Hassar is a genus of South American armored catfish in the thorny catfish family, Doradidae, found in river basins from Brazil north to Trinidad and Tobago. Species in the atlas range from about 8.5–12 in and share the family's rows of bony lateral scutes running down the flanks, along with long, sensitive barbels used to find food by feel over soft or sandy river bottoms at night. Like other doradids, Hassar is capable of producing audible sound — a stridulation made by moving the base of the pectoral spine against the shoulder girdle, amplified through the swim bladder — which is why doradid catfish as a family are sometimes nicknamed "talking catfish."
Hassar sits at the edges of the aquarium hobby rather than at its center — it is far less commonly traded than showier doradids, and none of the five species in the atlas has widespread common-name recognition beyond the generic "Hassar catfish" tag on Hassar orestis. Where it is kept, it is treated as a peaceful, nocturnal scavenger for larger community setups rather than a centerpiece fish. Conservation status leans favorable: three of the five species in the atlas are Least Concern, with one Vulnerable and one not yet evaluated.