Diagnosis |
Diagnosis: Body somewhat compressed, fairly deep with depth at pectoral fin more than head length, scutes apparent along belly (Ref. 188, 51442). Upper jaw with a distinct median notch, lower jaw fitting into it; no teeth on palatine and vomer; gillrakers long, thin and numerous, a total of 85 to 155 on first arch, longer than gill filaments (Ref. 188, 6683, 59043). A dark spot posterior to gill opening, but sometimes absent, sometimes followed by several small blotches (Ref. 188, 59043). Alosa alosa resembles Alosa fallax, which has fewer and shorter gillrakers and 7 or 8 black spots along flank (Ref. 188).
Description: Body fusiform and laterally compressed (Ref. 122971). Head large, high, and laterally compressed; a median notch on the upper jaw (Ref. 122971). Gillrakers long, thin and numerous, a total of 85 to 155 on first arch; distinctly longer than branchial filaments in specimens longer than 250 mm standard length; 55-85 gillrakers on lower part of anterior arch (Ref. 188, 6683, 11601, 59043). Number of dorsal fin rays 18 to 21; number of anal fin rays 22 to 27; caudal fin is distinctly forked and homocercal (Ref. 11601, 122971). Large, thin scales; 60-90 well-developed, deciduous cycloid scales on a longitudinal line and 22-26 in a transverse series; scaling is irregular on the longitudinal line (Ref. 11601, 51442, 52923; 122971). A ventral keel of scutes is present (Ref. 51442, 122971).
Colouration: Dark blue or blue-green back, becoming greenish brown or golden to the sides, sides and ventral side are silvery; a single dusky spot behind the gill opening, sometimes absent, and occasionally 1-6 more dusky spots behind it (Ref. 188, 52923, 59043, 88187, 122971). |