Rarest Crab in the World (Most Never See It)
Somewhere off the Pacific coast lives a crab so hard to find that an entire state simply banned catching it. Not because it was overfished. Because almost no one has managed to study it properly. That is not even the crab most people mean when they picture something truly rare.
What Is the Rarest Crab in the World?
Rarity splits two ways here. Puget Sound king crab has no commercial fishery at all, making it nearly impossible to find. Blue king crab is Alaska’s rarest managed king crab species, its fishery closed since 1999 with no reopening date.
Puget Sound King Crab: The Hardest to Find:
Scientifically Lopholithodes mandtii, this crab lives along the Pacific coast, from Alaska down to central California, and remains one of the hardest crabs to actually see.
Washington State lists it as a fully protected species. The reason is simple. Very little is known about it, and it takes a long time to mature.
Its color is part of the appeal too, and explains its rarest crab color. The shell is bumpy and rounded, in mixed red, orange, and purple. Few other crabs look anything like it.
Blue King Crab: Alaska’s Rarest King Crab:
The Alaska Department of Fish and Game confirms it directly: blue king crab is the rarest of all king crab species in Alaska.
Scientifically Paralithodes platypus. Its Pribilof Islands population has been under a rebuilding plan since 2004, with no set date for recovery. The directed fishery there has been shut since 1999.
Why Alaska King Crabs Stay Rare:
Not every king crab is struggling equally, and the differences explain the rarity.
Pribilof Island blue king crab and Pribilof red king crab are both federally declared overfished. Directed fishing for both stays closed. St. Matthew Island blue king crab is slowly recovering, though its fishery is still shut.
Red king crab does better overall. Alaska’s Bristol Bay stock supplies most of the red king crab sold commercially, and it is not currently overfished. That is the real difference between a merely uncommon crab and a genuinely rare one: whether the population has recovered.
Top 5 Rarest Crabs in the World:
Here are the top 5 rarest crabs in the world:
- Puget Sound king crab (Lopholithodes mandtii): no commercial fishery, barely studied, fully protected in Washington State.
- Blue king crab (Paralithodes platypus): Alaska’s rarest king crab, fishery closed since 1999.
- Louisea yabassi: a Cameroon freshwater crab presumed extinct for over a century before its recent rediscovery in the Ebo Forest.
- Parathelphusa reticulata: a tiny Singapore swamp crab, barely 40mm across, that only survives in acidic freshwater swamp forest, a habitat almost gone from the island.
- Clinothelphusa kakoota: found in just one patch of Sri Lankan lowland forest under 100 square kilometers, and losing ground as that forest gets cleared.
Are King Crabs Endangered?
Not officially, under any formal endangered listing. But rare and endangered are not the same thing here.
Several blue king crab populations have stayed closed to fishing for over two decades with no fixed recovery date. That is closer to permanent scarcity than a normal fishing pause, even without an official endangered label.
Conclusion:
Two different crabs earn the title, each by a different measure. Puget Sound king crab has no fishery at all, making it the hardest to find. Blue king crab is the rarest king crab species Alaska actually manages, its fishery shut since 1999 with no reopening date in sight.
(FAQs):
A: Unlikely soon, its full protection exists because so little is known about the species, and opening a fishery would need years of study first.
A: Mainly through population surveys, fishery closures, and habitat range. A crab confined to one small site, or with a fishery shut for decades, counts as rare.
A: Louisea yabassi, a small freshwater crab from Cameroon’s Ebo Forest, presumed extinct for over a century before it was rediscovered.
