bluuebunny/crossref_metadata_2025 huggingface dataset:
The proventriculus of the carpenter bee, Xylocopa virginica virginica (L.), with special reference to bacteria‐containing luminal tunnels
Authors: Chapman George B. , Abu‐Eid Cherine
Published: August 2010

Abstract. Four tunnels off the lumen of the proventriculus of the carpenter bee, Xylocopa virginica virginica, have been discovered. Light and electron micrographs revealed the presence in the tunnels of gram‐positive, rod‐shaped bacteria, some of which showed division stages. The occurrence of the bacteria exclusively in the tunnels—not in the lumen of the proventriculus—makes speculation as to their function difficult. The function of the tunnels is also obscure, as no glands were seen emptying into them. The bacteria may be symbionts that release enzymes into the tunnels, which are subsequently transported to the midgut to aid digestion. They could also be parasites. This is the first report of such bacterial‐containing tunnels in insects.
Parasitism of Leptasterias spp. (Echinodermata: Asteroidea) by the ciliated protozoan Orchitophrya stellarum (Scuticociliata)
Authors: Stickle William B. , Weidner Earl H. , Kozloff Eugene N.
Published: August 2010

Abstract. The parasitic ciliate Orchitophrya stellarum was found in the testes of brooding, winter‐spawning Leptasterias spp. from San Juan Island, Washington, but not in the testes of Leptasterias spp. from the Lynn Canal, Alaska. Dense populations of the ciliate were localized within the fuller areas of testes, where sperm counts were significantly reduced. The ciliates were loaded with phagosomes, some of which contained sperms in various stages of digestion. Leptasterias spp. are not as severely impacted by this ciliated protozoan parasite as Pisaster ochraceus. Leptasterias spp. may serve as seasonal hosts for O. stellarum; this ciliate lives in seawater and in ripe males of winter‐brooding and spring‐summer broadcasting sea stars. The wet weight of parasitized and non‐parasitized males did not differ. The sex ratio did not deviate from the expected (1:1) in any population except at Point Louisa, Alaska, where males outnumbered females. Testis indexes of parasitized males from 2 of the 4 locations on San Juan Island, Washington were significantly reduced relative to non‐parasitized males, indicating a loss of sperm output during spawning.
Noradrenaline reduces the stimulatory effect of interleukin‐1α on reactive oxygen species production by oyster immunocytes
Authors: Lacoste Arnaud , Malham Shelagh K. , Cueff Anne , Poulet Serge A.
Published: August 2010

Abstract. A growing body of evidence suggests that interleukin‐1α (IL‐1α) is present in invertebrates. Both invertebrate and human IL‐1α can bind to invertebrate receptors and stimulate invertebrate immune functions. The present study shows that IL‐1α increases reactive oxygen species (ROS) production by oyster immunocytes. However, physiological doses of noradrenaline (NA) exert a suppressive effect on IL‐1α stimulation in vitro. The β‐adrenoceptor agonist isoproterenol mimicked the effects of NA and the β‐adrenoceptor antagonist propanolol blocked the NA‐induced suppression of hemocyte responsiveness to IL‐1α. The type IV phosphodiesterase inhibitor rolipram acted in synergy with isoproterenol to reduce hemocyte response to IL‐1α and the protein kinase A inhibitor H‐89 suppressed the effects of isoproterenol. These results suggest that circulating NA impairs IL‐1α‐stimulation of oyster hemocyte via a β‐adrenoceptor/cyclic AMP/protein kinase‐A signaling pathway. Considering that mollusc immunocytes secrete NA, an autocrine regulatory loop may also modulate the ability of these cells to respond to IL‐1α.
Effects of exogenous interleukin‐1β on primary sporocysts of Schistosoma mansoni (Trematoda) incubated with plasma and hemocytes from schistosome‐susceptible and resistant Biomphalaria glabrata (Gastropoda)
Authors: Granath Willard O. , Connors V.A. , Raines Anne E.
Published: August 2010

Abstract. The cytokine interleukin‐1β (IL‐1β) mediates interactions of immune and inflammatory cells in mammals. Previous reports also have linked plasma (cell‐free hemolymph) levels of IL‐1β in the snail Biomphalaria glabrata to resistance against Schistosoma mansoni. In the present study, fluorescent probes were used to study larval schistosome and snail hemocyte viability during in vitro encounters. Hemolymph (plasma and hemocytes) from schistosome‐susceptible (M‐line) and resistant (13–16‐R1) B. glabrata was added to sporocysts of S. mansoni and the viability of hemocytes and parasites was assessed. Next, IL‐1β was added to sporocyst‐hemolymph samples, the viability of sporocysts and hemocytes determined and then compared to control assays. The number of live sporocysts present after incubation for 1 h with hemolymph from M‐line snails was significantly greater than the number seen when hemolymph from 13–16‐R1 snails was tested. Nearly all sporocysts survived the 1 h incubation with M‐line hemolymph, and most of the hemocytes attached to sporocysts were dead. In contrast, nearly all sporocysts were dead when hemolymph from 13–16‐R1 snails was tested, and most attached hemocytes were alive. Addition of IL‐1β to M‐line hemolymph resulted in a dramatic increase in sporocyst death. Addition of IL‐1β to 13–16‐R1 hemolymph produced a small but significant increase in the rate of sporocyst death. These results indicate that the concentration of IL‐1β present in hemolymph from B. glabrata is directly related to the ability of this snail to kill S. mansoni sporocysts in vitro.
Tunic cells in pyrosomes (Thaliacea, Urochordata): cell morphology, distribution, and motility
Authors: Hirose Euichi , Ohshima Chie , Nishikawa Jun
Published: August 2010

