Merodoras nheco inhabits a flooded portion of the upper Paraguay River basin in western Brazil called the Pantanal Matogrossense. Here it lives in the lentic lakes in flooded areas.[1]
M. nheco is like other doradids. It has three pairs of barbels (one pair maxillary, two pairs mental), strong dorsal and pectoral finspines.[1]M. nheco is differentiated from all other doradids by having its scutes with thorns directed ventrally in adults, and from all doradids except Physopyxis cristata by having an incomplete lateral line. It has a smooth dorsal fin spine, as opposed to a serrated one; the only other genus with smooth dorsal fin spines is Anadoras. Also, it has a truncated caudal fin.[1] This species grows to a length of 7.0 centimetres (2.8 in) SL.[3]
M. nheco is fed upon by spectacled caimans (Caiman crocodilus yacare) when its habitat dries over the winter, which makes these fish easier to catch.[1] These fish are often hoststotongue worms, which inhabit their swim bladders.[1]
^Eschmeyer, W. N. (2 September 2015). "Catalog of Fishes". California Academy of Sciences. Archived from the original on 3 May 2015. Retrieved 21 September 2015.
