Crustacean · crab

White vent crab

Bythograea thermydron

PacificAtlanticIndianSouthernArctic A single ocean

Depth

About 2,400 to 2,750 m, around the vents of the eastern Pacific

Size

Carapace up to about 6 cm wide

Diet

Scavenger and grazer: it sweeps up deposits on the worms’ tubes

Zone

The sea floor · 200 – 3,500 m

Key facts

• The adult is white with claws that are almost black at the tip.
• Its larvae have true, image-forming eyes. On becoming an adult, it loses these eyes and keeps a bare retina, very sensitive to the faint glow of the vents.
• Its larvae swim at 4 to 10 cm per second, often faster than the bottom currents, to find a vent.
• Small crabs give way to large ones, especially when there is food.

Verified sources

1. Williams 1980, Proceedings of the Biological Society of Washington, description de Bythograea thermydron
2. Jinks et al. 2002, Nature, Adaptive visual metamorphosis in a deep-sea hydrothermal vent crab
3. Epifanio et al. 1999, MEPS, larves et juvéniles de Bythograea thermydron
4. SeaLifeBase, Bythograea thermydron

In the game: To observe

In the same zone

Kairei blind crabAustinograea rodriguezensis Atlantic vent eelpoutPachycara thermophilum Long-rostrum shrimpAlvinocaris longirostris Methane musselGigantidas childressi (formerly Bathymodiolus childressi) Centenarian tubewormLamellibrachia luymesi Vent octopusVulcanoctopus hydrothermalis