SUMIDA ET AL,: EARLY DEVELOPMENT OF SEVEN FLATFISHES 



Table 9. — Morphometries, in millimeters, of larvae and juveniles of Pleurontchthys verticalis. 

 (Specimens between dashed lines are undergoing notochord flexion.) 



'Sym. - symmetrical. Migr - migrating 



^Str. - straight; E fl - early flexion, fvlidfl - midtlexion; L fl - late flexion, Juv - juvenile 



^Asterisk indicates inclusion of dorsal fin pterygiophores in body depth measurement 



Table lO. — Meristics of larvae and juveniles of Pleurontchthys verticalis. 

 (Specimens between dashed lines are undergoing notochord flexion,! 



Fin ray 



Teeth 



Station 



Size 



(mm) 



Stage' 



Dorsal 



Caudal Pelvic 



Pectoral 

 right left 



Gill 

 rakers 



Upper jaw Lower law 

 R L R L 



6609-97.29 

 7503-90 27 6 



6507-107.30 

 5708-117 26 

 5708-117 26 



5.3 NL 



5.6 



55 



58 



57 



58 



Prefl 

 Prefl 

 Prefl, 

 Prefl 

 Prefl 

 Prefl 



Forming Forming 



Forming Forming 



Forming Forming 



Forming Forming 



Forming Forming 



Forming Forming 



LP2 

 LP-' 

 LP2 

 LP' 

 LP^ 

 LP' 



'Prefl - preflexion, E fl - early flexion, L fl - late flexion: Postfl - postflexton, Juv - juvenile 

 'LP refers to functional larval pectoral tins which have no ossified rays 



differentiate progressively anteriorward. A 

 number of specimens, 5.3-5.8 mm NL with the 

 notochord still straight, possess 2 + 2 or 3 + 3 

 caudal rays. The complete complement of 10 + 9 

 caudal rays is present on specimens 7.0 mm NL 

 and larger. Flexion occurs in larvae between 6.1 

 and 7.0 mm NL (Figure IIB). By the time the 



caudal ray complement is fully formed, the rays 

 are aligned in a terminal position (Figure IIC). 

 The hypurals are observed as cartilaginous plates 

 before they ossify. There are two superior and t\vo 

 inferior hypurals^ in pleuronectid flatfishes. The 



^We mclude the "parhvpural" as a hypural bone. In flatfishes it 

 is a splinter bone without remnant of a haemal arch. 



123 



