Sponge Morphology Research Articles

Environmental Flow Regimes for Dysidea avara Sponges

The aim of our research is to design tank systems to culture Dysidea avara for the production of avarol. Flow information was needed to design culture tanks suitable for effective production. Water flow regimes were characterized over a 1-year period for a shallow rocky sublittoral environment in the Northwestern Mediterranean where D. avara sponges are particularly abundant. Three-dimensional Doppler current velocities at 8-10-m depths ranged from 5 to 15 cm/s over most seasons, occasionally spiking to 30-66 cm/s. A thermistor flow sensor was used to map flow fields in close proximity ( approximately 2 cm) to individual sponges at 4.5-, 8.8-, and 14.3-m depths. These "proximal flows" averaged 1.6 cm/s in calm seas and 5.9 cm/s during a storm, when the highest proximal flow (32.9 cm/s) was recorded next to a sponge at the shallowest station. Proximal flows diminished exponentially with depth, averaging 2.6 cm/s +/- 0.15 SE over the entire study. Flow visualization studies showed that oscillatory flow (0.20-0.33 Hz) was the most common regime around individual sponges. Sponges at the 4.5-m site maintained a compact morphology with large oscula year-around despite only seasonally high flows. Sponges at 8.8 m were more erect with large oscula on tall protuberances. At the lowest-flow 14.3-m site, sponges were more branched and heavily conulated, with small oscula. The relationship between sponge morphology and ambient flow regime is discussed.

Palaeophragmodictya spinosa sp. nov., a bilateral benthic organism from the Vendian of the Southeastern White Sea Region

A fossil organism, Palaeophragmodictya Gehling et Rigby, 1996, previously classified within sponges, is found for the first time in the Vendian of the Arkhangelsk Region. Based on the new finds, Palaeophragmodictya is interpreted as an attachment disc of a problematic animal with combined coelenterate and sponge morphology. Typical and unique preservational forms from the same bedding plane are described. Three-dimensional fossils are preserved as flat impressions at random horizontal levels. Bilateral symmetry discovered in the ontogeny of Palaeophragmodictya spinosa sp. nov. supports the hypothesis of initial bilaterality of Cnidaria.

Gold Sponges Prepared via Hydrothermally Activated Self-Assembly of Au Nanoparticles

In this work, we describe a self-assembly approach for generation of nanostructured Au sponges with Au nanoparticles as starting building blocks. It is found that the hydrothermal condition is essential to detach surfactants and thus trigger the self-assembly of Au nanoparticles. The resultant Au sponges are comprised of finely branched nanowires whose diameters can be selected in the range of 15−150 nm. The sponge morphology can be further controlled by manipulating surfactant population, concentration of metallic nanoparticles, amount and type of alcohol solvent, process temperature and time, etc. In principle, this template-free approach can also be extended to large-scale three-dimensional organizations of other surfactant-capped transition/noble metal nanoparticles.

On the evolution of morphology of zirconium sponge during reduction and distillation

High purity zirconium metal is produced by magnesio-thermic reduction of zirconium tetrachloride followed by vacuum distillation. The reduction process is carried out in a batch giving metal sponge and magnesium chloride in the reduced mass. The sponge is purified to using by vacuum distillation. The morphology of the sponge formed during the reduction and its influence on further processing has significant importance. In the present study, a detailed investigation involving evolution of the morphology of sponge particles and its implication during the vacuum distillation was carried out. The study of the microstructure was done using scanning electron microscopy and X-ray diffraction. It is observed that the nascent sponge formed is highly unstable which transforms to a needle-like morphology almost immediately, which further transforms to rounded and finally to a bulk shape. Faceting of the surface and needle-shape formation were observed in these particles, this is probably due to anisotropy in the surface energy. The morphology of the sponge formed during the reduction influences the distillation process. The fine needle-like shape sponge morphology leads to particle ejection, which is explained to be due to curvature effect. This is responsible for the formation of unwanted mass during distillation. XRD line broadening analysis indicates that the individual sponge particles are free from structural defects (dislocation) and are nearly single crystalline in nature.

