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The Northwest Atlantic bamboo worm Clymenella torquata, believed to have been imported with commercial oyster culture, was last formally reported from the American Pacific coast more than 30 years ago from a single location. We report here that it is broadly distributed in British Columbia and is now established in Washington. In Samish Bay, Washington, this tubiculous infaunal worm creates a spongy, porous substrate that has proved detrimental to commercial oyster farms by causing the oysters to sink into the sediment and suffocate. Little is known about the ecological or economic impacts of this invasion in the Pacific Northwest.

To address the functional contributions of capillary chaetae in the maldanid polychaete Clymenella torquata, we compared irrigation efficiency and tube structure for animals with intact and trimmed capillary chaetae. We measured pumping rates for worms before and after they were anaesthetized and subjected either to capillary trimming or mock trimming, i.e. handling without trimming. Worms with trimmed chaetae were significantly less effective at moving water through their tubes than those with intact chaetae. There were no significant differences in the ability of control worms to move water within their tubes. No significant changes in rates of peristalsis were observed among experimental or control groups. These data strongly suggest that body musculature and capillary chaetae work in concert to hold worms in position within tubes during peristaltic pumping. When chaetae are shortened, the body musculature must contract to a greater degree, increasing the functional diameter of the worm to achieve the necessary traction with the tube wall, resulting in less efficient irrigation. We also compared the inner diameters of original field tubes to tubes built by control worms or worms after capillary trimming. The inner diameters of new tubes built by worms with shortened chaetae were larger than their original tubes, while those of both control groups were not. One possible explanation is that the chaetae have a sensory role and shortened chaetae send the false message that the nascent tube walls are farther away than they are, the body contracts in compensation and the tube is widened, however this idea has not been tested.

Summary Pterospora demodendrion sp.nov., an acephaline eugregarine (Eugregarinorida, Urosporidae) from the coelom of Axiothella mucosa (Polychaeta, Maldanidae) is described. The gamont averages 277 × 139 μm and possesses 20–36 posterior prolongations. Gametocysts average 412 × 287 μm; without polar funneled openings. Oocysts average 24.4 × 8.4 μm; with aliform wings on the epispore wall and containing a lemon-shaped (16.2 × 7.8 μm) inner capsule. This species is most similar to P. ramificata , though significantly distinct in characteristics of the gamont and gametocyst. Pterospora clymenellae is also reported herein, from the maldanid Clymenella torquata , and shown to lack the epispore wings present in other Pterospora species.

Interactions of two tubicolous, deposit-feeding polychaetes, Clymenella torquata (Leidy) and Polydora ligni Webster, with a filter-feeding bivalve, Gemma gemma (Totten), were examined to test the functional group hypothesis that small, filter-feeding bivalves with large young should attain high densities with tube-builders of any trophic mode because the large young escape predation by tube-builders. The prediction was not supported by Polydora and Gemma, since the two species have not been reported to coexist in high densities in nature. In laboratory experiments, Polydora reduced recruitment and adult survival of Gemma relative to a control. Polydora preyed on juvenile clams and reduced the time which adult clams had their siphons in the feeding position, relative to a control. For Clymenella and Gemma, the functional group hypothesis made the correct prediction (i.e. the two species are reported to coexist in high densities in nature), but for the wrong reason. The size of Gemma's offspring is not related to the intensity of Clymenella predation. Clymenella does not ingest Gemma since the worm does not usually feed from the zone occupied by the clam. In contrast to Polydora, Clymenella did not reduce the time which clams fully extend and open their siphons relative to a control. In laboratory experiments Clymenella increased adult bivalve growth, survival after one year, and recruit size after one month. Clam life history characteristics were similar in the Clymenella and Clymenella plus Polydora treatments because the number of surviving Polydora was reduced by a negative interaction with Clymenella. The tube-builders had different effects on the filter-feeder, Gemma, because these tube-building species differ in feeding position, diet and behavior. Thus, the functional group hypothesis was too general to predict and explain the species interactions and distributions.

