Ostracion solorense
A small honeycomb-patterned boxfish most reliably found in the Visayas, Philippines, and Sulawesi, Indonesia, on warm reefs year-round.
A small, box-shaped body barely 8 cm long, covered in a fine honeycomb (reticulated) pattern of dark lines over a pale green to grey background. It swims with stiff, almost mechanical fin flutters rather than a normal fish's tail-driven glide, staying close to the reef. Look for the squared-off, rigid body outline rather than a streamlined fish shape, which is the giveaway for the whole boxfish family.
Divers usually spot it picking its way slowly over rubble patches and reef bases, nudging into crevices and sand for small invertebrates rather than schooling in open water. It's not shy exactly, but it tends to hold its ground or ease away rather than bolt, and its odd, rigid-bodied swimming style makes it easy to pick out once you know what you're looking for. Sightings are logged as uncommon at most sites, so it rewards divers who slow down and check rubble and low-relief ground rather than just scanning the reef wall.
Like other boxfish, its body is encased in a fused bony shell rather than flexible scales, which is why it swims so stiffly compared to almost every other reef fish.
No clear seasonal pattern shows up in the sightings, and with a narrow warm-water niche of 28.2 to 29.3 C it's a year-round reef resident wherever the water stays consistently tropical.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most reliably logged in the Philippines, especially across the Visayas and Luzon, with a strong secondary population in Indonesia, particularly Sulawesi and Maluku. Smaller numbers turn up in Timor-Leste around Dili and Atauro Island, plus occasional sightings in Raja Ampat, Solomon Islands, and Malaysia.
Mapping where Reticulated Boxfish is logged…
The most consistent sightings come from the Philippines, especially the Visayas and Luzon, and from Sulawesi and Maluku in Indonesia. Smaller numbers are logged around Dili and Atauro Island in Timor-Leste.
There's no strong seasonal pattern in the sightings, and it favours warm water around 28 to 29 C, so it's present on tropical reefs throughout the year.
Check for a small, box-shaped body around 8 cm long with a fine honeycomb pattern of dark lines over a pale green-grey background. Its stiff, fluttering swimming style and squared-off outline set it apart from normal reef fish shapes.
They stay small, typically around 8 cm long, making them one of the more compact members of the boxfish family divers encounter on reefs.
Its body is encased in a fused bony shell instead of flexible scales, which forces the stiff, almost robotic swimming motion divers notice underwater.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Honeycomb Cowfish
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