The genus Leptodoras Boulenger is a monophyletic assemblage of at least ten species distributed in large, predominantly lowland rivers throughout the northern half of cis-Andean South America. Leptodoras is diagnosed in Doradidae (thorny catfishes) by unique morphologies of the oral hood (upper labial extensions distinct with comparatively smooth ventral surface, lateral margins of extensions entire, weakly scalloped or fimbriate and without marginal papillae, and interlabial membranes of narrow or moderate width), first gill arch (enlarged accessory lamellae extend well onto medial face of gill filaments), and gas bladder (reduced size and modified cordiform shape, two distinct horn-like diverticula project from posterior walls of posterior chambers, and... |