[3] C. goeldii is more typical of lowland large rivers where the water may be warmer and deeper, though it may also occur far upstream.

[2] Species of Cheirocerus have a fully ventral mouth with relatively fleshy lips, a broad premaxilla, a crimped gas bladder that appears to have fringe or finger-like projections, and the slender hollow tube extensions on each side of the gas bladder.

[2] C. abuelo has a dusky-gray body colouration that varies from relatively plain to having numerous small brown spots, and usually has a broad, diffuse band crossing the nape at the dorsal fin origin.

[2] This is evidenced by the specialized gas bladder, hypothesized to enhance hearing, and the poorly developed pigmentation.

[2] Diet mostly consists of benthic invertebrates, with chironomid larvae being a dominant component, but also including ostracods and mayfly nymphs.