Commensal symbiosis between agglutinated polychaetes and sulfate‐reducing bacteria

Pendant bioconstructions occur within submerged caves in the Plemmirio Marine Protected Area in SE Sicily, Italy. These rigid structures, here termed biostalactites, were synsedimentarily lithified by clotted‐peloidal microbial carbonate that has a high bacterial lipid biomarker content with abundant compounds derived from sulfate‐reducing bacteria. The main framework builders are polychaete serpulid worms, mainly Protula with subordinate Semivermilia and Josephella. These polychaetes have lamellar and/or fibrillar wall structure. In contrast, small agglutinated terebellid tubes, which are a minor component of the biostalactites, are discontinuous and irregular with a peloidal micritic microfabric. The peloids, formed by bacterial sulfate reduction, appear to have been utilized by terebellids to construct tubes in an environment where other particulate sediment is scarce. We suggest that the bacteria obtained food from the worms in the form of fecal material and/or from the decaying tissue of surrounding organisms and that the worms obtained peloidal micrite with which to construct their tubes, either as grains and/or as tube encompassing biofilm. Peloidal worm tubes have rarely been reported in the recent but closely resemble examples in the geological record that extend back at least to the early Carboniferous. This suggests a long‐lived commensal relationship between some polychaete worms and heterotrophic, especially sulfate‐reducing, bacteria.     

Mineralization of Alvinella polychaete tubes at hydrothermal vents

Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep‐sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine‐scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs.     

Mud mounds: A polygenetic spectrum of fine-grained carbonate buildups

Summary This research report contains nine case studies (part II to X) dealing with Palaeozoic and Mesozoic mud mounds, microbial reefs, and modern zones of active micrite production, and two parts (I and XI) summarizing the major questions and results. The formation of different types ofin situ formed micrites (automicrites) in close association with siliceous sponges is documented in Devonian, Carboniferous, Triassic, Jurassic and Cretaceous mounds and suggests a common origin with a modern facies found within reef caves. Processes involved in the formation of autochthonous micrites comprise: (i) calcifying mucus enriched in Asp and Glu, this type presumably is linked to the formation of stromatolites, thrombolites and massive fabrics; (ii) protein-rich substances within confined spaces (e.g. microcavities) result in peloidal pockets, peloidal coatings and peloidal stromatolites, and (iii) decay of sponge soft tissues, presumably enriched with symbiotic bacteria, lead to the micropeloidal preservation of parts of former sponge bodies. As a consequence, there is strong evidence that the primary production of micrite in place represents the initial cause for buildup development. The mode of precipitation corresponds to biologically-induced, matrix-mediated mineralization which results in high-Mg-calcites, isotopically balanced with inorganic cements or equilibrium skeletal carbonates, respectively. If distinct automicritic fabrics are absent, the source or origin of micrite remains questionable. However, the co-occurring identifiable components are inadequate, by quantity and physiology, to explain the enhanced accumulation of fine-grained calcium carbonate. The stromatolite reefs from the Permian Zechstein Basin are regarded as reminiscent of ancestral (Precambrian) reef facies, considered the precursor of automicrite/sponge buildups. Automicrite/sponge buildups represent the basic Phanerozoic reef type. Analogous facies are still present within modern cryptic reef habitats, where the biocalcifying carbonate factory is restricted in space.     

Feinstruktur der Pollenschläuche im Griffel vonPetunia

Summary From electron microscopic observation of transverse sections through the style ofPetunia it was possible to show that the pollen tubes grow within the compact matrix of the middle lamellae of the transmitting tissue. This it does enzymatically by dissolving a pipelike path in front of the tube tip. From the fine structure of the cytoplasm and the organelle content, the cells of the tubes and of the transmitting tissue can be distinguished. Differences in the fine structure of the cytoplasm and the wall between inhibited (incompatible) and normal growing (compatible) pollen tubes can be demonstratedin situ. This is discussed in terms of localisation of the incompatibility reaction on the surface of the inhibited pollen tubes. The interpretation is in agreement with genetical and biochemical observations elsewhere.     