Abstract. Cellular components of the tunic were histologically examined in 3 pyrosome species representing all 3 genera of the order: Pyrosoma atlanticum, Pyrosomella verticillata, and Pyrostremma spinosum. Three cell types are distributed in the tunic. Tunic amebocytes, irregularly shaped and motile, often contain granules and/or phagosomes. Spherical tunic cells contain many round vesicles with eosinophilic and acidic materials. Tunic net cells form a cellular network in which their long filopodia connect with one another. The net cells are densely distributed just beneath the tunic surface lining the common cloacal cavity and may produce tension to maintain the colony shape. The presence of net cells suggests a phylogenetic relationship between pyrosomes and some aplousobranch ascidians. Test fibers are multicellular cords that run in the tunic and connect the zooids. In P. atlanticum, they are attached to they are attached to the epidermal cells of the zooids, and transverse cloacal muscles are attached to the other (proximal) side of the epidermal cells. The test fibers may mediate coordination of the zooids and control muscle contraction.
Attachment to the substrate by soft coral fragments: desmocyte development, structure, and function
Authors: Barneah Orit , Malik Zvi , Benayahu Yehuda
Published: August 2010

Abstract. Pieces cut from colonies of the soft coral Dendronephthya hemprichi exhibited rapid and effective attachment to hard surfaces. Attachment involved development of root‐like processes (RLPs), which appeared at the basal part of the fragment 4 days after its removal from the colony. The fine structural changes and cascade of cellular events occurring in the RLP before and after attachment were studied using SEM, TEM, and LM. The epidermis of the RLPs is actively involved in the attachment process and several distinct phases are documented: appearance of numerous oval vesicles, extrusion of these vesicles resulting in the formation of an outer layer composed of extracellular organic matrix and organellar debris, which functions as an adhesive device leading to initial attachment. The latter phase was followed by the formation of desmocytes, which develop in the RLP epidermis and function as anchoring devices, mediating the firm attachment of the fragment to the substrate. This is the first evidence among anthozoans that desmocytes play an active role in anchoring tissue to substrate and thus extends the range of functions exhibited by desmocytes among anthozoans.
Chemosensory and feeding responses of the nudibranch Aeolidia papillosa to the symbiotic sea anemone Anthopleura elegantissima
Authors: Seavy Barbara Emerson , Muller‐Parker Gisèle
Published: August 2010

Abstract. The aeolid nudibranchAeolidia papillosa is an important predator on the sea anemone Anthopleura elegantissima, a host to two kinds of endosymbiotic algae: zooxanthellae and zoochlorellae. The possible influence of the algae on the nudibranch's predatory response to this anemone was examined in a laboratory study. In chemosensory experiments, the nudibranch detected and chose anemone scent over a seawater control, but in both chemosensory and feeding experiments showed no preference for zooxanthellate or zoochlorellate anemones. Ingestive conditioning on zooxanthellate or zoochlorellate anemones had no effect on choice of these two anemone types in chemosensory experiments. Comparisons of the productivity and photosynthetic pigments of algae obtained from nudibranch feces and from anemones show that both algae survive passage through the nudibranch gut. The productivity of fecal zooxanthellae was 1.6X greater than that of zooxanthellae freshly isolated from anemones, although the chlorophyll a content of fecal zooxanthellae was reduced. The productivity and amount of pigments were the same for zoochlorellae in nudibranch feces and freshly isolated from anemones. Comparing fecal and isolated algae, there was no significant difference in the percentage of zooxanthellae in the process of cell division. However, the percentage of dividing cells was 2.6X higher in fecal than in freshly isolated zoochlorellae (18% and 6.9% respectively). Although the endosymbiotic algae do not make their host more or less attractive to the nudibranch, this predator may play an important role in maintaining the symbiotic relationship of Anthopleura elegantissima with zooxanthellae and zoochlorellae by providing viable algae in its feces as a source for the anemone host.
Ultrastructure of the mushroom body: digestion during metamorphosis of Utterbackia imbecillis (Bivalvia: Unionidae)
Authors: Fisher Ginger R. , Dimock Ronald V.
Published: August 2010

Abstract. Larvae of the freshwater mussel Utterbackia imbecillis metamorphose to juveniles either during their attachment to a host fish, or in vitro in a culture medium. This transformation includes degeneration of larval structures and development of the juvenile morphology. Early in metamorphosis the cells comprising the larval mantle enlarge and project into the mantle cavity, forming a structure referred to as the mushroom body. Its cells, which are ultrastructurally very similar to digestive cells of adult bivalves, are involved in pinocytosis or phagocytosis of the larval adductor muscle and of tissue from the host fish that is enclosed between the larval shells. Ingested material is passed from pinosomes to heterophagosomes which in turn fuse with heterolysosomes, where final degradation of ingested material occurs. Acid phosphatase activity was detected in heterophagosomes and heterolysosomes of all animals examined. In larvae that metamorphosed in vitro, the apical cytoplasm of the cells of the mushroom body, and the extracellular spaces among them, also exhibited acid phosphatase activity. Larvae reared on a host fish accumulated substantial deposits of lipids and glycogen within larval mantle cells during metamorphosis, whereas larvae reared in vitro did not. The larval mantle cells which constitute the mushroom body appear to be the primary sites of intracellular digestion of the larval adductor muscle and host tissue during metamorphosis.
Ecdysis in scorpions: supine behavior and exuvial ultrastructure
Authors: Gaban R. David , Farley Roger D.
Published: August 2010

