The deep-bodied pipefish (Leptonotus blainvilleanus) is a species of marine fish belonging to the family Syngnathidae.

[1] They can be found in shallow estuaries and algal beds along the coast of South America from Ecuador to Argentina.

[2][3][4] Predators of this species include mackerel and the La Plata dolphin.

[5][6] Reproduction occurs through ovoviviparity: the eggs are carried in a pouch under the tail of the male until they hatch.

[9] The fish is named in honor of zoologist-anatomist Henri Marie Ducrotay de Blainville (1777-1850)[10]