Certain aspects of the respiration rate of the
cirratulid polychaete, Cirriformia spirabrandha (Moore,1904)
Elizabeth Gladfelte.
Hopkins Marine Station of
Stanford University
Pacific Grove, California
ACKNOWLEDGEMENTS
wish to thank Dr. John Pearse for his help,
patience and encouragement throughout the course of this
project. I also thank Jim Childress for technical ad-
vice and his generosity, in loaning equipment. This pro-
ject supported in part by the Undergraduate Research
Participation Program of the National Science Foundation
Grant GY-4369.
ABSTRACT
1.. The respiration rate of Cirriformia spirabrancha
(Moore, 1904) is dependent on size and temperature.
2. C. spirabrancha acclimates at 21°0, but respination
rate becomes depressed at 700.
3.. In a sealed chamber, the respiration rate decreases and
thenincreases to initial value as the oxygen tension
decreases from 100% to 0%. This indicates the possibility
that C. spirabrancha can regulate its oxygen consumption.
(warburg, O analger, winker
4. The three techniques used to measure respiration rate
yeilded slightly different results, perhaps due to the
excited state of the worm during the experiments.
5.. An activity pattern was observed,but its cycle was
not determined.
INTRODUCTION
Some previous work has been done on polychaete respir-
ation.. Both Nicol (1964) and Prosser (1962) give tables
of respiration rates. Courtney (1958) determined rates
for Cirriformia (Audouinia) tentaculata and Cirratulus
cirratus, two cirratulids.. Less work has been done on
the ability of polychaetes to regulate under low oxygen ten-
sions. The oxygen consumption of Nereis virens is direct-
ly proportional to oxygen tension (Amberson,1924). Courtney
found the two cirratulid speciesshe studied also conformed.
The ability to regulate may be related to mode of life, but
in studies done thus far this does not seem to be the gener-
al rule (Hyman,1930).
Cirriformia spirabrancha (Moore,1904) is a cirratulid
polychaete which inhabits fine sand and mud (Ricketts and
Calvin, 1962).. Under normal conditions,, it remains buried
with only its tentacles above the suface. The oxygen
content of such mud is very low. Jones (1955) determined
oxygen content of interstitial water from mud of a similiar
nature in a study on Nephthys. He found .11-.35 ml 0/liter
at 15°0, only 2%-6% oxygen satüration. During this project
the respiration rate of C. spirabrancha and its ability
to regulate under low oxygen tensions were determined.
MATERIALS AND METHODS
Specimens of C. spirabrancha were collected once a
week from + 1.0' M.L.T. level of the mudflat areas by
Fisherman's wharf at Monterey, California. They were kept
in finger bowls, filled with substrate from the same area.
These were placed in tanks which were supplied with fresh
flowing sea water and an air supply. Worms to be used in
experiments were washed, blotted dry and weighed. For some
experiments the tentacles were removed with scissors.
Acclimitized worms Were kept in finger bowls without
substrate, into which fresh seawater flowed..
Three methods of measuring oxygen consumption were
employed.
A. Warburg apparatus. One animal was placed in a 25 ml
flask with O.5 ml of 30% KOH supplied in a well to absorb
CO.. The volumn of the worm and seawater equaled 2.5 ml.
This was attached to a manometer and placed in a constant
temperature water bath. The system was continually shaken
except when readings were taken.
B.. Oxygen analyzer. A Beckman electrode was inserted in
a chamber, made of lucite plastic.. Constant temperature was
maintained by means of water from a constant temperature
bath circulating through a jacket surrounding the chamber.
The electrode was inserted through a small opening near
the bottom oftthe chamber, and sealed with lubriseal. A
flow past the electrode was maintained by a stirbar,, and a
magnetic stirrer. The animal was protected from this flow
by placement on a screen resting on a small plastic table
(with a small opening for circulation throughout the tank).
The chamber was covered by another peice of lucite. An
O-ring made the system airtight when the two pieces of lucite
were bolted.. This system was covered by a black cloth, to
prevent interference by photosynthesizing organisms present
in seawater. Two sized chambers were used. Thirty-one hours
were required for a.30 gm worm to use theoxygen in a
214 ml chamber,, while a.26 gm worm required 18 hours to
consume the oxygen in a 58 ml tank.
The electrode was connected by a Beckman 496260 adaptor
to a Beckman Model 76 pH meter. Oxygen was measured as %
saturation. Before each run the electrode was calibra-
ted.. The 100% reading was obtained by bubbling air through
the water until the needle read a constant maximum value
(at which point the water was supersaturated) and then
removing the air source and allowing the needle to fall,
until a steady reading was reached, at which time the
oxygen in the water was in equilibrium with the air.. For
the 0% reading nitrogen was bubbled through the water until
the lowest constant value was reached. This normally took
between 30 and 60 minutes.
