The dwarf pufferfish (Carinotetraodon travancoricus) is a species of pufferfish found in freshwater in Southwest India. They are one of the smallest pufferfish known with a maximum size of 3.5cm. Although closely related to marine pufferfish, they are not found in salt water, and reports to the contrary are based on misidentification.
Both genders are primarily yellow with dark green to black iridescent patches on the flanks and dorsal surface, but as with other members of the genus, some males are more brightly colored than females. Males can also have a dark stripe down the center of their pale belly and iridescent “eye wrinkle” patterns that females do not have. Females are more rounded, tend to be a bit larger than males, and may or may not show more smallish spots between their larger dark markings.
Dwarf pufferfish have become quite popular as aquarium fish thanks to their attractive colors, small size, and relative ease of maintenance. The dwarf puffer is also one of the few aquarium fish to regularly eat small live snails, so it is used in controlling snail populations (larger snails do not interest them). This popularity is a major threat to the species, as it is often wild-caught
The dwarf pufferfish is classified as vulnerable on the IUCN Red List due to habitat loss and overharvesting for the aquarium trade. It remains common in some rivers, but it is rare in others and overall it has been estimated that the species declined by 30–40% from 2005 to 2015. Dwarf pufferfish are found in some reserves such as the Neyyar Wildlife Sanctuary.