Immunocytochemical and chemical analyses of Golgi vesicles isolated from the germinated pollen ofCamellia japonica

As a first step towards studying the biochemical relationship between Golgi vesicles (GVs) and tube wall components, isolation of GVs from the growing pollen tubes ofCamellia japonica was attempted using a centrifugation method with mannitol. The isolated GV was identified ultrastructurally and immunocytochemically. The main components of the GV were proteins and carbohydrates. The main monosaccharides of GV polysaccharides were galactose, arabinose and uronic acid, and pectins and arabinogalactan proteins also were detected immunochemically. An antiserum against the isolated GVs reacted with the outer layer of the pollen tube wall and the intine layers of the grain wall as well as thein situ GVs in the pollen tube and the grain cytoplasm. We have thus successfully isolated GVs and shown that they contain pectic substances and arabinogalactan proteins which contribute to formation of the pollen tube primary wall.     

The wall ofPinus sylvestris L. pollen tubes

Summary The wall ofPinus sylvestris pollen and pollen tubes was studied by electron microscopy after both rapid-freeze fixation and freeze-substitution (RF-FS) and chemical fixation. Fluorescent probes and antibodies (JIM7 and JIM5) were used to study the distribution of esterified pectin, acidic pectin and callose. The wall texture was studied on shadow-casted whole mounts of pollen tubes after extraction of the wall matrix. The results were compared to current data of angiosperms. TheP. sylvestris pollen wall consists of a sculptured and a nonsculptured exine. The intine consists of a striated outer layer, that stretches partly over the pollen tube wall at the germination side, and a striated inner layer, which is continuous with the pollen tube wall and is likely to be partly deposited after germination. Variable amounts of callose are present in the entire intine. No esterified pectin is detected in the intine and acidic pectin is present in the outer intine layer only. The wall of the antheridial cell contains callose, but no pectin is detectable. The wall between antheridial and tube cell contains numerous plasmodesmata and is bordered by coated pits, indicating intensive communication with the tube cell. Callose and esterified pectin are present in the tip and the younger parts of the pollen tubes, but both ultimately disappear from the tube. Sometimes traces in the form of bands remain present. No acidic pectin is detected in either tip or tube. The wall of the pollen tube tip has a homogenous appearance, but gradually attains a fibrillar character at aging, perhaps because of the disappearance of callose and pectin. No secondary wall formation or callose lining can be seen wilh the electron microscope. The densily of the cellulose microfibrils (CMF) is much lower in the tip than in the tube. Both show CMF in all but axial and nontransverse orientations. In conclusion,P. sylvestris and angiosperm pollen tubes share the presence of esterified pectin in the tip, the oblique orientations of the CMF, and the gradual differentiation of the pollen tube wall, indicating a possible relation to tip growth. The presence of acidic pectin and the deposition of a secondary-wall or callose layer in angiosperms but not inP. sylvestris indicales that these characteristics are not related to tip growth, but probably represent adaptations to the fast and intrastylar growth of angiosperms.Abbreviations CMF cellulose microfibrils - II inner intine - NE nonsculptured exine - OI outer intine - RF-FS rapid-freeze fixation freeze-substitution - SE sculptured exine - SER smooth endoplasmic reliculum - SV secretory vesicles     

The morphology and anatomy of the vestimentiferan worm <Emphasis Type="Italic">Oasisia alvinae</Emphasis> Jones, 1985 (Annelida: Siboglinidae). I. External morphology,obturaculae and tentacles

This study describes the tube structure, external morphology, and histological organization of the obturacula and tentacles of the small hydrothermal-vent vestimentiferan worm Oasisia alvinae. The tubes are considerably twisted and bear collars, thus suggesting a step-like growth of the worm. The total length of the studied specimens is 32–41 mm. The trunk region comprises 75% of the total body length and is differentiated into a broadened forepart and a narrowed posterior part. The ratio between the lengths of the obturacular and vestimental regions is 0.62–0.63. The examined specimens of O. alvinae have 13 to 17 pairs of tentacular lamellae; the total number of tentacles is about 550. The muscular bands in the obturacula of O. alvinae lie in the parafrontal planes. Polymorphism occurs in the number and arrangement of the denticles of the opistosomal chaetae in O. alvinae.     

