“Charro” and “Cowboy” Hermit Crabs

This post was originally posted on the Department of Invertebrate Zoology’s blog No Bones on February 20th, 2013. Thanks Rafael Lemaitre for allowing me to repost. All rights are reserved by Smithsonian National Museum of Natural History.

The Deep Reef Observation Project (DROP) is a Smithsonian initiative in the island of Curaçao which began in 2011 with support from the Consortium for Understanding and Sustaining a Biodiverse Planet.  I have been studying hermit crabs and other crabs that have been filmed or photographed using a manned submersible named Curasub, which can dive down to 300 m in depth. A rich and spectacularly colored  fauna of hermit crabs, never seen before alive in their original habitats, has been discovered.

These three hermit crabs, affectionately called “The Three Amigos” (in reference to the movie starring Steve Martin, Chevy Chase and Martin Short), use tusk shells for housing. The operculate-shaped chelae allows for a tight closure of the shell when the hermit is fully retracted. The scientific name of this species is Pylopagurus discoidalis (A. Milne-Edwards, 1880), a species of the family Paguridae, never before photographed alive [Photo courtesy of Barry Brown]
These three hermit crabs, affectionately called “The Three Amigos” (in reference to the movie starring Steve Martin, Chevy Chase and Martin Short), use tusk shells for housing. The operculate-shaped chelae allows for a tight closure of the shell when the hermit is fully retracted. The scientific name of this species is Pylopagurus discoidalis (A. Milne-Edwards, 1880), a species of the family Paguridae, never before photographed alive [Photo courtesy of Barry Brown]
The DROP program is providing an extraordinary and unique opportunity for taxonomists like me to make direct, live observations of many species that have previously been known exclusively from preserved and colorless specimens in museum collections. The study of these samples, such as those of Pylopagurus discoidalis shown here, is serving to expand and complement collaborative studies on hermit crabs systematic from the Caribbean at large. The specimens are being used to obtain molecular data such as barcodes and DNA sequences, which will be useful for biodiversity assessments, long-term faunal monitoring, and evolutionary studies.

A specimen of Pylopagurus discoidalis (A. Milne-Edwards, 1880), perhaps playing “cowboy” while riding on top of a sea cucumber Holothuria (Vaneyothuria) lentiginosa enodis Miller & Pawson [Photo courtesy of Barry Brown]
A specimen of Pylopagurus discoidalis (A. Milne-Edwards, 1880), perhaps playing “cowboy” while riding on top of a sea cucumber Holothuria (Vaneyothuria) lentiginosa enodis Miller & Pawson [Photo courtesy of Barry Brown]
by Rafael Lemaitre