Abstract. Ecdysis in scorpions has some common features in all species in which it has been examined. Immature scorpions about to molt become less active, and the cuticle changes in appearance. When humidity and other conditions are suitable, the animal begins ecdysis with cheliceral and pedipalpal movements and internal processes that tear the pleural membrane just ventral to the anterior and lateral edges of the carapace. The carapace is pushed upward from within, and the animal starts to emerge through the opening made by the elevated carapace. This is usually done in the prone position. As the anterior body emerges, the pedipalps and walking legs are stretched posteriorly with their distal ends temporarily confined within the old exoskeleton. The buthid scorpions Androctonus australis and Parabuthus transvaalicus become supine before they begin to emerge. Ecdysis is completed lying supine, and the animal rights itself shortly thereafter. A turnover from upright to supine is not seen at any other time in scorpions. After prone or supine extraction, the exuvium includes the cuticle of booklungs, bristles, and sensilla and is relatively intact except for the wedge‐shaped opening at the anterior end.
The digestive system of the hydrothermal vent polychaete Galapagomystides aristata (Phyllodocidae): evidence for hematophagy?
Authors: Jenkins Cheryl D. , Ward Megan E. , Turnipseed Mary , Osterberg Joshua , Van Dover Cindy Lee
Published: August 2010

Abstract. Anatomical, histological, and ultrastructural investigation of the hydrothermal vent phyllodocid Galapagomystides aristata shows that this unusual polychaete has a normal mouth and foregut but a highly modified midgut with a blood‐filled lumen. The foregut includes a protrusible proboscis armed distally with minute spines. Midgut tissues contain concentrically banded spherocrystals, composed mainly of iron, phosphorus, and silicon, and abundant lipid droplets. The blood‐filled midgut lumen extends to the final segment of the worm, but we find no sign of an anus. There is no evidence of symbiotic bacteria in tissues of G. aristata. Stable isotope analyses indicate that G. aristata is likely to be a secondary consumer. We propose that these worms are hematophagous, although they lack many common anatomical adaptations for a blood‐sucking way of life.
Putative sensory structures in marine bryozoans
Authors: Shunatova Natalia N. , Nielsen Claus
Published: August 2010

Abstract. SEM studies of 21 species of marine bryozoans demonstrated that the abfrontal side of the tentacles bears a row of mono‐ or multiciliated cells, which are presumably sensory. In stenolaemates, the abfrontal cells, as well as the cells at the tentacle tips and the laterofrontal cells, are monociliated. In the 17 gymnolaemate species studied, each tentacle tip bears at least 3 multiciliated cells, each with a tuft of 5–7 stiff cilia of various lengths. On the abfrontal tentacle surface, mono‐ and multiciliated cells alternate, but all species studied have multiciliated cells at the base and the tip of each tentacle. In live animals, single cilia perform occasional flicks, whereas the tufts of 7–15 cilia on the multiciliated cells are immotile. Length and number of abfrontal cilia vary between species. Two types of multiciliated, putative sensory organs were found on the introvert of some gymnolaemates. One has an apical knob surrounded by a ring of cilia; the other has an apical tuft of cilia. The ultrastructure of the sensory cells of tentacles and introvert was studied in Rhamphostomella ovata. Our observations on both fixed and living material all suggest that these cells are primitive mechanoreceptors. The few species lacking ciliary structures on the introvert have long proximal ciliary tufts on the abfrontal tentacle surface.
Impact of males on variation in the reproductive cycle in an androdioecious desert shrimp
Authors: Zucker Naida , Aguilar Gabriela A. , Weeks Stephen C. , McCandless L. Garner
Published: August 2010

Abstract. In the clam shrimp Eulimnadia texana and some other species of desert ephemeral pool‐dwelling branchiopod crustaceans, males coexist with hermaphrodites. The hermaphrodites can mate with males or can fertilize their own eggs but cannot mate with other hermaphrodites. Understanding the evolutionary dynamics of this mixed mating system, known as androdioecy, requires a basic knowledge of the reproductive behavior of this species. Here we describe the reproductive cycle of hermaphrodites when isolated and when in the presence of a male. Videos were analyzed to provide a description of egg movement from the ovotestes to the brood chamber. Through time‐lapse photography, we determined that paired hermaphrodites carried their brood longer and swam fast for a greater duration than did isolated hermaphrodites. Isolated hermaphrodites dug more preliminary burrows before burying their clutch and had longer inter‐clutch intervals than did paired hermaphrodites. These observations suggest that hermaphrodites may behave in ways that maximize the likelihood of mating, and that males may interfere with hermaphrodites during egg laying.
On bivalve phylogeny: a high‐level analysis of the Bivalvia (Mollusca) based on combined morphology and DNA sequence data
Authors: Giribet Gonzalo , Wheeler Ward
Published: August 2010

