Diagnosis: Body elongate, but variable in depth, belly fairly sharply keeled; total scutes 31-34 (Ref. 188, 81269). Lower gillrakers 70-166 (Ref. 188, 81269). Upper pectoral fin rays white on outer side, the membrane between black (Ref. 188). Sardinella maderensis resembles S. aurita, but pelvic fin with 1 unbranched and 7 branched rays and no black spot on hind part of gill cover, but a faint gold or black area just behind gill opening (Ref. 188). It is distinguished from S. rouxi by having more lower gillrakers, only 30-40 in S. rouxi, and the caudal fin grey, its tips almost black vs. yellow in S. rouxi (Ref. 188).

Description: Body elongate, variable in depth (Ref. 188, 81269, 81631). Lower limb of first gill arch with 70-166 gillrakers (Ref. 188, 81269, 81631). Dorsal fin with 18-21 rays, anal fin with 17-23 rays and pelvic fins with 8 rays (Ref. 81269, 81631). Scales cycloid: 44-47 in a longitudinal series to base of caudal fin; 14-19 prepelvic and 12-14 postpelvic mid-ventral scutes (Ref. 81269, 81631).

Colouration: Alcohol-preserved specimens are silvery (Ref. 81269, 81631). Upper pectoral-fin rays externally white, fin membrane black; caudal fin greyish, caudal tips blackish (Ref. 81269, 81631). No postopercular spot, but a golden or sometimes blackish area just behind gill opening (Ref. 81269, 81631).