ON THE TUBE ULTRASTRUCTURE AND ORIGIN OF CALCIFICATION IN SABELLIDS (ANNELIDA, POLYCHAETA)

Abstract:  Tube ultrastructure of Jurassic and Cretaceous Glomerula is very similar to that of Recent Calcisabella , supporting the synonymy of these genera and the early Mesozoic origin of calcification in sabellids. Tube structure of serpulids differs from that of Glomerula ; calcareous tubes probably evolved convergently within Sabellida. The tube wall in Recent Glomerula piloseta is composed of subparallel lamellae of aragonitic, irregular spherulitic prisms in the inner layer, and spherulites in the outer layer. Calcified lamellae are separated by organic films of different thickness. The structure of the internal tube layer in Glomerula piloseta , and the structure of entire wall in fossil Glomerula , are similar to the tube structure of Dodecaceria (Polychaeta, Cirratulidae). The irregular spherulitic prisms of Glomerula are similar to those found in the external layer of Hydroides dianthus and the internal layer of Spiraserpula caribensis .     

Microfacies and paleoenvironment of<Emphasis Type="Italic">Donezella</Emphasis> accumulations across an upper Carboniferous high-rising carbonate platform (Austurias,NW Spain)

Summary Donezella is a problematic organism that during the mid-Carboniferous (latest Serpukhovian to Moscovian) characterized carbonate depositional systems in Europe, North Africa, Russia, Kazakhstan, and North America. ThoughDonezella is generally included in the green calcareous algae, it has been attributed to different systematic groups and its classification and paleoecology still remain controversial. This work focuses on the distribution ofDonezella across a carbonate platform (Sierra de Cuera) of Upper Carboniferous (lower Bashkirian-lower Moscovian) age located in the Cantabrian Mountains (Asturias, NW Spain). Sierra de Cuera exhibits a well-exposed cross-section from the horizontal platform through a steep slope (30°) to the basin floor. This unique feature allows reliable estimates of paleo-water depth and distance from the platform margin.Donezella specimens are interpreted asin situ when they form a network supporting cement-filled primary cavities and the ramified skeletons are surrounded by micrite coatings, often with a peloidal fabric, or by early marine cement. In the platform interior,Donezella is associated with phylloid algae and occurs in mud-rich low-relief bioherms. Towards the platform margin, massive units of boundstone are characterized by clotted peloidal micrite and radial fibrous cement-filled primary cavities. They containDonezella and a diverse fossil assemblage of calcareous algae, bryozoans, and foraminifers.Donezella's delicate network appears fortified by thein situ precipitation of peloidal micrite. On the upper slopein situ precipitated peloidal micrite, abundant radial fibrous cement, and fenestellid bryozoans are the major components of the boundstone facies, along withDonezella and a eskeletal community similar to the outer platform one. On the slope,in situ Donezella were observed down to paleowater depths up to 200 m. Sedimentologic, petrographic, and microfacies analysis ofDonezella accumulations in the different facies belts of Sierra de Cuera strongly suggest that this problematic organism was able to thrive over a large depth range, in low-energy but also in moderately agitated environments or in settings with temporary increase in current action, and in organic, physical-chemical and oceanographic conditions that enhanced the precipitation of peloidal micrite. The interval of water depth inferred from the well-exposed slope geometry of Sierra de Cuera suggests that eitherDonezella might not have belonged to the green calcareous algae or, alternatively, this depositional system was influenced by particular paleo-oceanographic conditions that extended the euphotic zone below the average depth. The morphology ofDonezella's skeleton and its sedimentological occurrences are not exclusively indicative of an affinity with Chlorophyta. Therefore, it is suggested thatDonezella should be considered as amicroproblematicum organism. The data presented in this study contribute to the inter-pretation of comparableDonezella accumulations in carbonate depositional systems where limited outcrop exposures do not allow correct evaluation of the geometry and facies distribution.     