Abstract.Bivalve classification has suffered in the past from the crossed‐purpose discussions among paleontologists and neontologists, and many have based their proposals on single character systems. More recently, molecular biologists have investigated bivalve relationships by using only gene sequence data, ignoring paleontological and neontological data. In the present study we have compiled morphological and anatomical data with mostly new molecular evidence to provide a more stable and robust phylogenetic estimate for bivalve molluscs. The data here compiled consist of a morphological data set of 183 characters, and a molecular data set from 3 loci: 2 nuclear ribosomal genes (18S rRNA and 28S rRNA), and 1 mitochondrial coding gene (cytochromecoxidase subunit I), totaling ∼3 Kb of sequence data for 76 molluscs (62 bivalves and 14 outgroup taxa). The data have been analyzed separately and in combination by using the direct optimization method of Wheeler (1996), and they have been evaluated under 12 analytical schemes. The combined analysis supports the monophyly of bivalves, paraphyly of protobranchiate bivalves, and monophyly of Autolamellibranchiata, Pteriomorphia, Heteroconchia, Palaeoheterodonta, and Heterodonta s.l., which includes the monophyletic taxon Anomalodesmata. These analyses strongly support the conclusion that Anomalodesmata should not receive a class status, and that the heterodont orders Myoida and Veneroida are not monophyletic. Among the most stable results of the analysis are the monophyly of Palaeoheterodonta, grouping the extant trigoniids with the freshwater unionids, and the sister‐group relationship of the heterodont families Astartidae and Carditidae, which together constitute the sister taxon to the remaining heterodont bivalves. Internal relationships of the main bivalve groups are discussed on the basis of node support and clade stability.
Behavior of the yolk nuclei during embryogenesis, and development of the midgut diverticulum in the horseshoe crab Limulus polyphemus
Authors: Kimble Mary , Coursey Yvonne , Ahmad Nina , Hinsch Gertrude W.
Published: August 2010

Abstract. Classical studies of horseshoe crab development have provided relatively little information about the earliest stages, and the contribution of yolk cells and yolk nuclei—a deficiency due in large part to the difficulty of preparing the eggs and embryos for sectioning. Using newly developed histological resins, we show that the yolk nuclei undergo a series of changes during embryogenesis, before cellularizing and forming the midgut epithelium during the first larval stage. The digestive diverticulum forms in a 2‐step process. A mesodermally derived lamina divides the yolk mass into distinct lobes, defining the boundaries of the digestive caeca. The yolk nuclei then cellularize to form the midgut epithelium.
Spanning the gap: experimental determination of paratenic host specificity of horsehair worms (Nematomorpha: Gordiida)
Authors: Hanelt Ben , Jr. Janovy John
Published: August 2010

Abstract. Details of the life cycle of freshwater nematomorphs (gordiids) remain unclear. Free‐living aquatic larval gordiids must make a critical transition from an epibenthic aquatic environment to terrestrial hosts. In order to identify potential hosts capable of bridging this ecological gap, the specificity of paratenic hosts of three common species of North American gordiids was investigated. All three species were characterized by an identical infection pattern: low host specificity. Gordiids were able to encyst within annelids, mollusks, crustaceans, insects and a vertebrate. Three species of putative host (a turbellarian, a water mite, and a mosquito larva) were not infected with any of the gordiid species. Internal defense reactions (IDR) and feeding behaviors are implicated as preventing infection in these species. Several of the other host species produced either an IDR or an immune reaction to the cysts, although reactions to the cysts were highly variable between species. In most species, IDR did not cause noticeable harm to the encysted larvae. It is proposed that although many species are easily infected with gordiid cysts, most do not act as natural paratenic hosts. For some of these host groups, especially snails, a role as reservoir host is suggested. Of all hosts included in this study, aquatic insects were identified as the hosts likely responsible for spanning the ecological gap and acting as true hosts for gordiids.
Pharynx, esophagus, and associated structures in the booklouse, Liposcelis divinatorius
Authors: Chapman George B.
Published: August 2010

Abstract. Ultrastructural features of the pharynx, esophagus, and associated intrinsic visceral muscular and nervous structures of the booklouse, Liposcelis divinatorius, were studied to determine whether the anatomical arrangements of these structures differed from the general pattern found in insects. The results are compared with previous light microscope studies of this tiny insect. Variations from the usual arrangement reported for intrinsic visceral muscles associated with the pharynx in insects are described. Intrinsic visceral muscles include a narrow band of circularly disposed fibers and both extra‐circular and intra‐circular longitudinally disposed fibers. This represents a departure from the slightly developed inner longitudinal and more prominent outer circular fibers seen in most insects. The outer surface of some circular muscle cells has apparently unique pouches packed with mitochondria, which contain many cristae. Numerous bacteroids appear in the esophageal epithelial cells and in the sub‐esophageal ganglion. Nerve processes associated with the foregut contain neurotubules, synaptic vesicles, and electron‐dense granules.
Immunohistochemistry of chaetognath body wall muscles
Authors: Royuela Mar , Astier Catherine , Grandier‐Vazeille Xavier , Benyamin Yves , Fraile Benito , Paniagua Ricardo , Duvert Michel
Published: August 2010

