Luke Massey / Giant otter (Pteronura brasiliensis) feeding on a catfish (Loricariidae) with Cocoi heron (Ardea cocoi) scavenging remnants, Rio Cuiaba, Brazil

Remi Masson / Group of Black bullhead (Ameiurus melas) shoaling to protect themselves against predators, River Rhone, Rhone-Alpes, France, July.

Remi Masson / Group of Wels catfish (Silurus glanis) gathered in the River Rhone, France, August.

Anup Shah / Marabou storks (Leptoptilos crumeniferus) feeding on catfish in waterhole, wide angle view. Maasai Mara National Reserve, Kenya.

Georgette Douwma / Kaleidoscopic image of Striped catfish (Plotosus lineatus) school feeding on sea bed. West Papua, Indonesia.

David Hall / Striped eel catfish (Plotosus lineatus), shoal of juveniles. Komodo, Indonesia.

George Sanker / Double-crested cormorant (Phalacrocorax auritus) feeding on Catfish (Siluriformes). Myakka River State Park, Florida, USA. February.

George Sanker / Great blue heron (Ardea herodias) walking with Catfish (Siluriformes) in beak, at dusk. Myakka River State Park, Florida, USA. February. February.

George Sanker / Great blue heron (Ardea herodias) with Catfish (Siluriformes) in beak, at dusk. Myakka River State Park, Florida, USA. February. February.

Shane Gross / School of Striped eel catfish (Plotosus lineatus) move through seagrass, eating the algae growning on the seagrass blades. Manado, Indonesia.

Pascal Kobeh / Wels catfish (Silurus glanis) on the bottom of the river. Its face has a scar probably caused by a fishing hook. Cher River, Loir-et-Cher Department, France

Pascal Kobeh / Two Wels catfish (Silurus glanis) on the bottom of a river. The one on the foreground has a scar on its face probably caused by a fishing hook, Cher River, Loir-et-Cher Department, France