Many investigators demonstrate the existence of intra- and interspecific interactions through rigorous statistical hypothesis testing. Statistical significance of an interaction, however, does not necessarily imply that it controls a species population size or distribution. Other analytical methods must be used to make these important determinations. This paper demonstrates one method, with an example, to quantify the demographic importance of statistically significant interactions. In our example, some of the statistically significant interactions with the polychaete Clymenella torquata (Leidy) have large impacts on the population growth rate of the bivalve Gemma gemma (Totten), while others do not. This demonstrates the necessity of distinguishing between statistical significance and demographic importance. In some cases, the demographic importance of the same interaction changes through time because of changes in the bivalve's life history. Interactions affecting juvenile bivalves often have a greater demographic importance than those affecting adults; but this is not always the case.

Cossura soyeri Laubier and Clymenella torquata (Leidy) are newly recorded for the Pacific Ocean. Praxillella praetermissa (Malmgren) is new to the northeast Pacific. Another species of Cossura (unidentifiable) and Maldanella harai (Izuka) are added to the fauna of Washington and British Columbia.Key words: Cossuridae, Maldanidae, new records, Northeast Pacific, Polychaetes

Clymenella torquata (Polychaeta: Maldanidae) traditionally is considered a sub-surface deposit-feeder. We report an undescribed behavior in which the worm uses its posterior segments to collect surface material. Sediment obtained in this manner can be used for tube construction or can be ingested. Laboratory experiments monitoring the effect of Clymenella on sub-surface bacteria suggest that the polychaete can stimulate their growth (‘gardening’). We propose that surface deposit-feeding helps to explain several aspects of the worm's biology (gut contents, dichromatism, and regeneration of posterior segments).

Application a l'analyse quantitative du depot de feces a la surface du sediment par le polychete Clymenella torquata

1. Evidence is presented suggesting the presence of specific head-and tailinhibitors, and of even more specific dorsal-ventral intra-organ tail-inhibitors.2. The tail-inhibitor is shown to be distributed along a posterior-to-anterior gradient.3. Another substance, a "somatic factor," is postulated as existing along an anterior-to-posterior gradient.4. The electrophoretic mobilities of the head-and tail-inhibitors at sea water pH are demonstrated.5. The possibility of bioelectric control of the movements and concentrations of growth- and pattern-specific substances is briefly considered.

The data presented in the present paper and in the two related papers previously published (Sayles, 1940a and b) may be summarized as follows.When oriented with their anterior ends out: (1) implants which include the eighth or more anterior segments will produce definitive head or tail buds with the type dependent to a considerable extent upon which segment of the host is involved; (2) implants including only segment 9 or segments 9-10 will also produce both general types of buds but probably not as frequently as implants from more anterior sources; (3) implants from segment 10 or segments 10-11 occasionally form a head or tail bud; (4) posterior implants which do not include any material from a level anterior to segment 11 very rarely, if ever, produce determinate buds.When oriented with their posterior ends out: (1) anterior implants involving no cord posterior to the ninth segment produce no head or tail buds; (2) implants including only segment 10 or segments 9-10 rarely give rise to these buds; (3) i...

The resistance to high temperatures of two species of intertidal tube-dwelling polychaete worms has been tested to show seasonal and geographic variations. The summer 50% survival temperature at Beaufort, North Carolina, was 42.5 °C for Diopatra cuprea (Bosc) and 40.5 °C for Clymenella torquata (Leidy). Winter 50% survival temperatures for both species at Beaufort were approximately 4.0 C° lower. Both species showed a geographic difference in 50% survival temperature of more than 4.0 C° between North Carolina and Massachusetts in summer. D. cuprea from the Mississippi coast showed a lower survival temperature, probably due to combined temperature and salinity effects. Laboratory acclimation of C. torquata from Beaufort at low temperatures, during summer months, produced experimental results similar to those from winter animals. The seasonal differences in temperature tolerance are phenotypic expressions of a physiological response which can be related to environmental temperature patterns.

