Taxonomy & naming
Auriglobus nefastus was described by Tyson Roberts in 1982. The Catalog of Fishes (Eschmeyer, CAS) recognises the current valid combination as Auriglobus nefastus (Roberts, 1982), the parenthetical authority reflecting Roberts's original placement in a different genus.
The genus Auriglobus belongs to the family Tetraodontidae and holds a handful of small, brackish to freshwater puffers of South and Southeast Asia sometimes called the golden puffers. Historical literature may index the species under Chonerhinos nefastus or an earlier Tetraodon combination; both are synonymised under the current Auriglobus. The broader genus Tetraodon, once used as a catch-all for Asian puffers, is now restricted to African species under the revised classification followed by the Catalog of Fishes — the Asian groups have been redistributed into Dichotomyctere (the brackish green spotted and figure-eight puffers), Pao (the Mekong river puffers), Leiodon, Carinotetraodon (dwarf puffers), and Auriglobus.
The specific epithet nefastus is Latin for 'unlawful' or 'wicked' — an allusion that may reference the fish's aggressive temperament, its toxicity, or simply the author's descriptive convention. Precise type-locality details from the original description have not been recovered in the available literature.
Morphology
Auriglobus nefastus has the compact, near-spherical body plan characteristic of the family Tetraodontidae: a rounded, scaleless body that tapers to a small caudal fin, large eyes set high on the head, and the four fused dental plates that form the beak — two upper, two lower — from which the family takes its name. The skin is smooth and lacks true scales, and the gill covers are reduced to small apertures.
Size data for this species specifically are sparse in the accessible literature; genus Auriglobus species typically reach somewhere in the range of 1–3 in total length, making them small even for tetraodontids. Body colouration is broadly golden to bronze-yellow above with a paler belly — the golden or bronze pigment that gives the group its trade name — though precise colour descriptions from specimens are not confirmed in the recovered sources. Like all puffers, the species can inflate its body by rapidly drawing in water as a defence against predators, a reflex that should never be triggered in captivity by lifting the fish into the air.
Habitat
Auriglobus nefastus is a brackish-water species native to coastal South or Southeast Asia. The genus Auriglobus is associated with tidal rivers, estuaries and mangrove-fringed creeks, habitats that shift between freshwater at the ebb of the dry season and full brackish conditions on tidal influence. The exact type locality and precise range of A. nefastus have not been recovered in the available sources; the genus as a whole spans the coastal lowlands and river mouths of the Indo-Pacific region, and Roberts's 1982 description places the species in this broad Southeast Asian brackish zone, with Borneo and Sumatra among the probable candidate localities.
These estuarine and tidal habitats are typically warm, with temperatures in the high twenties Celsius, and water chemistry that ranges from hard and alkaline to brackish depending on tidal state and season. Specific gravity, pH and temperature tolerances for this species in particular are not confirmed in the recovered literature.
Feeding
Like all tetraodontids, Auriglobus nefastus is a predator on hard-shelled invertebrates — molluscs, crustaceans and similar prey whose shells it cracks with its continuously growing beak. The diet of this species specifically has not been documented in the recovered literature, but the family-wide pattern is consistent: puffers are opportunistic predators that will also take worms, small fish, and any suitably sized animal prey.
The beak is the defining feeding organ and a central husbandry concern. Unlike mammalian teeth, the fused dental plates of tetraodontids grow continuously throughout life; without adequate hard prey to wear them down through normal feeding, the beak overgrows and eventually prevents the fish from closing its mouth or feeding at all. In extreme cases the beak must be trimmed under sedation.
Mating
Reproductive behaviour in Auriglobus nefastus is essentially undocumented. The species is rarely maintained in captivity and has not been the subject of published breeding observations. No spawning accounts are available in the accessible hobby literature or scientific literature recovered for this species.
Within the broader family Tetraodontidae, mating systems range from unsupervised egg-scattering with no parental investment to substrate spawning in which the male guards the eggs; there is no bubble-nesting or mouthbrooding in the family. Which strategy applies to Auriglobus nefastus is not known. Observers who maintain this species in suitably brackish conditions may encounter spawning behaviour, but no confirmed account exists in the literature available.
Breeding
No breeding record for Auriglobus nefastus in captivity has been located in the available sources. The species is seldom exported and is among the rarest Auriglobus in the hobby, which likely explains the absence of husbandry accounts. Aquarists attempting to breed this species would be working in largely undocumented territory.
Based on the broader family pattern, eggs — if the species spawns like other brackish tetraodontids — would likely be deposited on a substrate and possibly guarded by the male, but this is inference from family-level biology and not confirmed for this species. Data on incubation period, clutch size and larval requirements are absent from the literature recovered. Any successful breeding accounts would represent a genuine contribution to knowledge of this poorly documented taxon.
In the aquarium
Auriglobus nefastus is very rarely seen in the hobby and represents a significant care challenge even for experienced puffer keepers. Its brackish requirements place it in a specialised niche: the aquarium must be maintained at a salinity comfortably within the brackish range — typically a specific gravity of around 1.005–1.010 is appropriate for Auriglobus, though precise tolerances for this species are unconfirmed — using marine salt. Fresh water alone is not appropriate.
The continuously growing beak demands a diet of hard-shelled food: live or frozen snails, small mussels, cockles, shrimp and similar shellfish should form the core of the diet to keep the beak worn to a functional length. Soft foods are insufficient for this purpose. Puffers are also messy, heavy-waste eaters and require strong biological filtration and generous water changes to maintain water quality.
Temperament is a serious consideration. Auriglobus species, like most puffers, are aggressive fin-nippers and predatory by nature; housing this fish with other species risks injury or predation on tankmates. A species-only or single-specimen setup is the safest approach. The fish should never be removed from the water into air — the inflation reflex triggered by air contact stresses the fish severely. Puffers are also sensitive to copper-based medications, which are lethal at concentrations that other fish tolerate; any medication regime must exclude copper. The skin and organs of tetraodontids contain tetrodotoxin, a potent neurotoxin, so the fish should be handled thoughtfully and is not safe to handle with broken skin.
Conservation
Auriglobus nefastus has not been formally assessed by the IUCN Red List and carries a status of Not Evaluated (NE). Its precise range is not confirmed in the recovered literature, which makes any population-level assessment difficult. The estuarine and tidal habitats on which the genus Auriglobus depends are among the most heavily impacted coastal environments in Southeast Asia, subject to land reclamation, mangrove clearance, coastal development, pollution from agricultural runoff and urban expansion, and disruption of tidal hydrology by infrastructure.
Collection pressure for the aquarium trade appears low — the species is rarely exported — but habitat degradation across the coastal lowlands of its presumed range is a long-term concern for all the small, site-faithful estuarine fishes of the region. A formal IUCN assessment would require better distributional and population data than are currently available in the accessible literature.