This small hermit crab has
an abdomen that is not coiled (photo) and symmetrical uropods
The palm (propodus)
of the right chela
is little if any wider where the dactyl
and palm join than it is at the proximal end. The right chela
only slightly larger than the left (photo).
The legs have reddish-brown bands. The right and left halves
telson are not separated by a groove (photo).
Carapace length up to 6 mm.
Discorsopagurus schmitti (Stevens,
Common name(s): Tubeworm
|Discorsopagurus schmitti from 15 m
depth, Coffin Rocks.
Animal is in a tubeworm tube that is heavily overgrown with a white
tunicate. Leg span in photo approximately 1 cm.
|(Photo by: Dave Cowles,
How to Distinguish from
The palm of the right chela of Orthopagurus minimus
is wider at
the origin of the dactyl than it is at the base, and it is usually
in the shells of scaphopods (tusk shells). Its right claw is
larger than the left and it holds it straight out in front of itself
Sitka Sound, AK
to Puget Sound; Japan
Mostly subtidal; low
intertidal to 220 m
In tubes of serpulid or sabellarid
tubeworms (usually Sabellaria cementarium or Serpula
vermicularis), rarely in snail shells.
Inland waters and
live in attached tubes, and males in broken-off tubes. Can
feed using both the third maxillipeds and the antennae, plus catches
pieces of drift material.
1952 (as Orthopagurus schmitti)
General Notes and
Observations: Locations, abundances,
This view shows the entire tube and tunicate the hermit crab is
The total mass is so large that the hermit crab can barely crawl
Photo by Dave Cowles, August 2005
Animal out of the tube. Note the straight abdomen, the many
on the body, and the star-shaped pleopods. Note also the two
rear walking legs.
Total length about 2 to 2.5 cm.
In this ventral view of the thorax one can see the relative sizes of
the right and left chelae, the three long first walking legs and the
short rear walking legs, and the abundant setae.
In this ventral view of the abdomen one can see the star-shaped
on the left side, the symmetrical uropods, and the telson which does
have a median groove.
I am guessing that this is a female, and that the star-shaped
are for holding eggs. Although the animal was in a
tube, it was so heavily overgrown that the animal could barely crawl.
Another individual, collected at about 130 m depth from the channel
between Lopez and San Juan Islands, is living in a tubeworm tube which
is encrusted with stones and tiny barnacles. Photo by Dave
A closeup of the same individual.
Authors and Editors of Page:
Dave Cowles (2005): Created original page