Abstract. A light and electron immunohistochemical study was carried out on the body wall muscles of the chaetognath Sagitta friderici for the presence of a variety of contractile proteins (myosin, paramyosin, actin), regulatory proteins (tropomyosin, troponin), and structural proteins (α‐actinin, desmin, vimentin). The primary muscle (∼80% of body wall volume) showed the characteristic structure of transversely striated muscles, and was comparable to that of insect asynchronous flight muscles. In addition, the body wall had a secondary muscle with a peculiar structure, displaying two sarcomere types (S1 and S2), which alternated along the myofibrils. S1 sarcomeres were similar to those in the slow striated fibers of many invertebrates. In contrast, S2 sarcomeres did not show a regular sarcomeric pattern, but instead exhibited parallel arrays of 2 filament types. The thickest filaments (∼10–15 nm) were arranged to form lamellar structures, surrounded by the thinnest filaments (∼6 nm). Immunoreactions to desmin and vimentin were negative in both muscle types. The primary muscle exhibited the classical distribution of muscle proteins: actin, tropomyosin, and troponin were detected along the thin filaments, whereas myosin and paramyosin were localized along the thick filaments; immunolabeling of α‐actinin was found at Z‐bands. Immunoreactions in the S1 sarcomeres of the secondary muscle were very similar to those found in the primary muscle. Interestingly, the S2 sarcomeres of this muscle were labeled with actin and tropomyosin antibodies, and presented no immunore‐actions to both myosin and paramyosin. α‐Actinin in the secondary muscle was only detected at the Z‐lines that separate S1 from S2. These findings suggest that S2 are not true sarcomeres. Although they contain actin and tropomyosin in their thinnest filaments, their thickest filaments do not show myosin or paramyosin, as the striated muscle thick myofilaments do. These peculiar S2 thick filaments might be an uncommon type of intermediate filament, which were labeled neither with desmin or vimentin antibodies.
Svenzea zeai, a Caribbean reef sponge with a giant larva, andScopalina ruetzleri: a comparative fine‐structural approach to classification (Demospongiae, Halichondrida, Dictyonellidae)
Authors: Rützler Klaus , van Soest Rob W. M. , Alvarez Belinda
Published: August 2010

Abstract.Svenzea zeai, abundant on many deep Caribbean fore‐reef habitats but of uncertain systematic position within the Demospongiae, is closely examined histologically and cytologically for evidence of its phylogenetic relationship beyond the traditional analysis of gross morphology and skeletal structure. We document thatS. zeaiis a bacteriosponge containing substantial quantities of unicellular photosynthetic and autotrophic microbes; that the most abundant cell type is an unusual cell with refractile granules that only few species share and whose composition and function are still enigmatic; and that it produces the largest—by a factor of 3—embryos and larvae recorded in the phylum Porifera. A combination of characters such as the granular cells, ciliary pattern, and aspects of larval shape and behavior are comparable with those ofScopalina ruetzleri, family Dictyonellidae, a prominent member of the Caribbean mangrove community. These results support our earlier decision to establishSvenzeaas a new genus in Dictyonellidae to accommodate its unprecedented skeletal structure, styles in isodictyal reticulation.
Musculature of Notholca acuminata (Rotifera: Ploima: Brachionidae) revealed by confocal scanning laser microscopy
Authors: Sørensen Martin V. , Funch Peter , Hooge Matthew , Tyler Seth
Published: August 2010

Abstract. The body‐wall and visceral musculature of Notholca acuminata was visualized using phalloidin‐linked fluorescent dye under confocal laser scanning microscopy. The body‐wall musculature includes dorsal, lateral, and ventral pairs of longitudinally oriented body retractor muscles, two pairs of head retractors, three pairs of incomplete circular muscles, which are modified into dorso‐ventral muscles, and a single pair of dorsolateral muscles. The visceral musculature consists of a complex of thick muscles associated with the mastax, as well as several sets of delicate fibers associated with the corona, stomach, gut, and cloaca, including thin longitudinal gut fibers and viscero‐cloacal fibers, never before reported in other species of rotifers. The dorsal, lateral, and ventral retractor muscles and the incomplete circular muscles associated with the body wall appear to be apomorphies for the Rotifera. Muscle‐revealing staining shows promise for providing additional information on previously unrecognized complexity in rotifer musculature that will be useful in functional morphology and phylogenetic analyses.
Morphology of Floscularia ringens (Rotifera, Monogononta) from egg to adult
Authors: Fontaneto Diego , Melone Giulio , Wallace Robert L.
Published: August 2010

Abstract. Floscularia ringens is a cosmopolitan, sessile rotifer (class Monogononta) that lives inside a tube it constructs from numerous small, rounded pellets. Adults of F. ringens produce parthenogenetic eggs that are retained within the tube. Upon hatching, juveniles remain within the maternal tube for a short time completing their development before swimming away. The free‐swimming juvenile has a conical body, short foot, small corona, and mastax with trophi, but appears unable to feed. After a short time (<1 day), the young rotifer attaches permanently to a substrate and its morphology changes radically: the corona develops 4 wide lobes and the foot elongates, becoming slender and retractable. Once the corona has developed, the young animal begins to feed by producing filtering currents, and also starts to build its own tube. Here we report 4 new morphological details regarding this species. (1) A specialized epidermal groove is present on the trunk in front of the cloaca. (2) A small hole is located in the center of the inner surface of each pellet of the tube. (3) The muscles inside the foot are U‐shaped in transverse section. (4) The size of the trophi remains unchanged during growth of the juvenile into an adult.
Biology and conservation of the rare New Zealand land snail Paryphanta busbyi watti (Mollusca, Pulmonata)
Authors: Stringer Ian A.N. , Bassett Suzanne M. , McLean Megan J. , McCartney Jay , Parrish G. Richard
Published: August 2010