C.. Winkler.. Eight to ten animals were placed in a 60 ml
glass stoppered bottle.. This was closed and placed in
an appropriate temperature bath.. The worms were allowed to
respire for two hours, removed and the water analyzed by the
Winkler method (Giese,1964). At each temperature a control
bottle, with no organisms, was also tested.
RESULTS
Figure 1 shows the relationship of size to respir-
ation rate. Although this conforms to the general rule,
that larger organisms have a lower metabolic rate than
smaller ones (Zeuthen,1953),, it is not very pronounced
in C. spirabrancha. Animals without tentacles have a
respiration rate comparable to those with tentacles.
Fluctuations in rate were observed in each experi-
mental animal. This rhythm has not yet been defined.
Readings taken at 5,115, and 30 minute intervalsoshow
similiar patterns,, with peaks occuring about every other
reading. The magnitude of fluctuations using the Warburg
apparatus was tenfold; twofold fluctuations occured in
readings of the oxygen analyzer.. Figure 2 shows the pattern
in one worm, testédiby the warburg method.
Under low oxygen tensions, every specimen of C. spira-
brancha would show a behavioral response. Tentacles be-
came fully extended, and the body would be stretched out.
This increase in surface area gave a greater area for
gaseous exchange.
Animals in closed chambers, with a continually decreasing
oxygen supply, show an initial decrease in respiration rate,
but thenan increase back to the initial rate. Figure 3
shows this pattern for one animal with tentacles and one
Uithout. Twoexperiments were run on animals with tenta-
cles, two on animals without from 100% to 0g.. Three experi-
ments were run on animals without tentacles from 30% satur-
ation to 0%. The results were similiar to the last 30% of
the 100% to 0% runs. Bacterial contamination may have affected
these results.
C.. spirabrancha acclimated at 700 had a lower respira-
tion rate at each temperature studied than those kept at
higher temperatures.(Fig. 4) Those acclimated at 2100 had a
lower rate than the 15°0 worms just exposed to that temper-
ature.
DISCUSSION
Respiration
C. spirabrancha appears to be well adapted to its envi-
ronment.. Although it can get a normal supply of oxygen
through its body wall, as many other annelids (Dales,1963),
its main means of respiration is through its tentacles.
Courtney determined that the tentacles alone are sufficient
for full oxygen exchange.. Flatteley (1916) also noted
that the tentacles probably had a respiratory function.
The behavioral response to oxygen poor water is very
striking. Eventually almost all the tentacles become fully
drawn out in an apparent effort to increase absorptive
surface area. If these conditions continue the worm moves
to the surface of the sand and stretches its body, since
it, too, can act as an area of gaseous exchange.. However,
under completely anaerobic conditions, the worm curls its
tentacles and remains quiet (Findly,1968).. Return to an
oxygen rich environment results in greatly Ancreased tentacle
movement,, and eventual reburrowing into the substrate.
Nothing definite can be said about the ability of C.
spirabrancha to regulate because of the possible contami-
nation by bacteria. Courtney found C. tentaculata had
a rate of one half normal at 40% saturation and no uptake
at 15%,, while Cirratulus cirratus (which is about the same
size as the C. spirabrancha which were used in this study)
had a rate of one half normal at 60% saturation and no
consumption below 40%. If bacterial contamination was
significant,, and only the decrease in respiration is consid-
ered, C. spirabrancha was about the same as Cirratulus
cirratus.
However, assuming no contamination, C. spirabrancha
with and without tentacles could regulate to 3%.. The runs
from 30% to 0% lasted only six to eight hours,, which would
not give bacteria sufficient time to multiply. These indicate
that this worm can regulate.
C.. spirabranche shows a size-weight relationship,
but not as dramatically as some other cirratulids (Court-
ney,1958) .. Glycine uptake, also related to surface to vol-
umn ratio showed only a slight correlation to size (Hubbard,
1968).. The tentacles might affect this relationship since
an increase in their number (and corresponding surface area)
could compensate for the decrease in surface to voulmn ratio
that a larger worm might experience.
The rhythm in the respiration rate was found to exist
in all the methods of measuring oxygen uptake. Some poly-
18
chaetes show well defined activity rhythms. Arenicola
has a forty minute activity cycle (Wells,1949).. The large
amount of water thrust through the burrow once each cycle
provides fresh water for respiration.. Of three genera
studied by Mangum (1964) only one, Clymenella, showed an
activity pattern. The body wall of C. Spirabrancha shows
spontaneous activity (Rohlf,1968). These may be related
to some as yet undefined activity cycle in this polychaete.
The studies on acclimation seem to indicate that the
metabolism of these worms at low temperatures becomes depressed.
This is rather unusual as many animals which have become
acclimatized at a low temperature will gradually increase
metabolie rate so it aill be greater than animals immediate-
ly subjected to a lower temperature (Prosser,1962).
