Calcinus hazletti
A small, uncommon hermit crab endemic to Hawaii, logged on reefs in 22.4 to 28.4 C water year-round.
A small hermit crab that gives itself away with pale, almost white walking legs against a darker body, hence the common name. It shelters in a scavenged snail shell like other hermits, so most of what you see poking out is the legs, eyestalks and antennae, with the whitish leg colour being the main field mark against the reef rubble it favours. Size in the water is small, more of a spot-the-detail find than a showpiece animal.
Expect to find it tucked into rubble, rock crevices or coral reef nooks rather than out in the open, doing the slow, methodical scuttle and scavenge typical of hermit crabs. It is not a bold or fast mover, so a close, patient look at reef debris is usually how divers spot it rather than it coming to investigate a torch or camera.
It carries a scavenged snail shell as portable armour and has to trade up to a bigger shell as it grows, so the same individual may look different in shell shape and size over its life even though the crab inside stays the same.
No clear seasonal pattern shows up in the sightings, and the observed temperature range of 22.4 to 28.4 C covers Hawaii's reefs comfortably year-round, so there is no strong reason to time a trip around it. Look for it whenever you are diving Hawaii's reef rubble and rock crevices.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Currently logged only in Hawaii, United States, making it a Hawaii-specific find rather than a species you can plan a trip around elsewhere. Divers have recorded it at a small number of sites within Hawaiian waters, so treat any sighting there as a bonus rather than a guarantee.
Mapping where Hawaiian Whitefoot Hermit is logged…
It has only been logged in Hawaii, United States, so it is effectively a Hawaii-only find for divers. Keep an eye on reef rubble and rocky crevices while diving Hawaiian sites.
There is no detected seasonal pattern, and the water temperatures it has been observed in, 22.4 to 28.4 C, span Hawaii's reefs all year. Any time you are diving Hawaii is a fair time to look for it.
Look for a small hermit crab living in a scavenged shell with noticeably pale, whitish walking legs standing out against its body. It tends to sit low in reef rubble or crevices rather than out in open water.
Exact size data is not confirmed, but like most Calcinus hermit crabs it stays small, a reef-rubble dweller you notice by its markings rather than its size.
It is logged as uncommon at the sites where divers have recorded it, and so far only in Hawaii, so sightings are a real find rather than an everyday occurrence. Its conservation status has not been formally assessed.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Sally Lightfoot Crab
2,422 sites
