POTTHOFF ET AL.: DEVELOPMENT OF SCOMBROID FISHES 



shaped ossifications similar to those described for 

 Scombrolabrax (Table 2). 



Cartilaginous second dorsal and anal fin pteryg- 

 iophores developed first simultaneously above inter- 

 neural spaces and below interhaemal spaces 17-19. 

 The addition of cartilaginous second dorsal and anal 

 fin pterygiophores was in an anterior and posterior 

 direction. Cartilaginous first dorsal fin pterygio- 

 phores appeared second above interneural spaces 

 5-8 and were added anteriorly and posteriorly, ter- 

 minating anteriorly in the third interneural space 

 and joining with the second dorsal fin pterygio- 

 phores posteriorly. Second dorsal and anal fin rays 

 developed in the same sequence as their correspond- 

 ing pterygiophore, but a little later. The first dor- 

 sal fin spines developed from anterior in a posterior 

 direction, but the anteriormost (supernumerary) 

 spine first developed when seven first dorsal fin 

 spines were already present (Table 2). 



Scomber lacked predorsal bones. The first dorsal 

 pterygiophore originated from one piece of cartilage 

 and inserted in the third interneural space support- 

 ing two fin spines (one supernumerary spine). The 

 first anal pterygiophore was considerably larger 

 than all other pterygiophores, but it originated from 

 only one piece of cartilage supporting two anal 

 spines (one supernumerary spine). The posterior- 

 most six dorsal and anal pterygiophores had mid- 

 dle radials. The last dorsal and anal pterygiophore 

 supported a double finlet and had a posteriorly bi- 

 furcated stay (Table 1). 



In Scomber, caudal development of the cartilag- 

 inous parhypural and hypurals 1 and 2 was first 

 before any other development of cartilaginous 

 haemal or neural arches and spines along the noto- 

 chord. The development of the hypural complex 

 from the first appearance of cartilaginous hypurals 

 to ossification onset was described by Kohno et al. 

 (1984) and our findings are in agreement with theirs. 

 Kramer (1960) described the ossification sequence 

 in the hypural complex of Scomber. In our speci- 

 mens, hypurals 1 and 2 were fusing to a ventral 

 hypural plate before ossification onset. Hypurals 3 

 and 4 were fusing in some larvae before and in 

 others after ossification onset. The neural and 

 haemal elements of preural centra 2 and 3 supported 

 the procurrent caudal rays. A procurrent spur and 

 a basally foreshortened ray were absent in Scomber 

 (Johnson 1975) (Table 1). 



Tribe Scomberomorini 

 Figures 10, 11 



Thirty-nine specimens were available: 9 Scomber- 



omorus cavalla (4.1-6.2 mm NL), 17 S. maculatus 

 (6.1 mm NL - 10.2 mm SL, 40.5-67.5 mm SL), 3 S. 

 regalis (5.3, 6.5 mm NL, 85.0 mm SL), 4 S. tritor 

 (6.0 mm NL - 8.0 mm SL), 6 Acanthocybium solan- 

 deri (6.2 mm NL - 10.8 mm SL). None of the above 

 five species yielded complete developmental series. 

 However, S. cavalla specimens showed the cartilag- 

 inous ontogeny of the vertebral column, of the dor- 

 sal and anal fin pterygiophores and of the hypural 

 complex. The S. maculatus specimens showed the 

 latter phases of pterygiophore and hypural complex 

 development, dorsal and anal fin development, and 

 the ossification of the vertebral column and the 

 hypural complex. Specimens of 5. regalis and S. 

 tritor provided evidence that development for the 

 Atlantic species of Scomberomorus is very similar. 

 Specimens of A. solanderi gave incomplete infor- 

 mation on cartilaginous vertebral column develop- 

 ment, but adequate information on dorsal and anal 

 pterygiophore, on dorsal and anal fin, on hypural 

 complex development, and on the ossification se- 

 quence of the vertebral column. 



Development of the vertebral column in Scomber- 

 omorus initially started in four places on the noto- 

 chord: 1) anterodorsad (neural arches and spines on 

 future centra 1-3), 2) posteroventrad (parhypural, 

 hypurals 1 and 2), 3) ventrad at the center (four 

 haemal arches and spines), and 4) dorsad at the 

 center (six neural arches and spines above initial 

 haemal spine development). The anterior neural 

 spines were added posteriad, the neural spines at 

 the center of the notochord were added anteriorly 

 and posteriorly, the haemal spines were added most- 

 ly posteriorly but a few were added in an anterior 

 direction. All parapophyses were added in an ante- 

 rior direction. The hypurals were added in a poste- 

 rior direction, but the two autogenous haemal spines 

 were added in an anterior direction. The dorsal and 

 ventral areas of development coalesced and thus car- 

 tilaginous ontogeny of the vertebral column was 

 complete. Ossification of the vertebral column ini- 

 tially started in two places: 1) anteriorly (neural 

 arches and spines, and centra) and 2) posteriorly 

 (hypural complex). Ossification of the neural arches 

 and spines and centra was in a posterior direction. 

 In the hypural complex ossification started with the 

 urostyle and proceeded anteriorly to preural cen- 

 trum 3. Then the ventral hypural plate started to 

 ossify followed by the dorsal plate, the parhypural, 

 and the two autogenous haemal spines. Last to start 

 ossification were the epurals, the uroneural, and the 

 neural spines. Vertebrae in Scomberomorus had 

 saddle-shaped ossifications similar to those de- 

 scribed for Scombrolabrax (Table 2). 



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