As with other members
of family Neptuneidae, this snail has a raised spire,
a well-developed siphonal
canal but the anterior portion of the body
whorl and canal
are not set off from the rest of the body
whorl by a conspicuous groove. It has no anal
notch, less than 8 whorls. Colus
griseus is less than 3x as high as its diameter.
It has both
ridges. The 23-28 low, broad axial
ribs extend onto the body
whorl but disappear or become indistinct on the anterior half
ridges are small and closely spaced and of similar
not have distinct angular shoulders. It has no folds on the columella
nor on the inside of the outer lip of the aperture
(photo). The outer
lip of the aperture
has a concave curve where it meets the siphonal
canal. The siphonal
canal is less than half the total length of the aperture.
The height is up to 3 cm.
Common name(s): Gray whelk
griseus shell collected
dead from a red octopus (Octopus
rubescens) midden. Shell height is 1.5
cm, width 0.7 cm.
|(Photo by: Dave Cowles,
How to Distinguish from
Similar Species: Mohnia
freilei, another rare subtidal species, has 12-15 axial
whorl and only reaches 1.8 cm height.
History: This is
a rare subtidal species.
While Kozloff (1987, 1996) classify this species in
The American Fisheries Society (1998) and ITIS (2008) place it in
1987, 1996 (as Plicifusus
in family Neptuneidae)
Fisheries Society, 1998
General Notes and
abundances, unusual behaviors:
I have not found this species near Rosario, but
octopus have because this was in the beer bottle midden of a red
at about 18 m depth on Whidbey Island.
This photo shows the aperture. The shell has
obviously been dead
for awhile and has the remnants of a bryozoan growing within the aperture
as well as some missing shell on the outer lip of the aperture.
Note how the axial
ribs disappear on the anterior half of the body
whorl, while the finer spiral
ridges are still visible.
This live individual is 2.4 cm long.
is the same individual, crawling along the side of an aquarium at the
surface of the water. Note the extended siphon and the whitish foot
with a horny operculum. Photo by Dave Cowles, August 2018
individual (the same as the 2.4 cm one above) seems perfectly willing
to gradually come out of the shell when I hold it upside-down. .Here
the foot, head with eye, and inhalant siphon can be clearly seen
stretching from the aperture as I hold the shell. Note the hole nearly
bored through the shell near the rear of the foot. Photo by Dave
Cowles, August 2018
Authors and Editors of
Dave Cowles (2008): Created original page
CSS coding for page developed by Jonathan Cowles (2007)