Abstract. The biology of Paryphanta busbyi watti, an endangered carnivorous land snail, was studied mostly by following large juvenile and adult snails with harmonic radar. The snails are nocturnally active and most (79%) hide during the day under leaf litter or in dense vegetation. Fecal analysis showed that the diet is primarily earthworms, but some cannibalism of smaller snails occurs. Empty shells appear to be an additional source of dietary calcium. Mating occurred most frequently between April and July. Mating snails stayed together for 4–7 days, and each pair reversed their positions at least twice. Four snails were first found mating 151–1240 d after they acquired adult shells, and 7 snails were observed mating a second time after 66–298 d. We found 8 nests and observed 6 snails ovipositing; 5 snails laid eggs in holes they dug and one laid eggs in a crevice between rocks. In 2 instances, oviposition was recorded 52 and 140 d after mating. Snails were estimated to lay on average ∼17.5 eggs per year in 3–5 clutches. Most oviposition was observed in August/September, but some occurred between November and February. Of the snails that died, pigs killed 13.6% and humans inadvertently killed another 13.6%. Other snails died from unknown causes mostly during the drier and warmer months, from November to April. This large land snail survives in the presence of introduced predators, but some life history traits could predispose it to a rapid decline in numbers if new predators arrive.
Unique morphology in the living bathyal feather star, Atelecrinus (Echinodermata: Crinoidea)
Authors: Messing Charles G.
Published: August 2010

Abstract. Examination of the living bathyal feather star, Atelecrinus, using light and scanning electron microscopy reveals a series of morphological features, some apparently unique within the Crinoidea, which forces a reassessment of the relationship of the genus to other living feather stars. In the cavernous centrodorsal cavity, interradial buttresses end with a shallow oral concavity or deep pit. Two adjacent axils each bear a large distolateral calcareous process of unknown function that resembles a shoe with a deeply ridged sole. These processes project into the visceral mass with their “soles” apposed—the only known case among living crinoids in which a skeletal feature appears asymmetrically on two of five rays. Articular facets of distal brachials bear one distally‐projecting, distal muscular fossa that overlaps a recumbent muscular fossa on the succeeding ossicle. Apposed projecting and recumbent fossae alternate sides on successive ossicles. The arm terminates in a long filament that lacks pinnules. Finally, modified ambulacral lappets resembling sessile pedicellariae but unsupported by skeletal plates flank the ambulacral grooves along the middle and proximal arms. Two of the four genera in the Atelecrinidae, extant monotypic Sibogacrinus anomalus and Cretaceous Jaekelometra, are removed from the family and treated as incertae sedis. Unique cirrus sockets are found in Atelecrinus and Atopocrinus sibogae (the only other remaining atelecrinid); members of Atopocrinus share unique ray morphology with those of the Pentametrocrinidae, and uniquely modified distal brachials are shared by individuals of Atelecrinus and Pentametrocrinus varians. However, the relationship of Atelecrinus to other feather stars remains unclear. The genus may represent a highly derived, paedomorphic comatulid as suggested by its unmetamorphosed basal ring and lack of proximal pinnules, or a non‐comatulid distinguished by its cirrus sockets, skeletal processes and pedicellaria‐like features. Robust answers require fresh material suitable for ultra‐structural and molecular analyses.
Internal brooding of clonal propagules by a sea anemone, Anthopleura sp.
Authors: Isomura Naoko , Hamada Keiko , Nishihira Moritaka
Published: August 2010

Abstract. We investigated the seasonal prevalence of reproductive activities and of the development of brooded propagules in an intertidal sea anemone, Anthopleura sp., on the rocky shore of Mutsu Bay, in northern Japan. A monthly examination of anemones, by dissection and histological techniques, revealed no sign of gonad development, but did reveal that they produce and internally brood propagules throughout the year. Release of propagules was observed in the field. This anemone population appears to be entirely asexual and agametic, and may persist solely through clonal propagation.
Colony growth responses of the Caribbean octocoral, Pseudopterogorgia elisabethae, to harvesting
Authors: Castanaro John , Lasker Howard R.
Published: August 2010

Abstract. Colonies of the branching Caribbean gorgonian Pseudopterogorgia elisabethae were subjected to partial mortality at 2 sites in the Bahamas to study how colony growth responds to disturbances such as harvesting, grazing, and storm damage. Colonies were clipped so that either 4 branches or 10 branches remained. Growth rates of branches were then monitored over 1 year and compared with nearby unclipped colonies. No significant differences were found between branch extension rates among the 3 treatments. Extension rates of newly formed branches were significantly greater in all treatments than among branches present at the start of the experiment. Per capita branching rates were greater on the more severely clipped colonies and were smallest on control colonies. The absolute number of branches that became mother branches did not differ among treatments. Colonies clipped so that 4 and 10 branches remained had the same average number of mother branches per colony, and there was no significant difference between treatments in the average number of new branches formed on the colonies. Per capita branching rates were significantly different among treatments only because the relative proportion of branches that became mother branches was higher in colonies with four branches than in treatments with more initial branches. Total growth (cumulative growth on all branches) was not significantly different between the 2 clipped treatments. Many of the control colonies suffered extensive damage, which may have obscured the comparison of clipped and unclipped treatments; however, within the range of these clipping treatments, differing levels of partial mortality did not lead to different recovery rates. The lack of treatment effects is particularly relevant to assessing the effects of harvest techniques on the recovery and productivity of harvested, naturally occurring, colonies.
A light‐ and electron‐microscopic study of enzymes in the embryonic shell‐forming tissue of the freshwater snail, Biomphalaria glabrata
Authors: Marxen Julia C. , Witten P. Eckhard , Finke Doreen , Reelsen Oliver , Rezgaoui Meriem , Becker Wilhelm
Published: August 2010

