Respiration in Dodecaceria page 2 B. L. Gasior ABSTRACT Respiratory rates of the common California intertidal Polychaete Dodecaceria fewkesi were measured under different experimental conditions using Warburg constant- volume respirometry. At a constant temperature of 19°C, mean respir- atory rates ranged from 69.08 to 648.61 1 09 / gram worm/ hour (wet weight), depending upon the environmental conditions. No significant difference was found between the rates in and out of their natural tubes in water, whereas in air the res- piratory rate was higher out of their tubes. Respiratory rates in water were significantly higher than those in air under all conditions. Headless worms had a much higher respiratory rate than whole worms. Respiration in Dodecaceria page 3 B. L. Gasior INTRODUCTION Dodecaceria fewkesi was first described from California by Fewkes (1889) under the name Sabella pacifica. Moore (1909, 1923) later reclassified it with regards to specie and genera, and Berkeley and Berkeley (1954) recently elaborated on Moore's description. This specie is distinguished from others in the family Lirratulidae by the presence of setae resembling acicular spines distally spoon shaped, construction of its own calcar- eous tube masses, and its dark green to black color in life (Blake, 1975). Dodecaceria fewkesi lives in asexually repro- ducing clones. It has not yet been experimentally established uhether autotomery precedes regeneration or schizametamery (Dehorne, 1933) occurs. I chose Dodecaceria fewkesi for these experiments because I was particularly interested in respiratory rates under dif- ferent conditions and stresses experienced by an intertidal tube dweller. There appears to be atleast one previous inves- tigation of the influence of the natural tubal environment on respiratory metabolism of Polychaetes (Fox, 1938), and a few authors (Hyman, 1932 and Courtney,1958) have studied the effect of life in glass tubes. Respiration in Dodecaceria page 4 B.L.Gasior ME THODS Worms were collected on April 25, 1976, from rocks at the zero to negative one foot tide level along the boat works beach of Cannery Row, Monterey Bay, California. A chisel and hammer were used to break chunks of the calcareous tube masses from the rocks. The worms were brought to the laboratory and kept in aquaria of running sea water at an average temperature of 12°C at Hopkins Marine Station. In preparation for these experiments I chiselled off smaller chunks of tubes from the colony a minimum of twelve hours before each run. Uhen I needed worms out of their natural tubes I placed the tubes with worms in 100% Mocl, solution for approximately 45 minutes before carefully chopping up the tube chunks into even smaller pieces, and extracting the worms with a pair of fine forceps. I tried to be as gentle as possible, but it is virtually impossible to cut off a portion of the colony without harming at least a few of the inhabitants. Animals in each vessel were weighed after extraction from tubes, and before experiments run out of tubes. The animals were placed on a KIMWIPE for ten minutes before weighing; the weight of worms varied from 0.03 to 2.37 grams/ vessel. After extraction from tubes I counted the number alive, dead, whole, and head¬ less, and weighed the tubular mass. On handling, these worms secrete a pigment from the skin, which has been characterized by R.P. Dales (1963). page 5 Respiration in Dodecaceria B. L. Gasior Ihe duration of all experiments ranged from ten to twelve hours between 0600 and 2400; readings were taken every hour. Ihe vessels were immersed in a constant temperature water bath at 19°C, and shaken at a rate of 50 per minute. Instant ocean was the aqueous medium used throughout the experiments, and the gas phase was air. Respiratory rates were calculated as Al gram wet weighthour. RE SULT All results of these experiments are summarized in lable I. These values for respiratory rate will be compared below for the different experimental conditions used. However, one must first consider the possible contribution of the respir- atory rates of non-worm tubular material to the values given in Experiments I and IV. To examine this question I determined the respiratory rate of the tubular mass in the Warburg vessels in 17 experiments. The resulting rates varied inconsistently, and in some experiments live worms were found in the tubes. According to Berkeley and Berkeley (1954), even one single segment of Dodecaceria may have regenerative powers. Since in breaking up the tubes, a single segment or more of worm was often times left behind, I attributed the small respira- tory rates obtained to this fact. No correction was therefore applied for respiration of the tubes. Respiration in Dodecaceria page 6 B. L. Gasior I. COMPARISON OF RESPIRATORY RATES IN AND OUT OF TUBES OUT DF TUSES IN TUBES P VALUE IN WATER 119.80 9.50 128.39 .o01 IN AIR 69.08 89.84 In water there was no significant difference between respiratory rates in and out of their natural tubes. In air, however, the respiratory rate of worms out of tubes was higher than that of