| Family: |
Dorosomatidae (Gizzard shads and sardinellas) |
| Max. size: |
10 cm SL (male/unsexed); max.weight: 7.0 g |
| Environment: |
pelagic; freshwater; depth range 8 - 95 m |
| Distribution: |
Africa: Lake Tanganyika (Ref. 188, 3509, 28136), including Lukuga River from Kisimba-Kilia Falls (Ref. 93587) and Moba River (Ref. 45485). Introduced in Lake Kivu between 1958 and 1960 (Ref. 121351); although the introduction was apparently successful, the fish failed to reproduce (Ref. 28136, 36904). |
| Diagnosis: |
Dorsal spines (total): 0-0; Dorsal soft rays (total): 15-16; Anal spines: 0-0; Anal soft rays: 16-17; Vertebrae: 44-44. Diagnosis: Body slender, its depth about 17-22% of standard length; 13-14 pre-pelvic and 8-9 post-pelvic scutes, with pre-pelvic scutes not strongly keeled, beginning behind base of last pectoral finray, but post-pelvic scutes with sharp spines; maxilla blade about 2.25 times as long as its shaft, but not continued forward to hind tip of pre-maxilla; posterior supra-maxilla diamond-shaped or more or less rhomboidal, approximately symmetrical; lower gillrakers long and slender, 36-42; a distinct silver stripe along flanks, broadest over tips of pelvic fins (Ref. 188, 93833). It resembles Limnothrissa miodon of Lake Tanganyika, which is slightly deeper-bodied, has a larger eye, about equal to head length behind eye, and a maxilla blade continued forward to hind tip of pre-maxilla (Ref. 188).
Description: Body slender, its depth about 17-22% of standard length (Ref. 188). Snout narrow and pointed, rather longer than eye diameter, which is 3.5 times in head length; lower jaw slightly projecting; maxillary not or barely reaching vertical from anterior margin of eye (Ref. 2263, 5393). Lower gillrakers long and slender, 36-42; upper gill rakers 16-17 (Ref. 188, 5393). Dorsal fin with 15-16 rays, origin nearly equidistant from end of snout and base of caudal fin; anal fin with 16-17 rays; pelvic fin with 1 unbranched and 7 branched rays, below or a little in advance of middle of dorsal fin (Ref. 188, 2263, 36901, 45485, 93833). Scales small; 36-46 scales in longitudinal series; 13 transverse scales (Ref. 188, 2263, 36901). With 13-14 pre-pelvic and 8-9 post-pelvic scutes; pre-pelvic scutes not strongly keeled, beginning behind base of last pectoral finray; post-pelvic scutes with sharp spines (Ref. 188, 2263, 36901, 45485, 93833). Vertebrae: 44 (Ref. 45485).
Colouration: General body colour whitish, snout and upper side of head olive-yellow, dorsal side yellow-grey; side of head and lateral band silvery; ventral regions white; dorsal and caudal fin greyish (Ref. 36901). A distinct silver stripe along flanks, broadest over tips of pelvic fins, bordered dorsally by a dark line (Ref. 188, 5393, 36901). |
| Biology: |
A pelagic, lacustrine species, forming very large schools (Ref. 188, 36901, 121343). The juveniles tend to stay closer to the shore than those of 5 cm standard length or more (Ref. 188). They appear to spend daylight hours at a depth of 70-95 m, rising up to 8-15 m at night, especially on dark nights (Ref. 188, 36901). These migrations reflect also the plankton migration (Ref. 36901). It feeds on plankton (Ref. 36901, 93960, 121343, 121352), like prawns, shrimps, also copepods, chironomids, diatoms and algae (Ref. 188). It breeds at about 6 cm standard length, with ripe individuals present almost throughout the year, but major spawning in May-June and again in December-January, the adults moving inshore to breed; the eggs sink slowly (Ref. 188). It is caught with seine nets, often using lights (Ref. 188). |
| IUCN Red List Status: |
Least Concern (LC); Date assessed: 31 January 2006 Ref. (130435)
|
| Threat to humans: |
harmless |
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