Interactions among Florida sponges. I. Reef habitats

Spatial interference competition is well described for many sessile marine invertebrates, but few studies have addressed interactions between neighboring sponges. We conducted transect surveys to assess interspecific interactions among sponges in coral reef habitats in Key Largo, Florida, USA. In total, 15 transect sites were surveyed at 5 reef locations with mean densities ranging from 13.0 ± 3.6 to 33.3 ± 5.9 sponges m -2 . The most abundant of over 43 sponge species observed were Amphimedon compressa, Aplysina cauliformis, Aplysina insularis, and Niphates erecta, while the least abundant were Hippospongia lachne, Ircinia campana, and Pseudaxinella lunaecharta. A nearest-neighbor technique was used to determine the degree and frequency of interactions between randomly selected sponge pairs. Overall, 40.4% of sponges occurred alone, 31.0% in proximity to, and 28.6% in contact with other sponge species. Among sponges in contact interactions, 18.7% were epibionts, 19.4% were basibionts, and a relationship could not be resolved for the remainder. Statistical analyses of the frequencies of each interaction category revealed that the ability to overgrow or resist overgrowth varied among species. For example, Aka coralliphagum, Ectyoplasia ferox, and Phorbas amaranthus occurred alone in >60% of their interactions and were never overgrown by other species with which they came into contact. In contrast, Agelas schmidti, Ircinia felix, Dysidea janiae, and Scopalina ruetzleri occurred alone in <30% of their interactions, with the first 2 species overgrown by, and the latter 2 overgrowing, most other species with which they came in contact. All contact interactions were further statistically examined, and 41 interspecific sponge pairs revealed significant overgrowth ability by 1 of the interacting species. While the over- growth ability of a species is dependent on sponge morphology, the ability to resist overgrowth is associated with the production of allelochemicals.

Greek and the phylum Porifera: a living language for living organisms

AbstractThis paper gives a detailed analysis of Greek language elements in sponge terminology and nomenclature, thus contributing to its comprehension by the scientists working on sponge biology and enlightening the extensive contribution of the Greek language to zoological terminology. The contemporary terminology of sponge morphology and the taxa names of the three living classes of the phylum Porifera, down to the genus level, were recorded and examined for their possible Greek origin. The analysis of the recorded material showed that 67% of the morphological terms and 78% of the taxa names were formed from Greek elements. Different patterns of term and name formation were revealed. Detailed etymological analysis is presented for all morphological terms and suprageneric taxa names built of Greek elements. The Greek words used for the formation of terms and names are listed and their English translation is given. More than 70% of the Greek words found were used only once to form terms or taxa names. The contribution of the Greek element in sponge nomenclature in all decades from 1759 up to the present was &gt;65%, with a slightly decreasing trend during the last two decades.

Polyetherimide membrane formation by the cononsolvent system and its biocompatibility of MG63 cell line

Polyetherimide (PEI) membrane could be prepared by immersion–precipitation process by using the N-methyl-2-pyrrolidone (NMP)–methylene chloride (MC) cononsolvent as the coagulation medium. The membrane, via scanning electron microscopy (SEM), showed a typically asymmetrical structure consisting of a thin and dense skin layer, sponge morphology in the cross-section and porous bottom surface. Trend expected on the basis of the phase diagram of the use of two solvents serving as a cononsolvent system for the membrane formation, replacing the traditional solvent–nonsolvent pair, was in reasonable agreement with the observed membrane morphology. Therefore, the principles of membrane formation established for the ternary systems with polymer–solvent–nonsolvent can be applied to a polymer–cononsolvent (solvent–solvent) system. Furthermore, the biocompatibility of the PEI membrane top (dense) and bottom (porous) surfaces was assessed in an in vitro model using the human osteoblast-like cell line MG63. Compared to cells grown on tissue culture polystyrene (TCPS), cells cultured on the PEI membranes had lower cell growth, but every single cell on the PEI membrane showed similar viability to control cells. SEM analysis showed comparable adhesion and confluence characteristics on all substrates. In addition, the levels of alkaline phosphotase (ALP), prostaglandin E2 (PGE 2) and transforming growth factor β1 (TGF-β1) cytokines produced by MG63 cells on the prepared PEI membranes, regardless of the top or bottom surface, were similar to those on TCPS. The results of this study suggest that the PEI membrane prepared from a cononsolvent system is a non-toxic, biocompatible substrate for the proliferation of human bone cells in vitro.

