COLLETTE and RUSSO: SPANISH MACKERELS 



patch wider (Fig. 26a) than in any other species 

 of Scomberomorus. Posterior end of maxilla ex- 

 panded (Fig. 23a) as in S. lineolatus and S. 

 plurilineatus. 



Description. — Lateral line gradually descending 

 to midline on caudal peduncle. Intestine with two 

 folds and three limbs (Fig. 3o). Spines in first 

 dorsal fin 13-15, usually 14 or 15 (Table 9); second 

 dorsal fin rays 19-22, usually 20 (Table 10); dorsal 

 finlets 8-10, usually 9 (Table 10); anal fin rays 19- 

 22, usually 21 or 22 (Table 11); anal finlets 7-10, 

 usually 8 or 9 (Table 11); pectoral fin rays 22-25, 

 usually 23 or 24 (Table 12). Precaudal vertebrae 

 18 or 19, usually 19 (Table 6); caudal vertebrae 25- 

 27, usually 26 (Table 7); total vertebrae 44-46, 

 usually 45 (Table 8). Gill rakers on first arch 

 (1-2)+ (5-11)= 6-13, usually 2 + (7-9) = 9-10 (Ta- 

 ble 5). Morphometric characters given in Table 27. 



Size. - 

 1981). 



Maximum size 120 cm FL, 10 kg (Lewis 



Color pattern. — Munro (1943) provided good de- 

 scriptions of the colors of juveniles and adults from 



TABLE 27. — Summary of morphometric data of Scom- 

 beromorus semifasciatus. FL = fork length, HL = head 

 length. 



Queensland. Juveniles (<100 mm) with cranial 

 regions and upper regions of the back pale green 

 with a bronze sheen and marked with 12-20 broad 

 vertical dark grey bands. Bars confined to region 

 of body above lateral line, number increasing with 

 age. Cheeks and belly silver white. Snout dark 

 slate grey, patch of green above orbit. First dorsal 

 fin jet black with contrasting areas of white in 

 central region. Second dorsal fin cream with 

 yellow anteriorly. Anal fin and finlets transparent 

 white. Caudal flukes creamy white at margins 

 and dusky or blackish near hypural. Pectoral fins 

 dusky. 



With increase in size the bronze-green colora- 

 tion of the back turns greenish blue. The vertical 

 bands on the back are most marked in specimens 

 < 500 mm and in larger fish there is a tendency for 

 these markings to become less distinct, break into 

 spots or fade out more or less completely. Above 

 700 mm, dead fish assume a drab greyish-yellow 

 blotchy appearance with little or no evidence of 

 markings. This uniform grey color apparently 

 accounts for the vernacular "grey mackerel" of 

 Queensland fishermen as applied to older age 

 groups of the species. 



Munro included excellent illustrations of a 451 

 mm specimen and a 140 mm juvenile in his 1943 

 paper (pi. 6, 8). The illustration of the larger 

 individual has been reproduced in Grant (1982 

 and previous editions) and herein (Fig. 66). There 

 is a color photograph of a 470 mm specimen in 

 Grant (1982:pl. 328). 



Biology. — Little is known of the biology of this 

 species other than it forms small schools. Juve- 

 niles ranging in size from 45 to 100 mm are 

 common along the beaches in the vicinity of 

 Townsville, Queensland, during November and 

 grow to twice this size by January (Munro 1943). 

 Larvae (3.3-10.5 mm SL) were described and 

 illustrated by Jenkins et al. (1984). 



Interest to fisheries. — Fish of 60-90 cm are caught 

 on fishing grounds north of Yeppoon, Queensland, 

 in November while smaller age groups are caught 

 in estuaries along the Queensland coast north of 

 Moreton Bay (Munro 1943). It is taken by setnet- 

 ting as well as by trolling and is popularly fished 

 by Queensland anglers in small outboard-powered 

 boats trolling with small lures or cut bait (Grant 

 1982). Together with Grammatorcynus and three 

 other species of Scomberomorus , mackerel fishing 

 is Queensland's second major finfishery with an 

 annual output of about 1,000 tons of whole and 



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