Abstract. The mode of formation of the molluscan exoskeleton is still poorly understood, but studies on adult snails indicate that enzymes involved in vertebrate bone formation also participate in mollusc shell formation. The enzymes peroxidase, alkaline phosphatase, and acid phosphatase are expressed in a constant pattern and help to identify the different zones of the adult shell‐forming tissue. The present study evaluates whether the expression of these enzymes is also a tool for the identification of the developing zones of the embryonic shell‐forming tissue. Thus, we analyzed the temporal and spatial activity of the above‐mentioned enzymes and of tartrate‐resistant acid phosphatase in the shell forming tissues in Biomphalaria glabrata. Embryos of different age groups and adults were studied; alkaline phosphatase activity was seen in very young embryos in the shell field invagination prior to the secretion of any shell material, while peroxidase activity was present from the start of the periostracum production. Acid phosphatase, found in considerable amounts in yolk granules and albumen cells, appeared in the embryonic shell‐forming tissue in relatively few Golgi stacks. Tartrate‐resistant phosphatase was not present in embryos, but was found in adults in the same zone of the mantle edge as acid phosphatase. Using the enzymes as cell markers, the differentiation of the embryonic shell‐forming tissue to the different zones of the adult mantle edge could clearly be followed.
Foraging strategy switch in detour behavior of the land snail Anguispira alternata (Say)
Authors: Atkinson James W.
Published: August 2010

Abstract. The ability of an olfactory‐dominant organism, the land snail Anguispira alternata, to negotiate an odor‐permeable barrier to obtain food in still air was tested. Thirty‐nine snails were challenged with a “V”‐shaped wire mesh fence that allowed them to get within 1 cm of their food but required them to turn away from the food to move around the fence. Fifteen snails were tested under the same conditions but without a food odor source present. Of the 39 snails tested with food, 22 moved up the odor gradient directly toward the food. Twentyone of these snails altered their foraging behavior by moving away from the odor source after they encountered the barrier. Twelve of these 21 moved along the fence to the food. The other 9 snails moved away from the fence and wandered about within the arena. Of the 39 snails tested, 17 did not move toward the food but by‐passed the fence by either following the arena edge or moving toward the gap between the fence and the arena wall. Since some of these snails obtained the food without encountering the fence, a second experiment challenged 19 snails with a “J”‐shaped fence in which one of the possible detour paths was blocked. There was no difference in the number of snails taking the blocked path vs. snails taking the open path. Therefore it is unlikely that these snails were able to detect the fence and plot a path around it before actually moving. In the 2 experiments, 91% of the snails that followed the odor gradient directly toward the food subsequently switched their foraging behavior. The ability of these snails to switch their foraging behavior was unexpected in an olfactory‐dominant animal and suggests that their behavior is based on a significant amount of sensory processing.
Epidermal ultrastructure and implications for sulfide tolerance in six species of deep‐sea polychaetes
Authors: Menon Jaishri , Willsie Julia K. , Tauscher Andrew , Arp Alissa J.
Published: August 2010

Abstract. Ultrastructural characteristics of the epidermis of 5 deep‐sea vestimentiferan tube worms and an orbiniid worm were similar to those described from other organisms inhabiting sulfidic environments. The integument was composed of a simple or pseudostratified layer of columnar or cuboidal cells, covered by a cuticle of varying thickness, and rested on an extracellular matrix. Unusual mitochondrial morphology was observed in the peripheral region of the epidermis, characterized by an electron‐dense matrix and granules. The abnormal size, shape, and reduced array of cristae in these mitochondria may have resulted from environmental stress. Mitochondria in the inner epidermal layers, where they are more protected from sulfide exposure, displayed normal morphology. The seep vestimentiferans (Seepiophila jonesi and Lamellibrachia cf. luymesi) exhibited numerous electron‐dense organelles, similar in morphology to cytolysosomes and previously described as sulfide oxidizing bodies, while in the 3 vent vestimentiferans (Riftia pachyptila, Tevnia jerichonana, and Oasisia alvinae) and the seep orbiniid Methanoaricia dendrobranchiata, fewer of these organelles were observed. Energy dispersive x‐ray microanalysis of these electron‐dense organelles indicated the presence of sulfur, iron, zinc, and copper, as well as lesser amounts of other elements. We propose that these epidermal cytolysosomes are morphologically similar to previously described sulfide oxidizing bodies that have been hypothesized to play a role in maintaining aerobically poised animal metabolism in sulfide‐enriched habitats.
G protein‐linked receptors and induction of metamorphosis in Bugula stolonifera (Bryozoa)
Authors: Bertrand Jean‐François , Woollacott Robert M.
Published: August 2010

