Hairy claw boxer crab

Care at a glance

Overview

A peaceful bottom dweller that behaves like the pom pom crab, holding its hairy claws out in the current to trap particles and then combing them off with its mouthparts. It cannot hurt anything and gets eaten by anything with a big enough mouth, so keep it with dwarf shrimp, snails, and small peaceful nano fish only, in a group of several. Feed powdered foods, crushed flakes, and frozen baby brine shrimp on top of the biofilm it grazes, and never use copper. The boxer name is borrowed from the marine Lybia crabs that hold anemones; this one holds nothing but its own hair.

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, in the Ryukyu Islands, from Amami Oshima to Izena, and in southern Taiwan around Tainan and Pingtung. It is sold as a freshwater crab and adults are kept that way in the trade, but its home water carries some salt, so a low dose of marine salt is closer to what it knows and a wholly fresh tank is a guess. Give a group a tank of 20 liters or more with sand, flat stones to hide under, a gentle current, and a mature coat of biofilm, at 22 to 28 C and pH 7 to 8. It is fully aquatic and needs no land, only a tight lid.

Good to know

Ptychognathus insolitus is a small crab in the family Varunidae, described by Osawa and Ng in 2006 from Izena Island and named insolitus, Latin for unusual, because its very broad carapace, long slender legs, and stout gonopods made it look like a different genus. Males reach about 1 cm across, with the biggest measured at 10.1 mm. The males carry long, soft hairs on the claws, the same trait that gives its relative the pom pom crab its name. The larvae develop in the sea, so it does not breed in fresh water and has never been bred in captivity, and the marine species register lists it as a brackish species.

Common questions

Related species

• 

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  1.6 in (4 cm) · 5 gal (20 L)

  1.6 in (4 cm)5 gal (20 L)72–82°F (22–28°C)

• 

  Indo micro crab

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• 

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• 

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• 

  White mandarin vampire crab

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• Purple arm vampire crab

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  0.6 in (1.5 cm) · 10 gal (38 L)

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