worms in tubes. Perhaps the respiratory rates of worms in and out of tubes in water were not significantly different because there is a layer of water surrounding the animal in its natural tube, and placing it in water out of its tube was not dramatically stressful. I observed that worms out of their tubes in water maintained their natural U-folded position, and did not aggre- gate as they did in air. The significant difference in rates in and out of their tubes in air may be attributed to the left-over water in their tubes as opposed to their semi-dry integument, which was most likely a very stressful situation. Respiration of Dodecaceria page 7 B. L. Gasior II. COMPARISON OF RESPIRATORY RATES IN AIR AND WATER IN AIR IN UATER P VALUE 2.005 69.08 IN TUBES 119.80 OUT OF TUBES 89.84 2.005 128.39 Respiratory rates of worms in water were significantly higher than those in air, both in and out of tubes, The be¬ haviour of Dodecaceria has not been studied in its natural tube, however, perhaps D. fewkesi has the same capabilities as stated for Arenicola and Nereis by Wells (1949). He contends that both Arenicola and Nereis can, when the water level falls below that of the burrow openings, resort to aerial respira- tion by trapping bubbles in the water which remains in the burrow. This ability could be important for intertidal species experiencing long exposure, both for obtaining oxygen to main- tain the standard metabolic rate, and in preventing CO, build- up, but there are no experimental data. De-tubed worms placed in air, assumingly, are under great stress because they are not receiving a constant fresh supply of sea water. The slight drying of their integument may be enough to initiate decreased respiration. A decrease in activity may also explain the de- creased respiration, but it is yet unknown whether activity is substantially decreased when these worms are exposed at low tide. The comparison of respiratory rates of whole and headless worms in air and water will be found in the following section. Respiration in Dodecaceria page 8 B. L. Gasior III. COMPARISON OF RESPIRATORY RATES OF WHOLE UORMS WITH HEADLESS UORMS WHOLE HEADLESS P VALUE 96.29 IN AIR .002 137.02 123.94 o01 IN UATER 648.61 P VALUE .001 .001 A. IN UATER It is interesting to note that the respiratory rate of whole worms in water is not significantly different from that of worms out of their tubes in water. However, headless worms in water had a respiratory rate 5 times as high as whole worms under the same conditions. I feel the remarkable significant difference noted in the rates under these conditions can be attributed, in large, to regenerative properties of this specie. The standard metabolism during growth is known to be appreciably higher than during adulthood (Hemmingsen, 1950 ). Much research has been done on the role of a crown or anterior branchial filaments in respiration.(Zoond, 1931 and Wells, 1949a, 1952 and Courtney, 1958 ). Wells concluded that the localisation of oxygen uptake depends more on behaviour than anatomy (1952). Respiration in Dodecaceria page 9 B. L. Gasior B. IN AIR The significantly lower respiratory rate found for whole worms as opposed to headless worms in air may be due to the innate fact that whole worms are not regenerating. Being exposed in air is a stressful enough situation to lead to a decreased respiratory rate. C. UHOLE UORMS In comparing the respiratory rates of whole worms in air and water one sees that they are in accord with those out of tubes in air and water. The lower respiratory rate in air can most likely be accounted for by a decrease in activity. D. HEADLESS UORMS The respiratory rate of headless worms in water is seen to be slightly more than 5 times their respiratory rate in aif. I believe they are maximizing efficiency of metabolism while in water. There are most likely some essential elements in water for regeneration, respiration, and other metabolic functions that are missing in air. Perhaps their activity is always highest while immersed in water, in compensation for the time spent exposed during low tides. It would be to any intertidal animal's advantage to function in this manner. page 10 Respiration in Dodecaceria B. L. Gasior DISCUSSION Bounhiol found respiratory rates of Cirratulids small compared with values obtained for active errant forms of Nereis and Nephtys, and for Arenicola, Amphitrite, and Sabella pavonina. He attributed this low metabolic rate to the small amount of muscular activity, but his results must be interpreted with caution because of the inadequacy of methods for quanti¬ tative work in 1903. Courtney (1958) stated that the intertidal Cirratulid Polychaetes Audouinia tentaculata, Lirratulus cir- ratus, and Dodecaceria concharnum do not irrigate their burrows. Both food and oxygen are obtained from the surface of the habitat by means of branchial and tentacular filaments. Many conflicting data have been compiled on respirometry of various other Polychastous Annelids. Ewer & Fox (1940) con¬ tend that 0 consumption of Sabella varies with 0, tension, while Hyman (1932) holds