Abstract. Induction of metamorphosis in larvae of the marine bryozoan Bugula stolonifera was examined for potential roles of G protein‐linked cell‐surface receptors. Two compounds that modulate components of the G protein system were tested in a bath‐applied experimental design over concentrations of 10−8 to 10−3 M, plus a seawater control, and 2 controls to assess metamorphic competence (10 mM excess KCl and a biofilmed surface). The G protein activator Gpp[NH]p and the G protein inhibitor GDP‐β‐s did not affect rates of metamorphosis, under the conditions tested. We found no evidence that G protein‐linked cell‐surface receptors are the receptors of the metamorphic cue in this species. This negative finding parallels reports on a gastropod and a polychaete; by contrast, G proteins are involved in metamorphic induction in several cnidarians, a nematode, and barnacles. Thus, as no single model can account for induction across phyla, our results may serve to focus attention on identifying possible roles of the other 2 major classes of cell‐surface receptors in triggering metamorphosis in B. stolonifera and other invertebrates.
Choanoflagellates, choanocytes, and animal multicellularity
Authors: Maldonado Manuel
Published: August 2010

Abstract. It is widely accepted that multicellular animals (metazoans) constitute a monophyletic unit, deriving from ancestral choanoflagellate‐like protists that gave rise to simple choanocyte‐bearing metazoans. However, a re‐assessment of molecular and histological evidence on choanoflagellates, sponge choanocytes, and other metazoan cells reveals that the status of choanocytes as a fundamental cell type in metazoan evolution is unrealistic. Rather, choanocytes are specialized cells that develop from non‐collared ciliated cells during sponge embryogenesis. Although choanocytes of adult sponges have no obvious homologue among metazoans, larval cells transdifferentiating into choanocytes at metamorphosis do have such homologues. The evidence reviewed here also indicates that sponge larvae are architecturally closer than adult sponges to the remaining metazoans. This may mean that the basic multicellular organismal architecture from which diploblasts evolved, that is, the putative planktonic archimetazoan, was more similar to a modern poriferan larva lacking choanocytes than to an adult sponge. Alternatively, it may mean that other metazoans evolved from a neotenous larva of ancient sponges. Indeed, the Porifera possess some features of intriguing evolutionary significance: (1) widespread occurrence of internal fertilization and a notable diversity of gastrulation modes, (2) dispersal through architecturally complex lecithotrophic larvae, in which an ephemeral archenteron (in dispherula larvae) and multiciliated and syncytial cells (in trichimella larvae) occur, (3) acquisition of direct development by some groups, and (4) replacement of choanocyte‐based filter‐feeding by carnivory in some sponges. Together, these features strongly suggest that the Porifera may have a longer and more complicated evolutionary history than traditionally assumed, and also that the simple anatomy of modern adult sponges may have resulted from a secondary simplification. This makes the idea of a neotenous evolution less likely than that of a larva‐like choanocyte‐lacking archimetazoan. From this perspective, the view that choanoflagellates may be simplified sponge‐derived metazoans, rather than protists, emerges as a viable alternative hypothesis. This idea neither conflicts with the available evidence nor can be disproved by it, and must be specifically re‐examined by further approaches combining morphological and molecular information. Interestingly, several microbial lin°Cages lacking choanocyte‐like morphology, such as Corallochytrea, Cristidiscoidea, Ministeriida, and Mesomycetozoea, have recently been placed at the boundary between fungi and animals, becoming a promising source of information in addition to the choanoflagellates in the search for the unicellular origin of animal multicellularity.
Anterior adhesive areas and adjacent secretions in the parasitic flatworms Decacotyle lymmae and D. tetrakordyle (Monogenea: Monocotylidae) from the gills of stingrays
Authors: Cribb Bronwen W. , Whittington Ian D.
Published: August 2010

Abstract. The monogeneans Decacotyle lymmae and D. tetrakordyle (Monocotylidae: Decacotylinae), from gills of the dasyatid stingrays Taeniura lymma and Pastinachus sephen, respectively, have a single aperture for adhesive secretion on each side of the anterior ventrolateral region. Rod‐shaped bodies (S1) and electron‐dense spherical secretion (S2) exit through specialised ducts opening adjacent to one another within these apertures. The S1 bodies are 230 ± 11 nm wide and ≥4 μm long in D. lymmae and 240 ± 9 nm wide and ≥3.3 μm long in D. tetrakordyle. The S2 bodies have a diameter of 88 ± 7 nm in D. lymmae and 65 ± 6 nm in D. tetrakordyle. The apertures are unusual in being extremely small (internal diameter, 3–5 μm). Each aperture has a slit‐like surface opening as small as 160 nm wide, surrounded by muscle fibres indicating that they may be opened and closed. The aperture is also surrounded and underlain by muscle fibres that may aid in secretion from, or even eversion of, the tissue within the aperture. Sensilla/cilia are also found within the apertures. Additional secretions from anteromedian and anterolateral glands (body glands), each containing granular secretions, occur in profusion and exit anteriorly and posteriorly to the position of the apertures, through duct openings in the general body tegument. These granular secretions do not appear to be associated with anterior adhesion. Both species show similarities in aperture, underlying tissue, sense organ, and secretion detail, in accordance with findings from other monogenean genera, and which supports the importance of such data for phylogenetic studies.