A detailed description is given of the anatomy and histology of the blood systems of the maldanid polychaetes Clymenella torquata (Leidy) and Euclymene oerstedi (Claparede) (=Caesicirrus neglectus Arwidsson,1911–12). The systems are similar in many ways to that of the arenicolids. All the longitudinal vessels are contractile. Enlarged cells which contain chloragosomes, glycogen, and iron, are associated with the greater part of the ventral vessel and with the plexus of capillaries surrounding the oesophagus. A gut sinus is associated with the stomach and intestine. Intravasal tissue is present in the dorso-lateral regions of the gut sinus in the tail of Clymenella but not of Euclymene.

Biogenic reworking of marine sediments is described from intertidal deposits in Barnstable Harbor and subtidal sediments of Buzzards Bay, Massachusetts. Reworking activities of three polychaete species were studied in Barnstable Harbor: Clymenella torquata, Pedinarla goiddii, and Amphitrite ornata. Sediment reworking by these tube-dwelling annelids is primarily a vertical and lateral size-sorting process. The selective ingestion and transportation of sand and smaller-sized particles leads to the formation of biogenically graded deposits. Clymenella is estimated to ingest 274 ml. of sediment per worm per year. Pectinaria ingests 400 ml. of sediment per worm per year according to Gordon (1966). The annual reworking rate of Amphitrite remains unknown, but probably exceeds that of Clymenella and Pectinaria. Five stations in Barnstable Harbor were artificially laminated with colored sand horizons to observe biogenic reworking at depth within the sediment. After 2 months, differences in intensity of reworking b...

1. 1. Rhythmic activity has been observed from the polychaetes Clymenella torquata, C. zonalis and C. mucosa. No such activity was observed in Petaloproctus socialis or Branchioasychis americana. 2. 2. The difference in rhythmic activity can be correlated with the ecological niche. Clymenella populations live in anoxic sediments; P. socialis live in coarse sediments. B. americana has filamentous gills. 3. 3. The volume of sediment turned over by C. torquata kept at 26°C was 1 ml/day. 4. 4. The oxyfen consumption of C. torquata is equivalent to 1 cal/day. The food consumed has a caloric value of 10 cal/day.

The coelomocytes of the maldanid polychaetes Clymenella torquata (Leidy) and Euclymene oerstedi (Claparede) (=Caesicirrus neglectus Arwidsson, 1911) appear to be budded off from particular areas of the somatic peritoneum which overlie large blood capillaries in the thorax and trunk, and from more extensive areas of peritoneum at the posterior end of each tail segment. Both species have large numbers of phagocytic coelomocytes which are similar in structure and behaviour to those of some other polychaetes, and appear to have functions both of excretion and nutrition, and to play some part in regeneration. They have a tremendous capacity for ingestion which is shown particularly in late autumn, when they ingest and digest large numbers of disintegrating gametocytes, and after breeding, when they deal similarly with unshed gametes and debris. Clymenella has a second type of coelomocyte which is not phagocytic. This type may contain haemoglobin, but the evidence is not conclusive.

1. Six or fewer anterior segments were exactly replaced.2. Only 2 worms produced buds at cuts posterior to the eleventh segment. Most pieces cut at such levels died relatively soon.3. In the region from the seventh to the eleventh segments there was an increase in deaths, a decrease in ability to produce complete buds, and a marked increase in the number of irregular buds.4. At the ninth to eleventh segments a number of buds were of the usual type but possessed fewer segments than had been removed. Available evidence points to the conclusion that regenerates of this type do not undergo any metamorphosis of segments or any increase in number of segments at the posterior end of the body.5. In several buds a pair of parapodia appeared on the peristomium which is ordinarily asetigerous.6. Eleven cases of heteromorphic or double structures appeared, all confined to cuts at segments 10, 11 or 12. Two of these were double parts of the penistomium. Two were heads with extra structures possessing neither head nor ...

