Spratellomorpha bianalis (Bertin, 1940)
Two-finned round herring
Spratellomorpha bianalis
photo by FAO

Family:  Ehiravidae (River sprats)
Max. size:  4.5 cm SL (male/unsexed)
Environment:  pelagic; freshwater; brackish
Distribution:  Africa: Madagascar (Ref. 188, 3509), probably restricted to the Majunga region (Ref. 33664). Also reported from Kenya coast at Port Tudor (Ref. 188, 117486), but whether this Mombassa material is conspecific with Spratellomorpha bianalis from Madagascar is currently unclear (Ref. 33664).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 14-17; Anal spines: 0-0; Anal soft rays: 16-18; Vertebrae: 45-46. Diagnosis: Body elongate, a little compressed; belly rounded, without pre-pelvic and post-pelvic scutes, but a pelvic scute present with slender vertical arms; gillrakers 26-31; pelvic fin with 1 unbranched and 7-8 branched finrays, well before dorsal fin origin; last two anal finrays separate, forming a distinct little finlet (Ref. 188, 117486, 121271). This species is distinguished from other clupeids by the presence of 2 anal fins, of which the second anal fin comprises 2 finrays (Ref. 188, 121271). Description: Body elongate, a little compressed, belly rounded (Ref. 188, 117486). Body depth 15-22% of standard length; head length 25.2-27.7% of standard length (Ref. 117486, 118219, 121271). Pre-dorsal distance 51-58% of standard length; pre-anal distance 68-75% of standard length; pre-pelvic distance 47-55% of standard length (Ref. 117486, 118219, 121271). Snout pointed, a little shorter than eye diameter; jaws subequal, lower projecting slightly; maxilla longer than snout, reaching vertical through anterior border of the eye; a single supra-maxilla, expanded posteriorly, almost equal in length to maxilla in depth, with a narrow anterior shaft; a single row of conical teeth on pre-maxilla and maxilla (Ref. 117486, 118219). Gillrakers 26-31 on lower part of first gill arch (Ref. 188, 117486, 121280). Dorsal fin with 14-17 rays, dorsal fin origin a little nearer caudal fin base than tip of snout; a double anal fin, first part with 14-16 rays and second part with 2 rays, the last two rays of anal fin separated from others by a gap equal to three rays, anal fin origin nearer to pelvic fin base than to caudal fin base; pectoral fin with 1 unbranched and 11-12 branched rays; pelvic fin with 1 unbranched and 7-8 branched rays; pelvic fin origin in front of dorsal fin origin, nearer to anal fin base than to pectoral fin base (Ref. 94656, 117486, 118219, 121271). Scales: 41-45 scales in a longitudinal series; 8-9 transversal scales (Ref. 117486, 118219, 121271). Abdominal scutes entirely absent, but a pelvic scute with slender lateral arms present (Ref. 188, 117486). Branchiostegal rays 6 (Ref. 121271). Vertebrae 45-46; with 16-17 caudal vertebrae (Ref. 118219, 121271). Colouration: Fresh specimens mainly translucent; dorsal and lateral surfaces very light brown, peritoneum white; a faint, poorly defined, silvery to golden lateral band from operculum to caudal base, widest behind dorsal base, narrower than pupil of eye; a few brown spots on head between orbits, post-orbital surface of head brown; two parallel rows of minute black spots on median dorsal surface from the nape to the dorsal origin and continued from the last dorsal ray to the caudal base; snout and tip of lower jaw faintly yellowish with a few small dark spots; lower jaw, sides of head and operculum silvery; bases of dorsal and caudal fin yellowish, caudal rays with minute orange spots and a few scattered melanophores; two black lines on caudal base and a black streak on the upper border of the caudal peduncle; a row of black spots along base of anal and first two rays of pectoral fin with a few melanophores, rest of fins colourless (Ref. 117486). Preserved specimens with dorsal side brown; a faint, poorly defined, silvery midlateral stripe on the flanks from operculum to caudal base; ventral side whitish; with a sigmoid spot at the base of the caudal fin (Ref. 117486, 118219, 121271).
Biology:  Presumed marine or estuarine (Ref. 188), but its reported presence in Port Tudor, an area where estuarine conditions prevail, would indicate that the species may be confined to estuaries (Ref. 117486) and it is found in fresh and brackish water in Madagascar (Ref. 13333, 117576). Maximum total length 6.0 cm (Ref. 121271).
IUCN Red List Status: Data deficient (DD); Date assessed: 30 June 2016 Ref. (130435)
Threat to humans:  harmless


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