that the fall in 0, consumption with time in Nereis virens is largely conditioned by some other factor(s) than the fall in 0, content of its environment. The worms showed a relatively constant respiratory rate over the duration of each of my experiments. This trend is in accor¬ dance with the findings of Dolk & Paauw (1929). They found that earthwormscare efficient breathers, respiring at a constant rate down to 1/8 the 0, concentration of air. Fox (1938) showed that O, consumption of S. spallanzanii declined progressively after the removal of the worm from its Respiration in Dodecaceria page 11 B. L. Gasior hatural tube. The decline of S. pavonina was shown to be negligible during the first 5 hours of de-tubing. Hyman (1932) , with respect to Nereis virens, showed that O, uptake was higher in worms unenclosed than worms enclosed in glass tubes. My results are not in accord with these findings for a significantly lower value was not found for worms out of their tubes. CONCLUSTON It seems as though the intertidal specie of Dodecaceria fewkesi can adjust its respiratory rates to meet different stresses. My experimental results seem more consistent with those of the earthworm (Dolk & Paauw, 1929). Much more work needs to be done on the respiratory rates of invertebrates, for there seems to be no uniformity in the results relating 09 consump- tion to 0, tension or habitat. As Hemmingsen suggests (1950) and Courtney (1958) states, "...it is clear that among the Polychaetes there is considerable variation in the absolute values of the respiratory rates, owing to diversity of way of life...' Respiration in Dodecaceria page 12 B. L. Gasior ACKNOULEDGEME I wish to thank the faculty and staff at Hopkins Marine Station, and especially thank Dr. Fred Fuhrman for his invaluable aid and loyalty as an adviser. Respiration in Dodecaceria page 13 B. L. Gasior REFERENCES Berkeley, E. and C. 1954. Notes on the Life History of the Polychaete Dodecaceria fewkesi (nom. n.). Fish. Res. Bd. Canada, 11: 920 - 334. Blake, J. A. 1975. Phylum Annelida: Class Polychaeta. pp.151- 243. Chapter in Light's Manual. Intertidal Invertebrates of the Central California Coast. Smith, R. I. and Carlton, J. T. (eds). Univ. Calif. Press. Bounhiol, J. 1903. Recherches biologiques experimentales sur la respiration des annelides polychetes. Ann. Sci. nat., Paris. ser 8, 16: 1 - 131. Lourtney, W. A. M. 1958. Certain aspects of the Biology of the Lirratulid Polychaetes. (phD thesis) Univ. of London. Dales,R. P. 1963. Pigments in the skins of the Polychaetes Arenicola, Abarenicola, Dodecaceria, and Halla. Lomp. Biochem. Physiol., 8 : 99 - 108. Dehorne, A. 1933. La schizometamerie et les segments tetra- gemmes de Dodecaceria aulleryi, N. Sp. Bull. biol. 67: 298 . 520. Dolk, H. E.,and Paauw, F. van der. 1929. Die Leistungen des Hamoglobins beim Regenwurm. Zeitsch. f. vergleich. Physiol., 10, S. 324. Ewer D. W. and Fox, H. M. 1940. On the function of chlorocruorin, Proc. Roy. Soc., London. B 129 : 137 - 153. Feukes, J. N. 1889. New invertebrates from the coast of Cali- fornia. Bull. Essex Inst., Boston. 21: 99 - 146. H. M. 1938. On the blood circulation and metabolism of Fox, Sabellids. Proc. roy. Soc., London. B, 125 : 554 - 69. Hemmingsen, A. M. 1950. The relation of standard (basal) energy metabolism to total fresh weight of living organisms. Rep. Steno Hosp., Copenh., 4 : 7 - 58. tension to 0 consumption Hyman, L. H. 1932. Relation of 0. in Nereis virens. J. Exptl. Zool. 61 : 209. Moore, J. P. 1909. Polycheatous annelids from Monterey Bay and San Diego, California. Proc. Acad. Nat. Sci. Philadelphia. 61 : 235 - 294. --------1923. The Polychaetous annelids dredged by the U.S.S. " Albatross " off the Coast of Southern Ca. in 1904. 4. Spionidae to Sabellariidae. Ibid., 75: 179 - 259. Respiration in Dodecacer page 14 B. L. Gasior Wells, G. P. 1949. Respiratory movements of Arenicola marin: L. : intermittent irrigation of the tube and intermittent aerial respiration. J. Mar. Biol. Ass. U. K. 28: 447 - 64. Zoond, A. 1931. Studies in the Localisation of Respiratory Exchange in invertebrates. J. Exptl. Biol. 8: 258 - 62. 1/15 mm Ve FIGURE I t . S ket V in . a DODECACERIA FEWKESI 650 500 500 400 300 5 200 100 —— 9 - IN AIR 5 IN WATE FIGURE II Figure I : Anterior portion of an Intertidal Dodecaceria fewkesi as drawn from Light's Manual Figure II : Mean Respiratory Rates of Intertidal Dodecaceria fewkesi under different experimental conditions TABLE I EXPERIMENTAL CONDITIONS I. worms in tubes in air II. worms out of tubes in air III. whole worms out o tubes in air worms in tubes in water IV. whole worms out of tubes in water VI. worms out of tubes in water VII. headless worms out of tubes in air headless worms out of VIII. tubes in water N* 11 13 13 14 MEAN RESPIRATORY RATE** Al 0/m worm/hr 69.08 + 14.74 89.84 + 20.13 96.29 + 16.80 119.80 + 37.92 123.94 + 11.90 128.39 + 40.17 137.02 + 16.71 648.61 + 148.94 Of Intertidal Dodecaceria Table I : Mean Respiratory Rates under different Experimental Conditions * N = number of determinations Legend: ** value standard deviation