First observations on egg release in the oviparous sponge Chondrilla nucula (Demospongiae, Chondrosida, Chondrillidae) in the Mediterranean Sea

Abstract. The reproduction of the demosponge Chondrilla nucula in Portofino (Ligurian Sea, Italy) was studied during August 2001. Eighteen individuals were sampled and examined with light microscopy for the presence of gametes, and 5 individuals carrying oocytes were found. In addition to microscopic observations, reproductive individuals could be easily identified as female even at the macroscopic level because of the presence of a grayish layer in the mesohyl where oocytes were concentrated. Oogenesis resulted in modifications of the external sponge morphology and of the aquiferous system. Approximately one‐third of the sponge body was filled with oocytes with the consequent disappearance of choanocyte chambers in the reproductive portion of the sponge. Under laboratory conditions, we obtained fertilized eggs from females and observed the first stages of embryonic development. Our observations suggest that fertilization in specimens of Chondrilla nucula occurs internally and not in the water. During the 2 years following these observations, no reproductive specimens were found among the same population during the reported reproductive period.

Evidence for morphology-induced sediment settlement prevention on the tubular sponge Haliclona urceolus

Several mechanisms are known to assist the survival of sponges in highly sedimented environments. This study considers the potential of sponge morphology and the positioning of exhalant water jets (through the osculum) in the adaptation of Haliclona urceolus to highly sedimented habitats. This sponge is cylindrical with an apical osculum, which is common in sedimented subtidal habitats at Lough Hyne Marine Nature Reserve, Cork, Ireland. Fifteen sponges were collected, preserved (killed with the structure and morphology maintained) and then replaced in a high sediment environment next to a living specimen (at 24 m). After 5 days, the sediment settled on both living and preserved sponges was collected and dried. No sediment was collected from living sponges, while preserved specimens had considerable amounts of settled sediment on their surfaces. The amount of sediment collected on these preserved specimens was significantly linearly correlated with sponge dry weight, maximum diameter and oscula width (R2>0.70, P<0.001, df=14). Observations of flow direction (using coloured dye) through H. urceolus showed that water is drawn into the sponge on its underside and exits via a large vertically pointing osculum. Sponge morphologies (shape) have often been considered as a means of passive adaptation to a number of different environmental parameters with oscula position enabling entrained flow through the sponge in high flow conditions. However, this study shows how the combination of sponge morphology (tubular shape) and positioning of the osculum may enable H. urceolus to survive in highly sedimented environments. Similar mechanisms may also aid the survival of some deep-water sponge species with similar morphologies.

Influence of sponge morphology on the composition of the polychaete associated fauna from Rocas Atoll, northeast Brazil

The relationships between the morphology of sponges and variables describing their harbored polychaete fauna were analyzed along Rocas, the only known South Atlantic Atoll, together with the location on host and feeding habits. The identification and quantification of all the associated organisms highlighted the dominance of polychaetes. The adults of the symbiotic species Haplosyllis spongicola were the most dominant sponge endobionts. However, both juveniles and epitokes (reproductive individuals) of H. spongicola were also found, suggesting that this species completes its life cycle inside the host. Polychaete density was significantly greater in lobate sponges than in massive and encrusting forms. Conversely, the highly specific symbiotic mode of life of H. spongicola species seems to play a major role in structuring the composition of the polychaete fauna in relation to sponge morphotypes along Rocas Atoll.