Stongelocentrotus purpuratus shows a relatively high rate
of feeding when first placed in 7°0 water, but after two
weeks, the rate is greatly decreased (Pearse, pers.comm.).
Cold acclimated worms showed a depressed rate even at higher
temperatures for two hours.. Apparently, this is not suffi-
cient time for recovery from the depressed rate maintained
at 7°0.
Worms acclimated to 2190 had a lower rate at this
temperature than worms from normal 15°0 seawater. This
is an expected result in temperature acclimation.
Methods
The three methods employed resulted in different
respiratory rates (compare graphs).. This may be an
indication of the usefulness in using these methods to de-
termine the actual oxygen needs of these animals in their
environment. The Warburg was very artificial since 1)
the animal had very little water and 2) theg were sub-
jected to constant shaking. They were able ti "burrow"
in the screen in the oxygen analyzer, which may be impor-
tant, as these animals appear tp be quite thigmotactic..
The water in the chamber was moving.. Another difficulty
in using the closed chember is the CO effects. At low
oxygen tensions the worm has been in the chamber for many
hours, so the concentration of C0, might be quite high.
This factor is important in measuring the rates of a
planerian (Hyman,1930), but caused no difficulty in the work
on Nereis virens (Amberson,1924).. It does not appear to be
a factor in the present study, as long and short runs give
the same result at low oxygen tensions.
The Winkler method gave intermediete results. The
respoiration of a group of animals rather than individuals
was analyzed. The animals were disturbed by placing them in
the bottle, and this may have caused a slightly higher rate,
Although the Warburg may have resulted in excited animals,
studies can be made to determine size-weight relationships.
The oxygen analyzer is better for determining the actual
oxygen requirements of the animal and also studying its
ability to regulate.
BIBLIOGRAPHY
Amberson,W.R. Mayerson,H.S, and Scott,W.J.(1924) "The
influence of oxygen tension upon metabolic rate in inver-
tabrates."Jour.. Gen. Physiol.7,171-176.
Courtney,W. (1958) The Cirratulid Polychaetes. pp.91-118.
unpub.thesis, University of London.
Dales,R.P. (1963) Annelids. p.77.. Hutchinson University
Library,London.
Findly,R.C. (1968) Research Report for Biology 175h,
Hopkins Marine Station, Pacific Grove, California.
Flatteley,F.W.(1916) "Notes on the ecology of Cirratulus
(Audouinia) tentaculata (Montagu)". J.Mar.Biol.Ass.U.K.
11,60-70.
Giese, A.C.(1964) Laboratory Manuel in Cell Physiology. p. 41.
The Boxwood Press,Pittsburgh.
Hubbard,M.(1968) Research Report for Biology 175h, Hopkins
Marine Station.. Pacific Grove, California.
Jones,J.D.(1955) "Observations on the respiratory physiology
and on the haemoglobin of the polychaete genus Nephthys,
with special reference to N.. hombergii (Aud and M.Edw).
J.Exp.Biol.. 32,110-125.
Mangum,C.P.(1964) "Activity patterns in metabolism and
ecology of polychaetes. "Comp.Biochem.Physiol. 11,239-255.
Nicol,J.A.C.(1960)The Biology of Marine Animale. pp. 152-153.
Sir Isaac Pitman and Sons Ltd,London.
Ricketts,E.F, and Calvin, J.(1962) Between Pacific Tides,ed.3.
p.. 266. Stanford University Press, Stanford.
Rohlf,D.(1968)Research Report for Biology 175h, Hopkins
Marine Station.. Pacific Grove,, California.
Prosser,C.L, and Brown,F.A.(1961)Comparative Animal Physio
logy.p. 153. W.B.Saunders Company,Philadelphia.
Wells,G.P. (1949) "Respiratory movements of Arenicola marina L.:
intermittent irrågation of the tube, and intermittent aerial
respiration."J.Mar.Biol.Ass.U.K.. 28,447-464.
)"Oxygen uptake as related to body size in
Zeuthen,E. (19!
organisms. Quart.Rev.Biol.. 28,1-12.
18
FIGURES
Figure 1.. Rate of oxygen consumption as dependent on size.
with tentacles
withoutttentaclesso
Figure 2.. Fluctuations in the respiration rate (as mea-
sured in the Warburg apparatus) of one C. spirabrancha.
Figure 3.. The rate of oxygen consumption at decreasing
oxygen tensions,, of two experimental animals.
with tentacles
without tentacles o
Figure 4. Respiration rates of twelve
groups of C.
spirabrancha measured at different temperatures.
150
21°c
O
0.12
0-10
0.O
006
0-04
0.0.
0-10
WET
0-30
020
WEIGHT (GM)
040
050
GRAPH
ML O, / GM/HR
3
0
0-030
0-026
0-022
O-018
0014
0.010
0.006
0
20
%
GRAPH
0 0
SATURATION
60
80
100
O
/WO/O