Influence of phototropic response of spore germ tubes on infection process inColletotrichum lagenarium andBipolaris oryzae

The germ tubes ofColletotrichum lagenarium showed negative phototropism to UV-blue (300–520 nm) and far-red (>700 nm) regions with maximum in the near ultraviolet (NUV) region, while monochromatic radiations of 575–700 nm (yellow-red region) induced positive phototropism with maximum in the red region. Green light (520–575 nm) was ineffective. Negative phototropism-inducing wavelength regions inhibited germ tube growth and positive phototropism-inducing wavelength regions promoted it significantly.Bipolaris oryzae did not show any phototropic response and light did not affect the germ tube growth. These results indicate that the lens effect, in combination with the light growth reaction and light growth inhibition, is the mechanism of the phototropism of germ tubes ofC. lagenarium. NUV radiation, which induced negative phototropism ofC. lagenarium, promoted appressorium formation, while red light, which induced positive phototropism, suppressed it significantly. In the case ofB. oryzae, light did not affect the infection structure formation. These results indicate that negative phototropism of germ tubes ofC. lagenarium favors the infection process by facilitating the contact of the tips of germ tubes with the host surface, while positive phototropism has the opposite effect.     

Distribution and abundance of a nemertean egg predator ( Carcinonemertes sp.) on a leucosiid crab,Randallia ornata

The purple globe crab, Randallia ornata (Randall, 1839) (Decapoda: Leucosiidae) is a common crustacean found on sandy beaches from Northern California to Baja California, Mexico. An undescribed species of Carcinonemertes, which shares biological features with a partially described worm from Tasmania was recovered from R. ornata. The worm reaches 10 mm in length and secretes a sturdy tube with a distinctive spiral shape. The total prevalence of the worm on R. ornatawas 70% (85% for ovigerous female crabs, 67% for post-ovigerous female crabs, and 45% for male crabs). Intensities reached 32 worms per crab. Adult worms were found in crab egg masses, regressed adults were recovered from under the abdomen of post-ovigerous females, and encysted juveniles were found on the gill lamellae of non-ovigerous female crabs and occasionally from the gill lamellae of male crabs.     

Microbial contribution to deposition of upper carboniferous and lower Permian seamount-top carbonates,Akiyoshi, Japan

Summary Microbial organisms significantly contributed to the accumulation of shallow-marine carbonates in an open-ocean realm of the Panthalassan Ocean during Late Carboniferous-Early Permian time. The Jigokudai plateau in the northern part of the Akiyoshidai Plateau is the study area, where the limestone of the Upper Carboniferous Kasimovian Stage to the Lower Permian Artinskian Stage is well exposed. The fusulinid biostratigraphy as well as top-bottom geopetal fabrics revealed that the rocks of the study area are overturned. The thickness of this succession is approximated to 150 m. The succession is lithologically divided into the Lower Jigokudai and Upper Jigokudai formations. The lime-stones of these formations were deposited in a lagoonal setting. The Lower Jigokudai formation (95 m thick: Kasimovian to Asselian) is characterized by sand shoal facies represented by crinoid-Tubiphytes-fusulinid peloidal pack/grainstones and oolitic grainstones. Phylloid algal grain/packstones and microbial boundstones subordinately crop out. The Upper Jigokudai Formation (55 m thick: Sakmarian to Artinskian) is characterized by shoal and tidal flat facies represented by mollusk-fusulinid peloidal grain/rudstones, and peloidal grain/rudstones and peloidal lime-mudstones, respectively. Laterally discontinuous microbial bound-stones occur intercalated in mollusk-fusulinid peloidal grain/rudstones. This formation contains pendant and meniscus cements, and flat-pebble breccia indicative of an intertidal deposition and subaerial exposure. Various types of boundstone and organosedimentary structures constructed mainly by filamentous cyanobacteria,Tubiphytes obscurus tubular microproblematicum A, and other microproblematica were recognized. Significant facies types are (1) filamentous cyanobacteria-microproblematicum A bind/framestones, (2)Tubiphytes obscurus bindstones, (3) stromatolitic bindstones, (4) microbial laminites, (5) microbially linked structures, (6) oncoids, (7) microproblematica B-C framestones. The calcimicrobes, combined with synsedimentary cementation, formed small-scale and low-relief mounds of these facies, and greatly contributed to the deposition of the Kasimovian to Artinskian Panthalassan buildup.     

