Hairy claw boxer crab

Care at a glance

Overview

The hairy claw boxer crab is a small, peaceful bottom dweller that combs its food out of the current, much like the pom pom crab. It is a step up from the easiest crabs.

Caring for the hairy claw boxer crab

Give a group of hairy claw boxer crabs a tank of at least 5 gal (20 L), with sand and flat stones to hide under. Add a gentle current and let a mature coat of biofilm build up. This crab is fully aquatic and needs no land, only a tight lid.

Keep the water at 72 to 82°F (22 to 28°C) with a pH of 7.0 to 8.0, and never use copper. It is sold as a freshwater crab, and adults are kept that way in the trade. Its home water carries some salt, though, so a low dose of marine salt is closer to what it knows. A wholly fresh tank is a guess.

It holds its hairy claws out in the current to trap particles, then combs them off with its mouthparts. Feed powdered foods, crushed flakes and frozen baby brine shrimp on top of the biofilm it grazes.

It cannot hurt anything, and anything with a big enough mouth can eat it. Keep it only with dwarf shrimp, snails and small, peaceful nano fish.

Males carry long, soft hairs on the claws. The larvae develop in the sea, so it does not breed in fresh water and has never been bred in captivity.

Good to know

Ptychognathus insolitus is a small crab in the family Varunidae, described by Osawa and Ng in 2006 from Izena Island. It was named insolitus, Latin for unusual, because its broad carapace, long slender legs and stout gonopods made it look like a different genus. The boxer name is borrowed from the marine Lybia crabs that hold anemones, but this one holds nothing but its own hair. The marine species register lists it as a brackish species.

In the wild

The hairy claw boxer crab comes from the brackish lower reaches of small rivers and estuaries, where it hides under stones on sandy mud. It lives in the Ryukyu Islands, from Amami Oshima to Izena, and in southern Taiwan around Tainan and Pingtung.

Common questions

Related species

• 

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• 

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• 

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• 

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• 

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