a number of apparently paedomorphic characters (i.e., lower meristic counts), and 

 Its small body size may be represent a derived state. 



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'"'^^' Body Coloration :/^"^ ' 



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Ageneiosids exhibit a wide variety of pigmentation patterns, ranging from 

 species with relatively unspectacular countershading and no prominent spotting or 

 banding to species with very distinctive mottUng or spotting. The coloration pattern 

 is of considerable use in identifying most species, but general descriptions must be 

 interpreted with caution due to pronounced intraspecific variation. 



Prior to this study, it was apparently generally assumed by most authors that 

 species of ageneiosids, like many other fishes, have characteristic pigmentation 

 patterns that varied little among individuals, either temporally or spatially, within 

 the same or between different populations. Many of the early species descriptions 

 emphasized differences in pigmentation from what was published in the literature or 

 apparent in relatively few specimens available for comparisons; in several cases the 

 alleged differences between nominal species were quite subtle. During the initial 

 phases of the present work, I noted extensive variation in pigmentation of several 

 species, and suspected prior to examining types that some names were synonyms on 

 this basis alone; in fact, this is the case, as revealed through examination of a fair 

 amount of material of most species, collected from different areas and varying in the 

 quality of preservation. 



The most extreme case of color variability was observed in y4. vrttafM5 

 collected from flooded caflos in the middle Orinoco basin. The normal 

 pigmentation of fish from this area is relatively light, with one or two incomplete 

 lateral stripes and two large caudal spots, as seen in the specimen on the lower right 



