Siokunichthys nigrolineatus
A tiny 6cm pipefish tucked into mushroom coral off Luzon, Philippines, in warm 28.5-29.2C water year-round.
A slender, elongated body barely 6cm long, coloured pale to translucent with fine dark longitudinal lines running along its length. It has the classic pipefish shape: a straight, rigid body and a small tubular snout, rather than the curled tail and horse-like head of a seahorse. Look for it pressed flat against or wound around the folds of a mushroom coral (Fungiidae), matching the coral's ridges so closely it nearly disappears.
Divers find it holding still against its host mushroom coral, relying on camouflage rather than movement to avoid notice. It's an uncommon find even at the one site where it's been logged, so slow, close scanning of coral surfaces pays off far more than open-water searching. Expect it to stay put rather than dart off when approached, as pipefish generally rely on blending in over fleeing.
This pipefish lives in an close association with mushroom corals, using the coral's polyps and skeletal ridges as both camouflage and shelter, a specialised relationship shared by only a handful of pipefish species worldwide.
No clear seasonal pattern shows up in the sightings, and warm water in the 28.5 to 29.2C range holds steady on this reef year-round, so there's no obvious best month to plan around.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Currently confirmed at a single site in Luzon, Philippines, the only place divers have logged it so far. Given its dependence on mushroom corals, it's worth checking similar coral-rich reef flats elsewhere in the Philippines, though no other locations are documented yet.
Mapping where Mushroom-coral Pipefish is logged…
The only confirmed sightings so far are in Luzon, Philippines, where it has been logged clinging to mushroom corals on the reef. It's not yet documented at other sites, so Luzon is currently the place to look.
There's no detected seasonal pattern, and the water stays a steady 28.5 to 29.2C year-round at the site where it's been recorded, so any month is a reasonable time to look.
Look for a thin, straight-bodied fish around 6cm long with fine dark lines running lengthwise, pressed against a mushroom coral. Its rigid shape and tubular snout separate it from seahorses, and its plain lined pattern separates it from the frilly, leaf-like ghost pipefish.
They stay small, reaching around 6cm in length, which combined with their camouflage against mushroom corals makes them easy to swim straight past.
They live in a tight association with mushroom corals, matching their body to the coral's ridges for camouflage, a specialised habit shared by very few pipefish species.
No, they pose no danger to divers. They're small, non-aggressive, and rely entirely on camouflage rather than any defensive behaviour.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Ornate Ghostpipefish
1,155 sites
