Arothron reticularis
Dark reticulated skin on a chunky puffer, most reliably logged in Phuket, Maluku and Xiaoliuqiu in warm 25-29C water year-round.
Grows to around 31cm and shows a dense, dark reticulated (net-like) pattern covering the back and sides, fading to a paler, often plain belly. The body is the classic rounded, slow-moving puffer shape with a blunt snout and small fins set well back. Look for the fine web pattern rather than bold spots, that's the giveaway against other Arothron species on the reef.
Divers typically find it cruising slowly over sand patches and reef flats or sitting still near rubble and coral rock, often solo. It tends to be unbothered by divers and won't dart off quickly, giving you time for a good look before it eases away. Most logs describe it as an uncommon find worked into a wider reef dive rather than something sought out on its own.
Like other pufferfish, it can inflate its body with water when threatened, a defence that makes it far harder for a predator to swallow.
Sightings don't show a clear seasonal pattern, and with a comfortable water-temperature range of 25.1 to 29.3C it's present on these tropical reefs year-round.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most consistently logged in Thailand, especially around Phuket, and in Indonesia's Maluku region, with a further reliable presence around Taiwan's Xiaoliuqiu and Kenting. Across all three countries it turns up as an uncommon sighting rather than a guaranteed one, so it's a nice bonus rather than a headline target on these reefs.
Mapping where Reticulated Pufferfish is logged…
Best chances are in Thailand around Phuket, Indonesia's Maluku region, and Taiwan around Xiaoliuqiu and Kenting. Even in these spots it's logged as uncommon, so treat it as a possible sighting rather than a sure thing.
There's no strong seasonal pattern in sightings, and it sits comfortably in 25 to 29C water, so it can be seen on tropical reefs across the year.
Look for a chunky, slow-swimming puffer with a fine dark net-like pattern covering its back and sides, fading to a plainer belly. It lacks the bold large spots seen on some other Arothron pufferfish.
They typically reach around 31cm in length, making them a solid mid-sized puffer on the reef, noticeable but not huge.
No, they're not considered dangerous to divers. Like all pufferfish they carry toxins internally as a defence against predators, but this poses no threat to divers simply observing them.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Valentini Pufferfish
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