Table 3. Depth of pectoral fin base and length of pectoral fin relative to body length for larvae of 

 seven scorpaenid genera, expressed as mean percentage and range for three larval stages. 



relative length and in Helicolenus they are small and 

 rounded. In Sebastes there is a great variety in relative 

 size and shape among the numerous species. Also, dif- 

 ferent species attain maximum relative pectoral length 

 at different developmental stages (Table 3). 



Patterns of melanistic pigmentation on the pectorals 

 are useful in identifying larvae to genus and species as 

 demonstrated in the key to preflexion larvae. The pat- 

 terns are too diverse to be summarized here and are best 

 treated in the succeeding sections. 



Anal fin ray counts are not of particular value in dis- 

 tinguishing among most genera of scorpaenids. The usual 

 anal fin count is III, 5 (occasionally III, 4 or in, 6) in 

 Sebastolobus, Trachyscorpia, Helicolenus, Scorpaenodes, 

 Scorpaena, and Pontinus. In Ectreposebastes the count 

 is typically III, 6 with a range of 5 to 7 rays. The number 

 of anal rays has a greater range among species of 

 Sebastes. The typical counts for eastern North Pacific 

 species of Sebastes are HI, 6 and 7, however some species 

 have slightly higher ray counts and S. jordani has III, 8 to 

 11 anal rays. The second of the three anal spines is usual- 

 ly longer than the third and heavier in juvenile and adult 

 specimens. It should be noted that the third anal spine is 

 late in differentiating. When first formed in larvae, it has 

 the appearance of a soft ray. It is not ossified as a spine 

 until the early juvenile stage; however, we have desig- 

 nated the third element in the anal fin as a spine in all of 

 our counts of larvae. The change in the third anal ele- 

 ment to a spine is gradual. Even in a cleared and stained 

 series it is sometimes difficult to determine just when it 

 becomes a spine; however, the total count of spines plus 

 rays in the anal fin remains constant. For example, 

 whether the anal count for larvae of Sebastolobus is 

 given as H, 6 or III, 5, the total count remains 8. An iden- 



tical problem with regard to the change-over of the third 

 element of the anal fin from a ray to a spine is encountered 

 in larvae of Mugil (Anderson 1957, 1958), and striped 

 bass, Morone saxatilis (Mansueti 1958). The anterior two 

 spines of the anal fin are supported in secondfiry associa- 

 tion by a single massive, elongated pterygiophore, pos- 

 sibly the product of the fusion of the first two; the re- 

 maining anal spine and the anal rays ase each supported 

 by a pterygiophore and are in secondary association with 

 the following pterygiophore (except the last ray). The 

 pterygiophore count is two less than the total count of 

 anal spines and rays. 



The number of dorsal fin spines is a particularly useful 

 character (Table 2). The commonest count is XU, found 

 in Scorpaena, Pontinus, Helicolenus, Trachyscorpia, and 

 Ectreposebastes. Species of Sebastes in the eastern 

 North Pacific normally have XHI dorsal spines, as does 

 Scorpaenodes. North Atlantic species of Sebastes have 

 XIV to XVI dorsal spines, whereas Sebastolobus has XV 

 to XVII. The number of dorsal soft rays is usually 9 (8 to 

 10) in Sebastolobus, Trachyscorpia, Scorpaena, Pon- 

 tinus, Ectreposebastes, and Scorpaenodes, 11 to 13 in 

 Helicolenus, and 11 to 16 in Sebastes. The total number 

 of dorsal fin rays and spines is 20 to 22 in Pontinus, 

 Trachyscorpia, and Scorpaena, 21 or 22 in Ec- 

 treposebastes, 22 to 24 in Scorpaenodes, 23 to 25 in 

 Sebastolobus, and 24 to 31 in Sebastes. 



The last spine in the dorsal fin of all the above scor- 

 paenids appears first as a soft-ray and later ossifies as a 

 spine, just as in the third spine of the anal fin. The an- 

 terior two spines of the dorsal fin are supported in second- 

 ary association by a single wide (fused) pterygiophore. 

 In eastern Pacific scorpaenids this pterygiophore lies 

 between neural spines two and three and is always ac- 



