COLLETTE and RUSSO: SPANISH MACKERELS 



taken in Phnom Penh, Cambodia, 28 January 

 1939. Because this specimen is not known to still 

 exist, data are presented from the original descrip- 

 tion: D XVI + 16 + VII; A 19+ VI; Pi 22; GR 3 + 9 = 

 12. The figure (pi. 6) accompanying the original 

 description clearly shows the deep dip in the 

 lateral line under the posterior part of the first 

 dorsal fin. 



middle of body (D'Aubenton and Blanc 1965:fig. 

 2). 



There is an excellent figure of S. sinensis in 

 Kishinouye (1923:fig. 34) and there are drawings 

 of a juvenile (191 mm FL, fig. 1) and an adult (1,017 

 mm FL, fig. 2) of S. sinensis from the Mekong 

 River in Cambodia in D'Aubenton and Blanc 

 (1965). 



Diagnosis. — The only species of Scomberomorus 

 that has a swim bladder and the only species with 

 an abrupt downward curve in the lateral line 

 beneath the first dorsal fin (Fig. 68). Two spe- 

 cies, S. cavalla and S. commerson, also have 

 abrupt downward curves in the lateral line but 

 they are under the second dorsal fin. The lateral 

 line in the other 15 species descends gradually 

 without any prominent dips. The pectoral fins are 

 large and rounded rather than pointed as in the 

 other 17 species. Palatine tooth patch very narrow 

 as in Scomberomorus commerson and Acantho- 

 cybium. Ventral process of angular moderate, 87- 

 93% as long as the dorsal process, as in S. cavalla. 

 Posterior end of maxilla only slightly expanded 

 as in S. multiradiatus. Ascending process of 

 premaxilla very long as in S. lineolatus and 

 Acanthocybium. 



Description. — Intestine with two folds and three 

 limbs (Fig. 3q). Spines in first dorsal fin 15-17, 

 usually 16 or 17 (Table 9); second dorsal fin rays 

 15-17, usually 15 or 16 (Table 10); dorsal finlets 6-7 

 (Table 10); anal fin rays 16-19, usually 17 or 18 

 (Table 11); anal finlets 5-7, usually 6 (Table 11); 

 pectoral fin rays 21-23, usually 22 (Table 12). 

 Precaudal vertebrae 19 or 20 (Table 6); caudal 

 vertebrae 21 or 22, usually 22 (Table 7); total 

 vertebrae 41 or 42, usually 41 (Table 8). Gill rakers 

 on first arch (1-3)+ (10-12)= 11-15, usually 2 + 

 (10-11) = 12-13 (Table 5). Morphometric characters 

 given in Table 29. 



Size. — Maximum size 200 cm FL, 80 kg in weight 

 (Kishinouye 1923). A length-weight graph for fish 

 up to 120 cm FL and 18 kg was published by 

 D'Aubenton and Blanc (1965:fig. 4). 



Color pattern. — Back greenish blue, belly silvery, 

 fins mostly blackish. Pelvic and anal fins with 

 blackish margins, anal finlets colorless (Kishi- 

 nouye 1923). Large (larger than the diameter of 

 the eye), round, indistinct spots on sides in two 

 poorly defined rows in adults (Fig. 68). Juveniles 

 with saddlelike blotches extending down to about 



Biology. — No information is available on the 

 movements of S. sinensis. Although it penetrates 

 great distances up the Mekong River, D'Aubenton 

 and Blanc (1965) reported that they failed to find 

 the slightest trace of sexual activity in Cambodian 

 freshwater specimens and so they concluded that 

 S. sinensis must reproduce exclusively in the sea. 

 No information is available on eggs or larvae 

 (Richards and Klawe 1972), but D'Aubenton and 

 Blanc (1965) did report on juveniles as small as 166 

 mm FL from Tonle Sap, Cambodia. 



Interest to fisheries. — No catches were reported as 

 S. sinensis by FAO for the period 1979-82 (FAO 

 1984). However, it is a prized food fish in Japan 

 and probably in China as well. Kishinouye (1923) 



TABLE 29. — Summary of morphometric data of Scom- 

 beromorus sinensis. FL = fork length, HL = head 

 length. 



667 



