• Source: Bythograeidae

The Bythograeidae are a small family of blind crabs which live around hydrothermal vents. The family contains 16 species in six genera. Their relationships to other crabs are unclear. They are believed to eat bacteria and other vent organisms. Bythograeidae are a monophyletic, sister taxon of the superfamily Xanthoidea which split to inhabit hydrothermal vents around the Eocene.




Origins


Due to the lack of fossils found in this group the exact date of origin of Bythograeidae remains unknown. It has been suggested that bythograeidae do not originate from an ancient hydrothermal bathyal groups but instead arose from brachyuran stock that was adapted to shallow hydrothermal vents and then transitioned to deep sea hydrothermal vents around the Eocene.




Distribution


Bythograeidae are almost exclusively found in the East Pacific Rise. Some exceptions include Austinograea alayseae, Austinograea williamsi and the genus Gandalfus which are found in the western Pacific and Austinograea rodriguezensis which is found only in the Central Indian Ridge.




Ecology


The hydrothermal vents where these crabs live are typically short lived, lasting from 10 to 100 years. These are extreme environments, with high temperatures, high concentrations of sulphides, heavy metals, carbon dioxide and an acidic environment. At this depth there is also limited access to light making photosynthesis nearly impossible. Instead, organisms rely on Chemosynthetic bacteria to sustain the vast amounts of life in Chemotrophic ecosystems.
Bythograeidae are omnivorous scavengers, they are believed to eat bacteria and other vent organisms however they can also be found far from active sites.




Species



Genus Allograea Guinot, Hurtado & Vrijenhoek, 2002
Allograea tomentosa Guinot, Hurtado & Vrijenhoek, 2002
Genus Austinograea Hessler & Martin, 1989
Austinograea alayseae Guinot, 1990
Austinograea hourdezi Guinot & Segonzac, 2018
Austinograea jolliveti Guinot & Segonzac, 2018
Austinograea rodriguezensis Tsuchida & Hashimoto, 2002
Austinograea williamsi Hessler & Martin, 1989
Genus Bythograea Williams, 1980
Bythograea galapagensis Guinot & Hurtado, 2003
Bythograea intermedia Saint Laurent, 1988
Bythograea laubieri Guinot & Segonzac, 1997
Bythograea microps Saint Laurent, 1984
Bythograea thermydron Williams, 1980
Bythograea vrijenhoeki Guinot & Hurtado, 2003
Genus Cyanagraea Saint Laurent, 1984
Cyanagraea praedator Saint Laurent, 1984
Genus Gandalfus McLay, 2007
Gandalfus puia McLay, 2007
Gandalfus yunohana (Takeda, Hashimoto & Ohta, 2000)
Genus Segonzacia Guinot, 1989
Segonzacia mesatlantica (Williams, 1988)




References

Kata Kunci Pencarian:

• Bythograeidae
• Gandalfus puia
• Cyanagraea
• Gandalfus yunohana
• Kermadec Islands
• Colin McLay
• Gandalfus
• List of things named after J. R. R. Tolkien and his works
• Austin B. Williams
• Macauley Island