464 resultados para Bryozoa.
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Forty-nine species of erect Bryozoa from a broad range of Cyclostome, Ctenostome, and Cheilostome families are described and illustrated, and an artificial dichotomous key is provided for their identification. In general, the marine bryozoan faunas of the northeastern coasts of the United States are poorly known; species records are sparse and voucher collections few, and it is certain that many more species occur in this region than are presently known. The species described here occur in intertidal, coastal or offshore habitats; some are well known and have been recorded on numerous previous occasions, others have been only rarely reported, while a few are known to occur commonly in the north of the region but have yet to be recorded south of Cape Cod. Some of the species described have not been recorded at all on northeastern coasts of the United States, but are widely distributed in North Atlantic continental shelf habitats and perhaps occur in similar parts of the outer shelf of this region. This fauna is thus provisional, but is intended to stimulate further work on the Bryozoa. (PDF file contains 52 pages.)
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The myxozoan, Tetracapsuloides bryosalmonae, exploits freshwater bryozoans as definitive hosts, occurring as cryptic stages in bryozoan colonies during covert infections and as spore-forming sacs during overt infections. Spores released from sacs are infective to salmonid fish, causing the devastating Proliferative Kidney Disease (PKD). We undertook laboratory studies using mesocosm systems running at 10, 14 and 20 degrees C to determine how infection by T bryosalmonae and water temperature influence fitness of one of its most important bryozoan hosts, Fredericella sultana, over a period of 4 weeks. The effects of infection were context-dependent and often undetectable. Covert infections appear to pose very low energetic costs. Thus, we found that growth of covertly infected F. sultana colonies was similar to that of uninfected colonies regardless of temperature, as was the propensity to produce dormant resting stages (statoblasts). Production of statoblasts, however, was associated with decreased growth. Overt infections imposed greater effects on correlates of host fitness by: (i) reducing growth rates at the two higher temperatures: (ii) increasing mortality rates at the highest temperature: (iii) inhibiting statoblast production. Our results indicate that parasitism should have a relatively small effect on host fitness in the field as the negative effects of infection were mainly expressed in environmentally extreme conditions (20 degrees C for 4 weeks). The generally low virulence of T. bryosalmonae is similar to that recently demonstrated for another myxozoan endoparasite of freshwater bryozoans. The unique opportunity for extensive vertical transmission in these colonial invertebrate hosts couples the reproductive interests of host and parasite and may well give rise to the low virulence that characterises these systems. Our study implies that climate change can be expected to exacerbate PKD outbreaks and increase the geographic range of PKD as a result of the combined responses of T. bryosalmonae and its bryozoan hosts to higher temperatures. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.
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Development of a new species of malacosporean myxozoan (Buddenbrockia allmani n. sp.) in the bryozoan Lophopus crystallinus is described. Early stages, represented by isolated cells or small groups, were observed in the host's body wall or body cavity. Multiplication and rearrangement of cells gave an outer cell layer around a central mass. The outer cells made contact by filopodia and established adherens junctions. Sporoplasmosomes were a notable feature of early stages, but these were lost in subsequent development. Typical malacosporean sacs were formed from these groups by attachment of the inner (luminal) cells by a basal lamina to the outer layer (mural cells). Division of luminal cells gave rise to a population of cells that was liberated into the lumen of the sac. Mitotic spindles in open mitosis and prophase stages of meiosis were observed in luminal cells. Centrioles were absent. Detached luminal cells assembled to form spores with four polar capsules and several valve cells surrounding two sporoplasms with secondary cells. Restoration of sporoplasmosomes occurred in primary sporoplasms. A second type of sac was observed with highly irregular mural cells and stellate luminal cells. A radially striated layer and dense granules in the polar capsule wall, and previous data on 18 rDNA sequences enabled assignment of the species to the genus Buddenbrockia, while specific diagnosis relied on the rDNA data and on sac shape and size.
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Plumatella geimermassardi is a newly recognized species of phylactolaemate bryozoan. Its known range extends from Ireland east through southern Norway and south into Italy. Colonies grow close to the substrate with little free branching; the body wall is mostly transparent and without an obvious raphe. Floatoblasts are broadly oval and relatively small, with distinctively large dorsal fenestra and uniformly narrow ventral annulus. The sessoblast basal valve is low and dish-shaped; the annulus bears tubercles which vary in their prominence. This species brings to 14 the number of phylactolaemate bryozoans known in the region.
