shells have a long,
and short, raised spire
outside of the shell is smooth
and polished because the animal's mantle typically covers the outside
the shell. The anterior end of the aperture
has a small siphonal
notch (picture, picture),
but it has no anal
notch. The species has two folds on the columella (photo) and
has a white columellar callus near the anterior end (visible near the
which extends about 1/3 the length of the shell. Callianax
biplicata is one of the largest olive shells on the Pacific
of them are very large), and can get up to 3 cm long, though on our
I have rarely found one over 2 cm. Its foot is white or cream
Callianax biplicata (Sowerby, 1825)
Common name(s): Purple olive shell,
|Callianax biplicata, Dana Point, CA
|(Photo by: Dave Cowles,
How to Distinguish from
Similar Species: Callianax
baetica is more narrow and is usually brown, plus is mostly
and is rarely found on exposed beaches. C. biplicata
has purple coloration on it, even when worn (picture).
typically has wavy longitudinal lines on the shell.
Geographical Range: Vancouver
Bahia Magdalena, Baja California
Depth Range: Low
intertidal to 50 m
bottoms, lagoons, bays.
Burrows in sand,
leaving a plowed trail behind it (photo).
The foot is wedge shaped to facilitate plowing (photo).
While burrowing it raises its long siphon up through the sand as a
Found nearshore on fairly quiet, protected beaches and farther offshore
on more exposed beaches. Predators include the seastars Pisaster
brevispinus and Astropecten armatus, octopus,
and gulls. The snail digs or crawls rapidly or somersaults if
brevispinus tube feet. Primarily found
along the open coast
rather than in protected waters such as Puget Sound. Most
at night, often move up and down the beach with the tide.
animals live higher on the beach than smaller ones do. May
in large clusters (photo).
Probably omnivorous. Will eat kelp blades and live and dead
material. May eat small detritus. Males find
females by following
their tracks, then glues himself temporarily to her shell.
takes up to 3 days. Egg capsules are about 0.5 mm, are
individually on small stones, shells, etc. Grow to 1.6 cm
1-5 mm/year thereafter. Live 8-15 years. May be
by trematode larvae (in the gonads--may castrate host). May
high levels of heavy metals such as copper, lead, silver, cadmium, and
1987, 1996 (as Olivella biplicata)
and Carlton, 1975 (as Olivella biplicata)
and Fairbanks, 1966 (as Olivella biplicata)
et al., 1980 (as Olivella biplicata)
1993 (as Olivella biplicata)
and Hanby, 2005 (as Olivella biplicata)
1994 (as Olivella biplicata)
General Notes and
Observations: Locations, abundances,
Olive shells are often found worn in shelly debris on the
Photo by Dave Cowles, Catalina Island, CA May 1995
Olive shells have a long narrow aperture and a siphonal
Photo by Dave Cowles, Catalina Is., CA 1995
This species is of special value to the Makah indian tribe at
This individual (above and below) was found at Toleak Point, on the
open Washington coast. The scale in millimeters, with
Note that there are two folds on the columella,
and that the white callus on the anterior (right) end is about 1/3 the
total length of the shell.
|The following photos show Callianax
biplicata actvity on sandy regions of Shi Shi
Beach. All the
photos can be enlarged for a closer look by clicking on them.
|Ths is an aggregation of Callianax
biplicata seen in late July. There was a wide
sandy area the
individuals could have occupied but nearly all the individuals were
in a this and a few other small areas near the zero tide
photo was taken at daybreak in late July, 2008 by Dave Cowles.
|Most of the individuals in the aggregation at left were
buried in the sand as can be seen on the left and right in this
A number of them, however, were incompletely buried as seen in the
The center individual is burying itself posterior end-first in the
and is extending its inhalant siphon up toward the surface.
|This individual is crawling across the beach.
Unlike the other
photos in this set, this one was taken in 2007, of an individual not in
an aggregation. The individual was buried in the sand at the
of the trail but I popped it out for the photo. Photo by Dave
at Shi Shi beach, near dawn in early August 2007.
|This individual appears to have previously been in or
at the burrow
at the right which is still occupied by another individual.
is crawling around among the burrows on the left. This was
only individual in the aggregation that appeared to have been visiting
other burrows. Because of the tight aggregation of
the evidence of visiting burrows, I assume that this is a mating
|This member of the aggregation is crawling across the
the plowlike configuration of the anterior foot, which would help the
to burrow through sand. Note also the white incurrent
siphon, which is extended forward, and the dark tentacle-like
of the mantle which is held across the top of the shell.
|This individual member of the aggregation appears to be
lying on its
left side with its foot and mantle extended around the anterior and
end. Note how the inhalant siphon is extending back toward
burrow. I wonder if this individual is preparing to dig into
sand next to the individual in the burrow.
This photo shows a 1.7 cm-long individual crawling along
in the lab. Notice the raised incurrent
siphon and the extended mantle.
Photo by Dave Cowles, February 2014
Authors and Editors of Page:
Dave Cowles (2005): Created original page