FISHES OP FAMILY BLENNIIDAE 61 



area between the scajjula and coracoid. The path followed has been 

 to move the radials ventraUy off the scapula and gradually set them 

 on the coracoid. Thus, the 2-1-1 radial formula is the most primitive 

 for blenniids; and the 1-0-3 formula, the most speciaUzed. As noted 

 above, in blenniids, the 2-1-1 formula occurs only in the Blenniini 

 and Omobranchini. As discussed under dentition, jaws, and caudal 

 structure, the Blenniini appear to contain the most primitive blen- 

 niids; the Omobranchini are considered to be derived from them. 



Pelvic pins. — Each blenniid pelvic fin comprises a spine (visible 

 only in osteological preparations) and two to four simple, segmented 

 rays, except in the nemophidinid genera Plagiotremus and Lembei- 

 chthys, each monotypic. Plagiotremus lacks pelvic fins or girdle en- 

 tirely. Lembeichthys has greatly reduced pelvic fins that may comprise 

 a spine and only a single ray (material for clearing and staining was 

 unavailable). AU the blenniids except some of the Nemophidinae 

 have weU-developed pelvics. Reduced or otherwise abnormally formed 

 pelvics are found commonly in individual specimens of many of the 

 genera of the Nemophidinae. Such reduction or malformation is 

 probably the result of the group's having become free-swimming; 

 the pelvics no longer function as a pedestal for support as it does in 

 the other blenniids, which are benthic inhabitants, and, thus, there 

 is no selective advantage in having pelvic fins. 



Nemophidinae with normal pelvics have a fin formula of 1,3. In 

 the Blenniinae the Blenniini usually have 1,3 (secondarily 1,4) pelvic 

 rays; the Omobranchini have 1,2 pelvic rays; and the Salariini have 

 1,2 to 1,4 pelvic rays. A variation of plus or minus one ray from the 

 modal number for any species is found commonly only in the Blenniini. 



It would appear that a pelvic fin ray count of 1,4 would be the 

 most primitive for blenniids inasmuch as it most closely approximates 

 the 1,5 condition of the less specialized perciEorms. However, none of 

 the other, usually considered less specialized, families of the Blenniicae 

 have pelvic fins with more than 1,3 rays (most have 1,3), and only a 

 relati^'ely few species of the Blenniidae have 1,4 rays. While it is 

 conceiveable that these blenniid species have retained a more primi- 

 tive number of pelvic rays, I think it more probable that they have 

 added a ray to the basic 1,3 blennioid pelvic condition. In Hypleuro- 

 chilus geminatus, a relatively specialized member of the Blenniini, 

 the pelvic count is strongly modal at 1,3, but individuals with 1,4 

 rays are not rare. It seems that the addition or subtraction of a 

 pelvic ray in blenniids would not be a development ally diflBcult 

 process. 



Distinctive Characters of the Blenniidae 



The family Blenniidae can be distinguished from aU other blen- 

 nioids on the basis of any one of at least three characters, the first 