The influence of crosslinking agents and diamines on the pore size, morphology and the biological stability of collagen sponges and their effect on cell penetration through the sponge matrix.

Artificial skin substitutes based on autologous keratinocytes cultured on collagen substrata are being developed for treating patients with severe burns. The properties of the collagen substrate can be manipulated, for example, by crosslinking, to optimize desirable properties such as cell growth and penetration into the substrate, biological stability and mechanical strength. Collagen sponges crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDAC) and the diamine, diaminohexane, were used to determine the effect of crosslinking on pore size and morphology, on the stability of the crosslinked sponges both in cell culture media and during incubation with collagenase, and on the penetration of keratinocytes and fibroblasts through the sponge matrix. Crosslinking of the sponges reduced the pore size, particularly at the surface, and altered sponge morphology. After crosslinking the collagen fibers were thinner, and appeared lacy and delicate. Crosslinking also influenced sponge stability. In keratinocyte serum-free medium the pore size of plain collagen sponges increased with increasing incubation time, and crosslinking appeared to prevent this, and may have stabilized sponge structure. Incubation in serum-containing Dulbecco's minimum essential medium caused a marked reduction in pore size in both plain collagen and crosslinked collagen sponges. Crosslinking did not appear to influence this cell-free contraction of collagen sponges. Treatment of sponges with EDAC markedly increased the resistance of sponges to collagenase digestion. The penetration of both keratinocytes and fibroblasts was retarded by crosslinking the sponges. Fibroblasts penetrated through the sponges to a greater extent than keratinocytes, and their proliferation rate was faster. The total number of cells populating the crosslinked sponges after 10 days culture was approximately 50% of that on untreated collagen sponges. The mechanism responsible for this effect was different with the two crosslinkers used. Diaminohexane appeared to inhibit cell growth, whereas EDAC may have caused a decrease in cell adhesion to the sponges, without an apparent inhibition of growth rate. In terms of morphology, fibroblasts were elongated to a greater extent on crosslinked sponges, and alligned themselves along the collagen fibers. Keratinocytes grew in colonies on untreated sponges, but on crosslinked sponges they grew in isolation, with minimal cell-cell interactions. It may be necessary to reach a compromise to obtain the best combination of properties for using collagen sponges as substrata for artificial skin substitutes.

A Sponge Morphology in an Elementary Coacervate

A zwitterionic gemini surfactant forms a coacervate which is “elementary” in the sense that it consists of a single solute as opposed to the multicomponents (e.g., cetylpyridinium chloride/hexanol/water/NaCl) common in the coacervate literature. The gemini dissolves in water but then quickly separates as oily droplets which, despite the high water content of 83 wt %, are immiscible with water. Cryogenic temperature high-resolution scanning electron microscopy (cryo-HRSEM) examination of the droplets shows a distinct “sponge” structure. Although previously proposed for coacervate phases, a sponge morphology has never before been clearly depicted. The absence of previous electron microscopy (EM) pictures of the coacervate network is attributed to artifacts associated with transmission electron microscopy (TEM) methods, to the fragility of the coacervate toward physical perturbations, and to possible compositional changes with complex mixtures during sample preparation. When the gemini coacervate was exposed to mild shear, the honeycomb structure disappeared and was replaced by a lamellar phase.

