528 



ONTOGENY AND SYSTEMATICS OF FISHES -AHLSTROM SYMPOSIUM 



Nematistius 



Caranx 



Parastromateus 



Fig. 278. Anterior pterygiophores and associated spines and rays of anal fin (Note relative spacing between last two spines); (a) Nemalislius 

 pectoralis; (b) Senola zonala; (c) Seriolina nigrofasciata; (d) Caranx sexfasciatus; (e) Parastromateus niger. 



into which the premaxiliary teeth fit when the mouth is closed, 

 and the outer series of dentary teeth strongly hooked outward 

 and with spatulate tips. Major ( 1 973) has shown that this dental 

 arrangement facilitates lepidophagous feeding in juvenile Sconi- 

 heroides and, on the basis of stomach content analyses of two 

 species, concluded that at least some Oligoplites have similar 

 feeding habits. Carr and Adams (1972) postulated that inten- 

 tional removal of ectoparasites is also an important activity in 

 juvenile Oligoplites. Presumably such unique dentition facili- 

 tates both types of specialized trophic ecology. 



(25) Interosseous space between coracoid process of dentary 

 and posterodorsal projection of anguloarticular minute or ab- 

 sent. 



(26) Pleural ribs on vertebrae 3 through 7 or 8 attached high 

 on centrum and spatulate in cross-section. 



(27) Posterior dorsal- and anal-fin rays consisting of semi- 

 detached finlets. 



(28) Reduction in number of epurals in caudal fin from 3 to 2. 



(29) Supramaxilla minute or absent. It might be argued that 

 the reductive-loss supramaxilla character state is a synapomor- 

 phy uniting Trachtnotits + Lichia with the Scomberoidini, in 

 which case the well developed supramaxilla of Parana would 

 constitute a reversal. Alternatively, the reductive trend of the 

 supramaxilla in the two taxonomic pairs under consideration 

 might be a simple case of parallelism. In the absence of any 

 other obvious synapomorphy that supports the first hypothesis 