Ultrastructural immunolocalization of periodic pectin depositions in the cell wall ofNicotiana tabacum pollen tubes

Summary The monoclonal antibody (MAb) JIM5, marking acidic pectins, was used to localize ultrastructurally pectin molecules in the pollen tube wall ofNicotiana tabacum. Longitudinal sections of LR-White embedded pollen tubes were exposed to antibody treatment; accumulations of pectins were identified by counting the density of the gold particles representing the pectin epitopes along the pollen tube wall. Significant accumulations of gold grains were marked and the distances between them were measured. In many pollen tubes a more or less regular distribution of the accumulations was observed along the tube indicating a periodical deposition of pectin. The distances between the accumulations were 4–6 m. Most of the label was found in the inner part of the outer layer of the bilayered cell wall. These findings correspond to and confirm the earlier observation by our group reporting ring-shaped periodical deposits in pollen tubes after immunofluorescence labelling with the MAb JIM5 under the confocal laser scanning microscope.Abbreviations Ab antibody - MAb monoclonal antibody     

Structural aspects of in vitro pollen tube growth and micropylar penetration inGasteria verrucosa (Mill.) H. Duval andLilium longiflorum Thunb.

Summary In vitro penetration of the micropyle of freshly isolatedGasteria verrucosa ovules by pollen tube was monitored on agar medium. 40–60% of the micropyles were penetrated, comparable with in vivo penetration percentages. When germinated on agar,Gasteria pollen tube elongation lasts for up to 8 h while plasma streaming continues for about 20–24 h. The generative cell divides between 7 and 20 h after germination, and after 20 h the pollen tube arrives at one of the synergids. The sperm cells arrive after 22 h. The whole process takes more time in vitro than in vivo. In fast growing pollen tubes, a pulsed telescope-like growth pattern of tube elongation is observed. The formation of pollen tube wall material precedes tube elongation and probably prevents regular enlargement of the pollen tube tip-zone. Rapid stretching of the new pollen tube wall material follows, probably due to gradually increased osmotic pressure and the use of lateral wall material below the tip. The stretching ceases when the supplies of plasma membrane and excretable wall material are exhausted. Multiple pollen tube penetration of the micropyle occurs in vitro as it does in vivo. Most pollen tube growth ceases within the micropyle but, if it continues, the pollen tubes curl. Inside the micropyle the pollen tube shows haustorial growth. At the ultrastructural level, the wall thickening of in vitro pollen tubes is quite similar to that in vivo. Before transfer of pollen tube cytoplasm a small tube penetrates one of the synergids. Sperm nuclei with condensed chromatin are observed in the pollen tube and the synergid. In vivo prometaphase nuclei are found in the most chalazal part of a synergid, against the egg cell nucleus and nucleus of the central cell at a later stage. Using media forLilium ovule culture,Gasteria ovules were kept alive for at least 6 weeks. Swelling of the ovule depends on pollen tube penetration. The conditions for fertilization to occur after in vitro ovular pollination seem to be present.     

Characterization of fibrous compound of Golgi vesicles in tapetal cells ofDelphinium

Summary It was shown that Golgi structures abundantly appearing in tapetal cells ofDelphinium Ajacis L. developing anthers, prior to meiocytes meiosis, show a fine fibrous material within their vesicles. At the time of the formation of tapetal cell wall this fibrous component, released by an exocytotic process, is incorporated into the cell wall. The membrane of dictyosomes derived vesicles participates in the development of plasma membrane. Fibrous material appears to be morphologically similar to the fibrils of tapetal cell wall; this cell wall gives a positive reaction for cellulose and pectins, as visible in the light microscope. Moreover, the fibrous and pectinase resistant compound of dictyosomes derived vesicles and the fibrils of cell wall disappear partly after cellulase digestion which proves their cellulosic character. On the other hand pectinase treatment as well as ruthenium red staining suggest associated with cellulose pectins within Golgi vesicles.     

Chaetae and mechanical function: tools no Metazoan class should be without

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.     

