Habitat loss and overharvesting for the aquarium trade threaten wild populations of dwarf pufferfish.

[5] The justification for moving to Carinotetraodon was based largely on osteological evidence and not on the presence of skin keels, which other members of the genus have, but which had not been confirmed in dwarf pufferfish until one year later in aquarium literature.

Auriglobus modestus Leiodon cutcutiaFW "Carinotetraodon" salivatorFW "Carinotetraodon" lortetiFW "Carinotetraodon" irrubescoFW Pao palembangensisFW Pao cochinchinensisFW "Carinotetraodon" travancoricusFW Dichotomyctere nigroviridis Dichotomyctere ocellatus Pelagocephalus marki Canthigaster coronata Canthigaster rivulata Canthigaster jactator Canthigaster valentini Chelonodon pleurospilus Chelonodon patoca Tetraodon miurusFW Tetraodon mbuFW The maximum documented size is 3.5 cm (1.4 in) total length (TL),[9] with individuals typically reaching less than 2.5 cm (0.98 in) TL,[5] making dwarf pufferfish one of the smallest pufferfish in the world.

[8][10] Both sexes are primarily greenish-yellow, with dark green to brown-black iridescent patches on the flanks and dorsal surface.

[2][11] As with other members of the genus, sexual dimorphism is apparent in mature fish, with males being more brightly coloured than females[10] and having a yellow ventral surface.

[12] Males can also have a dark stripe down the centre of their pale belly and iridescent, blue "eye wrinkle" patterns that females do not have.

[12] All pufferfish can inflate, or "puff up", their bodies by quickly ingesting large amounts of water (or air when necessary) into their highly elastic stomachs.

Until 1999, C. imitator was mistaken as the same species, and the two could be found together in aquaria and were widely available in the international aquarium trade, both sold as dwarf pufferfish.

[4] Although closely related to marine pufferfish, they are not found in salt water, and reports to the contrary are based on misidentification.

[5] Inhabiting heavily vegetated waters with beds of gravel and rock or clay loam with silt and sand,[23] the species is reported from 13 rivers in Kerala,[25] lakes such as Vembanad,[26] the Nilambur harbours,[24] and Kallar Stream, part of the Neyyar Wildlife Sanctuary.

[28] The species was also found in inundated brickyards in Puthukkad,[29] as well as ditches, ponds, irrigation channels, and artificial tanks or abandoned water bodies in paddy fields.

[31][32][33] The dwarf pufferfish is officially classified as vulnerable on the IUCN Red List due to declining populations because of damming, indiscriminate deforestation for agriculture, pollution from wastewater, and, primarily, overfishing for the aquarium trade.

Dwarf pufferfish favour insect larvae but will rely on crustaceans and annelids as alternate feed when the availability of preferable prey decreases.

[35] Their diet in the wild mainly consists of small animals such as water fleas, rotifers, copepods, and seed shrimp, and aquatic larvae such as those of Odonata, Hemiptera, mayflies, and flies, with some amounts of plant matter, largely diatoms and green algae.

They will also readily eat live foods such as red and white mosquito larvae and other small animals they would predate in the wild.

[20] Eggs hatch after five days at 27 °C (81 °F), with larvae and fry in captivity initially fed infusoria, Brachionus (a genus of rotifers), frozen bloodworms, and brine shrimp when they are a week old.

[10] Hatched larvae are a mean of 3.15 mm (0.124 in) total length, with eyes incompletely developed and the body a red-brown.

[20] There is no information available on the lifespans of these fish in the wild, but aquarists report specimens live for approximately five years in captivity.

[42][1] Dwarf pufferfish have become popular as aquarium fish thanks to their attractive colours, small size, "puppy dog eyes", and relative ease of maintenance.