The Choanosome of Hexactinellid Sponges

Three-dimensional images of the choanosome of hexactinellid sponges can help in explaining how these sponges mix cellular and syncytial tissues in a fine cobweb-like network. Plastic replicas of the water canals show that Rhabdocalyptus dawsoni has large, highly branched incurrent canals, and equally large, although less branched, excurrent canals that are studded with 60 (im-long flagellated chambers. Freeze-fractured, fixed specimens show the syncytial tissue, known as the trabecular reticulum, envelops cells in a thin collagenous mesohyl at the flagellated chambers in both R. dawsoni and Aphrocallistes vastus. Groups of archaeocytes are especially abundant in the mesohyl of R. dawsoni during summer months. A branch of the trabecular reticulum, the secondary reticulum, surrounds the collars in the flagellated chambers, effectively forcing water to be drawn through the collar microvilli. Another branch, the inner membrane, occupies up to 10% of flagellated chambers of sponges during all months of the year, but is especially prevalent in specimens which have been kept in sea water aquaria for several weeks. This three-dimensional view of hexactinellid tissues reinforces the conclusion that hexactinellid sponges be separated from other sponges at the subphylum level. Additional key words: Hexactinellida, Porifera, syncytium, sponge Sponge morphology has been studied for well over a century. These animals are considered to be simple, radially symmetric or asymmetric, diploblastic metazoans that carry out all the basic functions of ingestion and egestion, growth and reproduction with a very small complement of cell types. The Hexactinellida, however, differ fundamentally from other sponges in having a syncytial tissue (the trabecular reticulum) rather than cells, as their major tissue component (Reiswig 1979; Mackie & Singla 1983; Leys 1995). The uniqueness of the construction of the Hexactinellida has been recognized since these animals were first examined in the late 1800s. Bidder (1929) first proposed separating the Porifera into two phyla based partly on the difference in tissue organization between cellular and syncytial sponges. Later, Reid (1963) argued that this difference should be recognized at the subphylum level, but the lack of ultrastructural proof of syncytial tissues prevented sponge workers from unanimously accepting the proposal (Bergquist 1978). Because hexactinellids are predominantly deep water sponges, specimens were usually obtained by dredging, and consequently were in poor condition. The discovery of shallow-water populations accessible by a Present address: Department of Zoology, University of Queensland, Brisbane, QLD 4072, Australia. SCUBA in the late 1970s allowed the first ultrastructural examination of tissues and confirmed that the major tissue component in the sponge constitutes a single giant syncytium (Reiswig 1979; Mackie & Singla 1983). Advances in our understanding of the physiology (Perez 1996; Wyeth et al. 1996; Leys & Mackie 1997), development (Boury-Esnault & Vacelet 1994; BouryEsnault et al. 1999), and molecular biology (Koziol et al. 1997; Kruse et al. 1998) of hexactinellids have confirmed the unusual status of this group within the phylum Porifera. However, recent invertebrate texts have yet to acknowledge a proposal for subdivision of sponges into two subphyla (Reiswig & Mackie 1983). Because hexactinellid tissue is unusually difficult to preserve well for either transmission or scanning electron microscopy (TEM, SEM), it is possible that discrepancies in interpretation of preserved tissue by specialists in this field have been the reason why no text carries a clear description of the tissue organization of these sponges. Despite several excellent articles describing fixed tissues from some eight species of hexactinellids (e.g. Mackie & Singla 1983; Reiswig & Mehl 1991; Boury-Esnault & Vacelet 1994), a clear, three-dimensional picture of their tissues is still lacking. In other sponge groups the flagellated chambers and This content downloaded from 157.55.39.153 on Mon, 19 Sep 2016 04:45:05 UTC All use subject to http://about.jstor.org/terms