It has been reported that when pieces of nerve cord and neighbor ing tissues from anterior levels of Clyrnenella torquata (region of seg ments 1—7)are inserted into various segments of host of the same species the organization of the resulting buds, which frequently develop, is apparently greatly influenced by the host (Sayles, 1940). The orienta tion of the implant is, however, an important factor. Anterior pieces implanted with their anterior ends in the coelomic cavity and their posterior ends exposed at the surface of the host very rarely produce buds showing definite head or tail characteristics. It was earlier shown (Sayles, 1939) that even though, under some conditions, the nature of the bud might apparently be determined by the host, the new material nevertheless organized so that the exposed part of the implant was in the ventral part of the base of the bud with its original external surface again on the surface. Implants from the posterior region of donors (segments 13—18) have now been used in 514 operations. In 194 of these the posterior ends of the implants were exposed, while in 311 it was the anterior ends which were at the surface. In 9 early cases no attention was paid to the matter of orientation. All of this experimental work was carried on at the Marine Biological Laboratory, Woods Hole, during the summers of 1935—1939, inclusive. The living material was generously provided by the staff of the Supply Department of the Laboratory.

The geographic and ecological distributions of five species of maldanid polychaetes have been characterized. Maximum density of each species occurs in areas where the species does not live sympatrically with other maldanids, even though these areas may not occupy the central portion of its geographic range. A more intensive investigation in Beaufort Harbor, North Carolina, indicates that the sympatry of all five species is accompanied by the reduction of total maldanid density. In the sympatric situation, three species are differentiated ecologically with respect to depth, sediment composition, and substratum utilization. The remaining two species, Clymenella torquata and C. zonalis, are completely sympatric yet undiversified in their utilization of the substratum for tube-building and feeding. The possible importance of an algal pigment, accumulated by C. torquata but not by C. zonalis, is discussed.

SummaryThese data suggest that one may extract from the anal collars of Clymenella torquata an inhibitor which acts within 3 hours, and whose effect lasts at least 8 days. The data furthermore suggest that the inhibitor is not easily metabolized, and that it blocks an initial step in regeneration. The data from the delayed treatment tests suggest that the inhibitor must enter an open wound surface, and that a closed wound is impermeable to inhibitor.

The neuron addition hypothesis predicts that species that add CNS neurons during a particular ontogenetic stage should regenerate ablated somata better than species that add few, if any, neurons to the CNS during that same stage. We report that CNS nerve cells do not regenerate in three species of adult (reproductively competent) leeches (Hirudo medicinalis, Haemopus grande, and Macrobdella decora), which do not increase the number of neurons in any portion of the CNS. Nereis virens, a polychaete that adds CNS neurons to newly forming ganglia in the adult stage, also does not regenerate CNS neurons. Conversely, CNS neurons, including a pair of uniquely identifiable somata, do regenerate in Clymenella torquata, a polychaete that has a constant number of neurons in the adult stage. Hence, the results of our study suggest that several versions of the neuron addition hypothesis cannot predict CNS regenerative abilities in adult annelids. Finally, we report that severed stumps of CNS axons do not degenerate rapidly in Nereis or Clymenella, and that both species can regenerate severed CNS axons presumably by morphologic fusion or physiologic activation of surviving stumps.

THE tubiculous Maldanid polychaetes are among the most abundant infaunal components of intertidal and sub-tidal bottom communities of the North American Atlantic coast. Within their respective ranges the two species Clymenella torquata Leidy and Axiothella mucosa Andrews show a striking dichromatism: populations may be either green or orange. A population inhabiting a particular microgeographic area is always consistent, although the distance over which a colour change occurs may be only a few miles. Continuous intergraduations do not occur. A third closely related species, Euclymene collaris Claparede, does not undergo the colour change; it exists only in the orange form even where it is sympatric with the green forms of the first two. Table 1 lists the colour of populations found at each of seven macrogeographical locations sampled by me.