Description:

Dorsal spines: 9 (8 + 1); Dorsal rays: 31-37; Anal spines: 3 (2 + 1); Anal rays: 27-31;

Body elongate, slender and nearly rounded in cross-section. Eye moderately large, with adipose eyelid well developed, completely covering eye except for a vertical slit 
centred on pupil. Scales on top of head extend forward to anterior margin of pupil.  Oral valve membrane at symphysis of upper jaw white in adults. Both jaws without teeth. 
Dorsal fins widely separated. Terminal dorsal and anal soft rays each consisting of a widely detached finlet. Pectoral fin short (tip falling considerably short of a vertical 
lines from second dorsal fin origin). Lateral line anteriorly with a low regular arch,  junction of curved and straight parts below second dorsal fin between 11th to 13th 
soft rays. Scales in curved part of lateral line 58 to 75; no scutes in curved part. Straight part with 18 to 36 scales, followed by 25 to 39 scutes.  

Colour. Bluish-green above, silvery below. Small black blotch on margin of opercle near upper edge. Dorsal fin lobe sometimes dark distally. Anal and pelvic fins pale to 
whitish. Caudal fin yellow-green.

Maturity: Lm unknown. Range unknown. Max Length: 46cm TL, commonly to 25cm TL.
 

Found mainly in schools in open water, occasionally over outer reefs and frequently around islands (depth 0-400m, usually 40-200m). Feeds primarily on zooplankton. 
Eggs are pelagic.
 

This species is not protected or subject to fishery regulations. It is caught in net fisheries where it is an occasional and sometimes numerous component of the catch.

Fischer, W. & G. Bianchi (eds), (1984).  FAO species identification sheets for fishery purposes. Western Indian Ocean; (Fishing Area 51). Prepared and printed with the 
support of the Danish International Development Agency (DANIDA). Rome, Food and Agricultural Organization of the United Nations, vols 1-6.
Froese, R. & D. Pauly. (Eds). (2020). FishBase. https://www.fishbase.se/summary/993 (28/05/20).
Smith-Vaniz, W.F. et al. (2015). Decapterus macarellus (errata version 2017). The IUCN Red List 2015: https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T190117A16510627.en. (28/05/20).

Nevill, J.E.G. (2020). Decapterus macarellus, Mackerel scad. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/decapterus-macarellus-cuvier-1833/ (edited 26/06/22).