POTTHOFF ET AL.: DEVELOPMENT OF SCOMBROID FISHES 



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vae and juveniles developed an anal fin in which the 

 rays were of the same length as those in the dorsal 

 fin, but the anal rays became very short and vestigial 

 in adults. In adult Trichiurus the posterior end of 

 the dorsal fin was anterior to the posterior end of 

 the anal fin. Other trichiurids (Benthodesmus, Evox- 

 ymetapon, Lepidopus) examined by us had pte- 

 rygiophore arrangements similar to Trichiurus. 



FAMILY SCOMBRIDAE 



The family is a very speciose group which is 

 divided into two subfamilies (Collette et al. 1984). 

 For the monotypic Gasterochismatinae, larvae were 

 not obtainable, but one or more species for each of 

 the four tribes of the Scombrinae was studied. 



Tribe Scombrini 

 Figure 9 



Twenty-two Scomber japonicus (4.4 mm NL - 9.6 

 mm SL, 100, 103 mm SL) and 12 S. scombrus (5.7 

 mm NL - 8.2 mm SL) were used in this study. Many 

 more Scomber smaller than 5.5 mm NL were avail- 

 able but showed no cartilage development along the 

 notochord. In addition, developmental studies on 

 Scomber by Kramer (1960) and Kohno et al. (1984) 

 were consulted. 



Development of the vertebral column in Scomber 

 initially started in four places on the notochord: 1) 

 posteroventrad (parhypural, hypurals 1 and 2), 2) 

 ventrad at the center (anterior haemal arches and 

 spines), 3) dorsad at the center (neural arches and 

 spines above developing haemal arches and spines), 

 and 4) anterodorsad (neural arches and spines of 

 future centra 1-3). The anterior neural spines were 

 added posteriorly, the neural spines at the center 

 of the notochord were added anteriorly and poste- 

 riorly, the haemal spines were added posteriorly, but 

 the parapophyses were added anteriorly. The hypu- 

 rals were added in a posterior direction, but the two 

 autogenous haemal spines were added anteriorly. 

 The dorsal and ventral areas of development co- 

 alesced completing the cartilaginous ontogeny of the 

 vertebral column. Ossification of the vertebral 

 column (neural and haemal spines, vertebrae, and 

 hypural complex) initially started in four places: 

 1) dorsoanteriorly (anteriormost neural arches and 

 spines), 2) ventrad at the center (anterior haemal 

 arches and spines and posterior parapophyses), 3) 

 posteriorly (hypural complex), and 4) dorsad at the 

 center (neural arches and spines). The four initial 

 areas of ossification coalesced as ossification pro- 

 gressed. Vertebrae in Scomber initially had saddle- 



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