As a member of family Lyonsiidae,
this species has 2 adductor
muscle scars of similar size. It has no hinge
teeth (photo)and no chondrophore.
The shell has no radial
ribs. The umbones
do not quite touch (photo).
The interior of
the valves is pearly (photo).
line and pallial
sinus are continuous (though often indistinct in this
The tips of the siphons
are not bright red. This species is fragile and nearly
outline or higher than long (but often deformed). The periostracum
is translucent yellowish brown. It is usually found embedded
of compound ascidians with the siphons
exposed. The shell usually cracks when dried. The
fine concentric growth lines, and Johnson
and Snook say it also has fine radiating lines.
Length to 4 cm.
Mytilimeria nuttalli Conrad, 1837
Common name(s): Sea bottle, sea
bottle clam, bottle clam,
|Mytilimeria nuttalli found in the
low intertidal in Guemes Channel
|(Photo by: Dave Cowles,
July 2005). Identified
with the help of Gene Coan
How to Distinguish from
Members of most other families have hinge teeth. Other
family Lyonsiidae such as Entodesma
navicula are longer than high (not circular in
outline) and do
not live in ascidian colonies.
Alaska to Isla Rondo, Baja California, Mexico
Low intertidal to 40
in ascidian colonies
is almost always embedded in compound ascidian colonies, especially Archidostoma
psammion and Cystodytes lobatus.
Larve appear to settle
on the ascidian colony and attach by a byssus. The clam
becomes surrounded by the colony except for a narrow slit for the
The species is a hermaphrodite
but doesn't spawn eggs and sperm at the same time.
and Fairbanks, 1966
and Carlton, 1975
and Snook, 1955
et al., 1980
General Notes and
Observations: Locations, abundances,
Species in this family (Lyonsiidae) have no hinge teeth. This
is the hinge on the left valve. Notice the calcified
that wraps around the hinge ligament from the left valve.
The platelike shield can be more clearly seen in this photo.
The interior of the shell is pearly but the pallial line and pallial
groove are difficult to distinguish.
The shell is fairly inflated, as can be seen in this end-on view of
the left valve. The shieldlike plate which wraps around the
ligament can also be seen.
The species has large umbones which face anteriorly.
The shell is thin, and along the ventral edges is mostly
periostracum. In this view of a live individual, the thin,
periostracum along the ventral margin has distorted when the animal
forming into two nearly parallel plates.
Authors and Editors of Page:
Dave Cowles (2006): Created original page