Tozeuma armatum
Rare and easy to miss, this thin shrimp hides on sea fans in Malaysia's East Coast and West Papua reefs year-round in warm 25-31.5C water.
Roughly 4 cm long with a slender, almost stick-like body that lies flat along a gorgonian branch, making it disappear against the coral's own lines. Colouring runs translucent to reddish or purplish with fine mottled stripes that match the host sea fan's colour, and the body tapers into a long, thin rostrum (the pointed snout between the eyes). It sits motionless with legs tucked close, so the giveaway is usually a slight asymmetry in the branch pattern rather than the shrimp itself standing out.
Spends its time gripping a single gorgonian branch, staying still for long stretches and relying on its colour match rather than fleeing when divers approach. Most sightings come from divers who slow right down and run a torch or magnifying lens along sea fan branches rather than swimming past. It's logged as rare to uncommon at nearly every site it turns up, so treat any sighting as a real find rather than something you can expect on every dive.
Its body shape and colouring track its host gorgonian so closely that experienced macro divers often find it by looking for a branch that looks very slightly out of place rather than for the shrimp itself.
No clear seasonal pattern shows up in the data, and with a comfortable range of 25.5 to 31.5C it's present on its host gorgonians all year round. Any month works, the challenge is finding it rather than timing the dive.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most consistently logged on sea fans in Peninsular Malaysia's East Coast, which accounts for the bulk of recorded sightings, with a second strong pocket in West Papua, Indonesia. Smaller numbers turn up around Singapore's Southern Islands and in Luzon, Philippines, so it's worth a slow scan of gorgonians on any Southeast Asian reef trip.
Mapping where Gorgonian Shrimp is logged…
The strongest sightings come from Peninsular Malaysia's East Coast and West Papua in Indonesia, with smaller numbers reported around Singapore's Southern Islands and in Luzon, Philippines. Look on gorgonian sea fans on reef slopes and walls in these areas.
There's no strong season in the sightings data, and its warm-water niche of roughly 25.5 to 31.5C is available year-round on tropical Southeast Asian reefs, so any month is workable.
Look for a thin, roughly 4 cm shrimp lying flat along a sea fan branch, coloured to match the gorgonian in reddish or purplish mottling with a long pointed snout. It rarely moves, so spotting an odd bump or line on the branch is often the first clue.
They reach around 4 cm in length, with a slender body that makes them look even smaller against a full sea fan.
Yes, they're logged as rare at most sites where divers have found them and uncommon at the rest, so they're a real macro challenge rather than a reliable sighting. Slow, methodical scanning of gorgonian branches with a torch is the best approach.
No, they pose no risk to divers and simply cling to their host gorgonian, relying on camouflage rather than any defence against approaching divers.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Sally Lightfoot Crab
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