blunthead puffer
Sphoeroides pachygaster
Pufferfish with a flat head and a spineless body, living from 50 to 250 m on the shelf, often showing up in commercial fisheries.
Also called: baiacu-cabeça-chata, baiacu, botete chato, blunthead puffer
- maximum
- 40 cm
- depth
- 50–250 m
who is the blunthead puffer
Pufferfish of the family Tetraodontidae, reaching 40.5 cm. It lives on sand, mud and rock bottoms of the continental shelf, usually between 50 and 250 m. Juveniles are pelagic, and adults feed mainly on squid. In southeastern Brazil, the species was caught between 50 and 145 m. It occurs in tropical and temperate seas worldwide; in Latin America, along the Brazilian coast, Uruguay, Argentina, Chile and the Guianas. It shows up in commercial fisheries and is not a target of recreational fishing.
Essential profile. Identification, where it occurs and rules, with data from FishBase and the cited regulations. Season, time of day, technique and bait are added once we have a good source for the blunthead puffer; in the meantime, see the similar species.
identification
Short, deep body, brown on the back and white on the belly, sometimes with dark blotches on the flanks. The skin is smooth, without spines, and the tip of the caudal fin, or the whole lower part of it, is white. The smooth skin and the white tail tip are the marks that best help identify it among the bottom-dwelling pufferfishes.
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Each card shows the day's index (0 to 100) and, below it, a strip with the index for each hour, from 0h to 23h. from poor to excellent.
Essential profile: the index uses a general fish model (weather, sun, moon and tide), without a season or time of day specific to this species.
where found
In Latin America it occurs along the Brazilian coast, Uruguay, Argentina, Chile and the Guianas, on sand, mud and rock bottoms.
Habitat: Sand, mud and rock bottoms of the shelf, usually 50 to 250 m.
coast
rules for the blunthead puffer
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
Conservation: Not on the Brazilian national list (Ministerial Ordinance GM/MMA No. 1.667/2026).
We found no species-specific rule beyond the region's general rules.
catch and release
catch and release Releasing the fish alive, quickly and with a wet hand. During a closed season it isn't always allowed: what the regulation says applies.
It poses no danger to the angler. Like other pufferfish, it has strong teeth fused into plates; remove the hook carefully. Since it comes from depths of up to 250 m, it can suffer barotrauma, so release it carefully. Do not take it home to eat: pufferfish in general may contain toxin.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.02754, b = 2.84; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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sources and references
Essential profile: size, length-weight, depth, countries and conservation come from FishBase and the cited regulations, and the texts were written from those sources. Season, time of day, sensitivities, technique and baits and lures are not included yet, because we did not find a good source for this species.
- scientific FishBase: Sphoeroides pachygaster (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Sphoeroides pachygasterNames by country and language.
- official Portaria GM/MMA nº 1.667, de 27 de abril de 2026: Lista Nacional Oficial de Espécies da Fauna Ameaçadas de Extinção (peixes e invertebrados aquáticos)The species is not on the list. Checked in the DOU of April 28, 2026.