The feeding ecology of Axiothella rubrocincta (Johnson) (Polychaeta: Maldanidae)

The feeding ecology of Axiothella rubrocincta (Johnson) from Tomales Bay, California, is described. This worm inhabits a U-shaped tube of agglutinated sand grains and mucus. Morphological adaptations such as nuchal and anal plaques prevent the tube from becoming clogged. Foreign debris entering the tube is either consumed or incorporated into the tube wall. The proboscis and notosetae are probably used to clean the tube wall. A. rubrocincta combines feeding and burrowing activities to form the funnel and complete the tube: it does not ingest sediment while burrowing. Organic matter deposited into the funnel is buried there by sand slides originating at the rim of the funnel. The concentration of organic matter within the funnel is significantly higher than for non-funnel sediments. A. rubrocincta consumes food from the upper 2 cm of the substratum and is 4.6% efficient as a depositfeeder. It also feeds within the funnel and can ingest large quantities of food. This feeding process is described. A. rubrocincta irrigates its tube at a rate of 5.1 ml sea water/g/h while feeding, and briefly reverses this current to a rate of 0.1 ml/g/h when defaecating. The rhythmic activity patterns are integrated: the mean defaecation and inverse pumping time is 14.4 min at 15 ± 1 C.     

ULTRASTRUCTURE OF PORPHYRIDIUM AERUGINEUM A BLUE-GREEN COLORED RHODOPHYTAN1,2,3.

The ulstrastructural study on Porphyridium aerugineum showed vesicles in the peripheral cytoplasm which contain fibrous material similar in appearance to the cell sheath. In most respects the morphology of P. aerugineum, a freshwater form, is very similar to that of P. cruenturn, a marine species. However, there is a marked difference in the shape of the phycobilisomes which are attached to the chloroplast lamellae. In P. cruentum the phycobilisomes are always spherical or oblate, whereas in P. aerugineum they are disk shaped. The possibility is considered that the shape of the phycobilisomes may be determined by the phycoerythrin and phycocyanin content.     

Broad-range effects of ionophore X-537A on pollen tubes of Lilium longiflorum

The effects of the broad-range cationophore X-537A on pollen tubes of Lilium longiflorum were investigated, using both light and electron microscopy. Pollen tube growth is completely inhibited within 30 min after the application of 5·10^-5 M ionophore X-537A; cytoplasmic streaming is stopped only after 60 min of ionophore treatment. Ultrastructurally, X-537A effects are a vacuolation of Golgi cisternae and a general vacuolation. The wall is thickened at the very tip. Coated vesicles and coated regions are enriched close to and at the plasma membrane. The results indicate that pollen tube tip growth needs a specific ion distribution.Abbreviations CTC chlorotetracycline - DMSO dimethylsulfoxide     

Textures and traction: how tube‐dwelling polychaetes get a leg up

By controlling the traction between its body and the tube wall, a tube‐dwelling polychaete can move efficiently from one end of its tube to the other, brace its body during normal functions (e.g., ventilation and feeding), and anchor within its tube avoiding removal by predators. To examine the potential physical interaction between worms and the tubes they live in, scanning electron microscopy was used to reveal and quantify the morphology of worm bodies and the tubes they produce for species representing 13 families of tube‐dwelling polychaetes. In the tubes of most species there were macroscopic or nearly macroscopic (~10 μm–1 mm) bumps or ridges that protruded slightly into the lumen of the tube; these could provide purchase as a worm moves or anchors. At this scale (~10 μm‐1 mm), the surfaces of the chaetal heads that interact with the tube wall were typically small enough to fit within spaces between these bumps (created by the inward projection of exogenous materials incorporated into the tube wall) or ridges (made by secretions on the interior surface of the tube). At a finer scale (0.01–10 μm), there was a second overlap in size, usually between the dentition on the surfaces of chaetae that interact with the tube walls and the texture provided by the secreted strands or microscopic inclusions of the inner linings. These linings had a surprising diversity of micro‐textures. The most common micro‐texture was a “fabric” of secreted threads, but there were also orderly micro‐ridges, wrinkles, and rugose surfaces provided by microorganisms incorporated into the inner tube lining. Understanding the fine structures of tubes in conjunction with the morphologies of the worms that build them gives insight into how tubes are constructed and how worms live within them.