THE BIOLOGY OF WOOD-BORING TEREDINID MOLLUSCS
385
in size and position, in the form of the ventricle and in the length of the
auricles. It may be placed ( 1 ) towards the anterior end of the body as
in such genera as Bactronophorus, Neoteredo, Dicyathifer, Teredothyra,
Teredora, Uperotus, Psiloteredo and also in species like Teredo fulleri,
Lyrodus pedicellatus, L. takanoshimensis, L. mediolobata, Bankia gouldi,
B. australis, B. setacea and B. campanellata; (2) in a median position as
in Kuphus polythalamia, Teredo furcifera, T . clappi, T . navalis, T .
pculifer, Lyrodus massa, Nototeredo norvagica, N . knoxi, N . edax,
Spathoteredo spatha and S. obtusa; or (3) posteriorly as in Nausitora
fusticula, N . hedleyi and N . dunlopei.
The length of the heart in relation to the total length of the animal
dso varies greatly, Neoteredo reynei having an unusually long heart in
contrast to the remarkably short heart of Nausitora hedteyi. There is
also considerable variation in the length of the ventricle in relation to
that of the auricles. For example in Dicyathifer manni the ventricle is
short, broad and inflated, but in Bactronophorus thoracites it is long and
thin, the auricles in both are almost identical. I n Teredora princesae
the ventricle is drawn out into a long tubular portion attaining a length
almost three times that of the auricles whereas in Nausitora hedleyi and
N . dunlopei where the heart has moved posteriorly along with the gills
the auricles and the ventricles are of almost equal length. Also the
auricles may be heavily pigmented as in Nausitora dunlopei, lightly
pigmented as in N . hedleyi, or apparently not pigmented at all as in
Teredofurcifera. Even though the general layout of the heart and the
main blood vessels is generally similar, differences in detail are discernible. Thus Turner (1966) has noted in Teredppoculifer and Nototeredo norvagica that the tubular aorta extend anteriorly from the
pericardium and branch just posterior to the posterior adductor muscle.
In Spathoteredo and Nausitora the aorta immediately expands into a
broad, thin-walled vessel which spreads over the dorsal surface of the
visceral mass. Kuphus is unique in having a bulbous area anterior to
the ventricle-the ventricular bulb separated by a large valve for the
ventricle, the aorta opening from its dorsal surface and the intestine
passing through it. Roch (1932) observed the pulsations of the heart in
Teredo navalis. In the quiet animal the author counted one contraction
every 2 sec at 17OC, when the animal was disturbed heart action stopped
for 60-90 sec. In Bankia indica (Nair, 1964) the heart pulsates at the
rate of about 68 timeslmin when kept at room temperature (28-30°C).
Manwell (1963) has shown the presence of myoglobin with concentrations of up to 2% in the adductor muscle of both Bankia and
Teredo. Its presence is indicated by the pinkish hue especially of the
posterior adductor muscle of live specimens. The presence of myo-
385
in size and position, in the form of the ventricle and in the length of the
auricles. It may be placed ( 1 ) towards the anterior end of the body as
in such genera as Bactronophorus, Neoteredo, Dicyathifer, Teredothyra,
Teredora, Uperotus, Psiloteredo and also in species like Teredo fulleri,
Lyrodus pedicellatus, L. takanoshimensis, L. mediolobata, Bankia gouldi,
B. australis, B. setacea and B. campanellata; (2) in a median position as
in Kuphus polythalamia, Teredo furcifera, T . clappi, T . navalis, T .
pculifer, Lyrodus massa, Nototeredo norvagica, N . knoxi, N . edax,
Spathoteredo spatha and S. obtusa; or (3) posteriorly as in Nausitora
fusticula, N . hedleyi and N . dunlopei.
The length of the heart in relation to the total length of the animal
dso varies greatly, Neoteredo reynei having an unusually long heart in
contrast to the remarkably short heart of Nausitora hedteyi. There is
also considerable variation in the length of the ventricle in relation to
that of the auricles. For example in Dicyathifer manni the ventricle is
short, broad and inflated, but in Bactronophorus thoracites it is long and
thin, the auricles in both are almost identical. I n Teredora princesae
the ventricle is drawn out into a long tubular portion attaining a length
almost three times that of the auricles whereas in Nausitora hedleyi and
N . dunlopei where the heart has moved posteriorly along with the gills
the auricles and the ventricles are of almost equal length. Also the
auricles may be heavily pigmented as in Nausitora dunlopei, lightly
pigmented as in N . hedleyi, or apparently not pigmented at all as in
Teredofurcifera. Even though the general layout of the heart and the
main blood vessels is generally similar, differences in detail are discernible. Thus Turner (1966) has noted in Teredppoculifer and Nototeredo norvagica that the tubular aorta extend anteriorly from the
pericardium and branch just posterior to the posterior adductor muscle.
In Spathoteredo and Nausitora the aorta immediately expands into a
broad, thin-walled vessel which spreads over the dorsal surface of the
visceral mass. Kuphus is unique in having a bulbous area anterior to
the ventricle-the ventricular bulb separated by a large valve for the
ventricle, the aorta opening from its dorsal surface and the intestine
passing through it. Roch (1932) observed the pulsations of the heart in
Teredo navalis. In the quiet animal the author counted one contraction
every 2 sec at 17OC, when the animal was disturbed heart action stopped
for 60-90 sec. In Bankia indica (Nair, 1964) the heart pulsates at the
rate of about 68 timeslmin when kept at room temperature (28-30°C).
Manwell (1963) has shown the presence of myoglobin with concentrations of up to 2% in the adductor muscle of both Bankia and
Teredo. Its presence is indicated by the pinkish hue especially of the
posterior adductor muscle of live specimens. The presence of myo-