ageneiosids; Ferraris (1988) separated ^gene/oms from Tetranematichthys (and all 

 other doradoids) on this basis, but all of the females of Tetranematichthys that I have 

 examined have very short barbels (it is unknown whether males undergo seasonal 

 elongation of the barbel, as mAgeneiosus). Breeding males oiAgeneiosus develop 

 antrorse, tooth-like outgrowths on the dorsal surface of the maxillary bone, which 

 extend along the entire length of the core of the barbel (Fig. 16b-c). The 

 development of hooked barbels is apparently seasonal, as evidenced from large 

 males with normal, filiform barbels during nonbreeding periods, and direct 

 observations from captive specimens (Kopke 1986; Ferraris 1988; L. Finley, 

 personal communication). Males of Tetranematichthys differ from Ageneiosus in 

 having a much more elongate, weakly tuberculate maxillary barbel (Fig. 16a), 

 similar to that found in several auchenipterid genera. Ferraris (1988) invoked the 

 hyperossified barbel as a synapomorphy uniting the "Ageneiosus group" with the 

 "Auchenipterus group" and Trachefyopterus (see phylogenetic relationships). While I 

 agree that sexual dimorphism of the maxillary barbels (and other nuptial structures) 

 represents a shared, derived character among these taxa, I would argue that a 

 paucity of information on sexual dimorphism available for several auchenipterid 

 genera does not at present allow for an unequivocal generalization regarding the 

 distribution of this character state. Suffice it to say, there is no evidence that any 

 other genera develop sharply hooked barbels; thus, the extreme condition in 

 Ageneiosus is regarded as uniquely derived (Ferraris 1988). I interpret the 

 edentulate, elongate maxillary barbels of Tetranematichthys and various genera of 

 auchenipterids to represent a more primitive state relative to the condition in 

 Ageneiosus. 



