POTTHOFF ET AL.: DEVELOPMENT OF SCOMBROID FISHES 



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Figure 3.— Schematic representation of vertebral column, dorsal and anal fin, pterygiophore, and hypural development in Nesiar- 

 chus yiasutus, Gempylidae. Cartilage, white; ossifying, stippled. Scale represents interneural and interhaemal space number and vertebra 

 number. 



sal fin pterygiophores. Addition of second dorsal and 

 anal pterygiophores was then in an anterior and 

 posterior direction. The same development was 

 observed for the second dorsal and anal fin rays and 

 anal spines at slightly greater size (Table 2). 



Most gempylid genera lack predorsal bones, ex- 

 cept Tongaichthys (Nakamura and Fujii 1983), 

 Ruvettus (Potthoff s pers. obs.), and Thyrsitops 

 (Sato 1983) which have one predorsal bone. The first 

 dorsal pterygiophore originated from one piece of 



cartilage and inserted in the second interneural 

 space supporting two fin spines (one supernumerary 

 spine). In three Atlantic Lepidocybium, the first dor- 

 sal pterygiophore inserted in the second interneural 

 space, but in two Pacific specimens it was found in 

 the third space. The first anal pterygiophore was 

 considerably larger than the following pterygio- 

 phores and presumably developed from two pieces 

 of cartilage. It supported three anal spines (two 

 supernumerary spines) except in adults of Rexea, 



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