42 (Ref. 93833). Colouration: Silvery, especially a lateral band with an underlying pigmented band, narrower anteriorly, more marked on the back; weak pigmentation at base of caudal fin and on both lobes; snout and occiput weakly pigmented (Ref. 188, 93833).
Biology:  It is a riverine species (Ref. 188).
IUCN Red List Status: Data deficient (DD); Date assessed: 05 March 2018 Ref. (123251)
Threat to humans:  harmless
Country info:   
 

Entered by: Binohlan, Crispina B. - 17.10.90
Modified by: Boden, Gert - 09.10.19
Checked by: Binohlan, Crispina B. - 23.07.94

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