Thesaurus of sponge morphology

Boury-Esnault, Nicole, and Klaus Rutzler, editors. Thesaurus of Sponge Morphology. Smithsonian Contributions to Zoology, number 596, 55 pages, 305 figures, 1997.—This is a vade mecum of terms for describing all aspects of sponge morphology, such as habit, surface structure, consistency, and anatomy. Definitions of microscopic features include aquiferous system, cytology, reproductive structures, skeletal architecture, and calcareous and siliceous spicules. Terms were selected and reviewed by an international group of 10 experts in sponge systematics, during several workshops. Each entry is accompanied by a precise diagnosis and an illustration. Terms listed as rejected are those judged unsuitable, redundant, or preoccupied. The thesaurus will aid descriptions in future systematic papers, computerized data banks, and identification keys. The literature cited presents a historical perspective on similar attempts to create a precise terminology of sponge morphology and helps to further clarify the selected terms. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Annals of the Smithsonian Institution. SERIES COVER DESIGN: The coral Montastrea cavernosa (Linnaeus). Library of Congress Cataloging-in-Publication Data Thesaurus of sponge morphology / Nicole Boury-Esnault and Klaus Rutzler. p. cm.—(Smithsonian contributions to zoology ; no. 596) Includes bibliographical references (p. ). I. Sponges—Morphology—Terminology. I. Boury-Esnault, Nicole. II. Rutzler, Klaus. III. Series. QLl.S54no. 596 [QL374] 57l.3'I4'014-dc21 97-20213 © The paper used in this publication meets the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48—1984.

Chaetetid growth form and its controlling factors

Chactetid sponge morphology is examined to provide details on growth styles and their controlling factors. Chactetid growth forms range from laminar to domical. bulbous. columnar and complex branching in a variety of sizes. The chactetid skeleton began as a laminar unit comprising growth of many calicles across the substrate at the same time. Several styles of early growth. involving differential calicle growth rates and varying directions of adjacent calicle growth. are recognized. and result in complex arrangements of caliclcs in the skeleton. Despite this. the cross-sectional protile of the gross morphology at any stage of growth is usually a simple outline. implying that internal complexities of calicle development are modulated to produce an optimum cross-sectional outline for the individual chactetid. The morphological range of chactetids is similar to stromatoporoids. some tabulate. heliolitid and colonial rugose corals. some bryozoans. stromatolites. encrusting foraminifera and calcareous algae: the common environmental controlling factors of sedimentation and turbulence profoundly influenced growth form in all these organisms by virtue of their common sessile shallow marine habit. Chactetid growth forms show a general relationship to the environment: columnar and branching forms grew in quiet water. while laminar and domical were better adapted to environments of higher energies. The environmental adaptations of laminar forms. however. remain problematic. because they are found in both high and low energy facies. and interpretation depends strongly on facies study. Also. interpretation of all growth forms is suspected to relate to taxonomic aspects. as has been recognized for other groups. Unfortunately. chaetetid taxonomy is in need of revision. and at present no certain relationship has been demonstrated between taxonomy and growth form. Some modern calcareous sponges with a chaetetiform architccture also show similarities in growth form to fossil types. and may be subject to similar controls. □Chaetetid. calcified sponge. growth form. Pennsyloanian. North America.

Locomotion of sponges and its physical mechanism.

Active locomotion by individual marine and freshwater sponges across glass, plastic and rubber substrata has been studied in relation to the behavior of the sponges' component cells. Sequential tracing of sponge outlines on aquarium walls shows that sponges can crawl up to 160 microns/hr (4 mm/day). Time-lapse cinemicrography and scanning electron microscopy reveal that moving sponges possess distinctive leading edges composed of motile cells. Sponge locomotion was found to be mechanically similar to the spreading of cell sheets in tissue culture both with respect to exertion of traction (which causes the wrinkling of rubber substrata) and with respect to the patterns of adhesive contacts formed with the substratum (as observed by interference reflection microscopy). Other similarities include the orientation of sponge locomotion along grooves and the preferential extension onto more adhesive substrata. Neither the patterns of wrinkling produced in rubber substrata nor the distributions of adhesive contacts seen by interference reflection microscopy show evidence of periodic, propagating waves of surface contractions, such as would be expected if the sponges' mechanism of locomotion were by peristalsis or locomotory waves. Our observations suggest that the displacement of sponges is achieved by the cumulative crawling locomotion of the cells that compose the sponge's lower surface. This mode of organismal locomotion suggests new explanations for the plasticity of sponge morphology, seems not to have been reported from other metazoans, and has significant ecological implications.