Corydoras Identification Guide

Key identification features

• Small, stocky, armored catfish with two overlapping rows of bony plates along the flanks instead of true scales
• Distinctly arched back profile paired with a flat, straight belly
• Short, down-turned mouth surrounded by two pairs of barbels used to sift food from the substrate
• Color and pattern vary enormously by species, from solid bronze or green tones to bold black-and-white patterns or dark horizontal or diagonal banding
• Hardened, locking leading spines at the front of the dorsal and each pectoral fin
• Generally small, with most species staying under 7 cm as adults

Common look-alikes

• Otocinclus: a slimmer, sucker-mouthed algae grazer that lacks the arched, armored, stocky body shape of a true Corydoras.
• Brochis-type relatives: noticeably taller-bodied with more dorsal fin rays than most classic Corydoras, though they are now generally classified within the same genus.
• Similar-patterned Corydoras species pairs, such as the julii and trilineatus complex: near-identical spotted patterns that usually require close comparison of spot arrangement and fin-ray counts to separate reliably.

Where you'll see one

Corydoras species live in shallow streams, slow rivers, and seasonally flooded plains throughout South America, especially across the Amazon and Orinoco basins. They are typically found in loose groups over sandy or leaf-littered bottoms, sifting through substrate for food alongside similarly sized companions.