Description of a New, Narrowly Endemic South American Darter (Characiformes: Crenuchidae) from the Central Guiana Shield Highlands of Guyana

作者：Lujan Nathan K^*; Agudelo Zamora Henry; Taphorn Donald C; Booth Pieter N; Lopez Fernandez Hernan

来源：Copeia, 2013, 2013(3): 454-463.

DOI：10.1643/CI-12-079

Characidium amaila, new species, is described from rapids of the upper Kuribrong River (Potaro-Essequibo drainage) upstream of Amaila Falls. It is diagnosed from most other species of Characidium by lacking scales on the isthmus and chest, and by having 8-13 premaxillary teeth, the first four pectoral-fin rays noticeably thickened, 34-36 lateral line scales, and branchiostegal membranes that are free from each other across the isthmus. Characidium amaila is further distinguished by its large adult body size (max. = 85.5 mm SL), and by having a tan body base color with a dark midlateral stripe that originates on the upper lip and continues posteriorly to the base of the middle caudal-fin rays, a gray to dark-black dorsum with two horizontal rows of small light spots formed by aligned light-colored scale centers, a dark humeral spot, up to 15 irregular black bars that extend from dorsum to lower sides, a light opercular margin, and fins that are uniformly dusky. Several cranial, vertebral, and swim bladder characteristics also support distinctiveness of the new species.

• 出版日期2013-9-27