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The present paper reports on 22 species collected by the Brazilian Program of Living Resources in the Exclusive Economic Zone (REVIZEE). A new genus and species of Cribrilinidae, Corbuliporina crepida n. gen. et sp., is described, along with seventeen other new species: Chaperia brasiliensis n. sp., Amastigia aviculifera n. sp., Isosecuriflustra pinniformis n. sp., Cellaria subtropicalis n. sp., Melicerita brasiliensis n. sp., Arachnopusia haywardi n. sp., Smittina migottoi n. sp., Hippomenella amaralae n. sp., Rogicka joannae n. sp., Malakosaria atlantica n. sp., Turbicellepora winstonae n. sp., Rhynchozoon coalitum n. sp., Stephanollona angusta n. sp., Stephanollona arborescens n. sp., Aulopocella americana n. sp., Conescharellina cookae n. sp. and Conescharellina bocki n. sp. Chorizopora brongniartii (Audouin, 1826) is recorded for the first time in Brazilian waters and a new combination for Rhynchozoon arborescens Canu & Bassler, 1928 is established. New illustrations and taxonomic remarks are included for two little-known species from Brazil, Rogicka scopae (Canu & Bassler, 1928) and Fenestrulina ampla Canu & Bassler, 1928. A compilation of species recorded from deeper waters of the Brazilian coast is included.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This paper includes a reassessment of Scrupocellaria reptans (Linnaeus, 1758) (basionym Sertularia reptans), the lectotype of which is selected and figured from among herbarium-sheet specimens held at the Linnean Society of London. Material previously assigned to S. reptans was examined, providing morphological characteristics to distinguish Scrupocellaria ellisi n. sp. Scrupocellaria reptans has a geographically limited distribution in the United Kingdom, while S. ellisi is more widespread in the North Sea, Northeast Atlantic, Adriatic and Tasmania.
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Background: Bugula is a speciose genus of marine bryozoans, represented by both endemic and cosmopolitan species distributed in tropical and temperate waters and important to marine biologists because of the occurrence of many species in harbor and fouling communities, therefore as potential invaders. The southeastern Brazilian coast in the southern Atlantic hosts the highest known diversity of the genus, a status intimately associated with the intensity of collecting efforts. Methodology: Morphological data based on the examination of living specimens, scanning electron and light microscopic images, and morphometric analyses were used to assess the diversity of Bugula along the coastal areas of southern, northeastern, and southeastern Brazil. In this study, morphological species boundaries were based mainly on avicularian characters. For two morphologically very similar species, boundaries are partially supported by 16 S rDNA molecular data. Results: Nine species are newly described from Brazil, as follows: Bugula bowiei n. sp. (= Bugula turrita sensu Marcus, 1937) from the southern, northeastern, and southeastern coasts; Bugula foliolata n. sp. (= Bugula flabellata sensu Marcus, 1938), Bugula guara n. sp., Bugula biota n. sp. and Bugula ingens n. sp from the southeastern coast; Bugula gnoma n. sp. and Bugula alba n. sp. from the northeastern coast; Bugula rochae n. sp. (= Bugula uniserialis sensu Marcus, 1937) from the southern coast; and Bugula migottoi n. sp., from the southeastern and southern coasts. Conclusion: The results contribute to the morphological characterization and the knowledge of the species richness of the genus in the southwestern Atlantic (i.e., Brazil), through the description of new species in poorly sampled areas and also on the southeastern coast of that country. Additionally, the taxonomic status of the Brazilian specimens attributed to B. flabellata, B. turrita and B. uniserialis are clarified by detailed studies on zooidal and avicularia morphology.
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Among the Scrupocellaria species previously reported from Queensland, three are here redescribed - S. cervicornis, S. curvata and S. diadema; two other species, S. frondis and S. sinuosa, are recorded from the area for the first time; three new species, S. hamata n. sp., S. prolata n. sp. and S. peltata n. sp., are also described, and the remainder are discussed. The need for the re-examination of specimens assigned to this genus is highlighted. The geographic range of some Scrupocellaria species is far more limited than once thought.
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Despite implausible cosmopolitanism, the species Scorpiodinipora costulata (Canu & Bassler, 1929) has been attributed with reservations to small encrusting colonies with similar morphological features whose known distribution is scattered in tropical and subtropical seas: Pacific Ocean (Philippines), Indian Ocean (Oman), Red Sea, SE Mediterranean, SE Atlantic (Ghana) and SW Atlantic (Brazil). This material raised questions about its generic assignment. The genus Scorpiodinipora Balavoine, 1959 is redescribed with Schizoporella costulata Canu & Bassler, 1929, from the Philippines as the type species, as Balavoine misidentified the specimens to define the genus as Cellepora bernardii Audouin, 1826. Moreover, SEM examination of the cotypes of S. costulata showed that Canu & Bassler confused two genera among them. A lectotype and paralectorype were thus chosen from Canu & Bassler's syntypes corresponding with the present morphotype. Hippodiplosia ottomuelleriana var. parva Marcus, 1938, from Brazil, which presents the same morphotype, is provisionally considered as the junior synonym of S. costulata. Considering the broad allopatric distribution of this morphotype across the oceans and the low capacity of dispersal of species with short-lived larvae, it is likely that this material includes several sibling species. However, the role of man-mediated dispersal is not excluded, at least in regions with high shipping activity, such as that comprising the Suez Canal.
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Previous analyses of the mitochondrial gene cytochrome c oxidase subunit 1 (COI) and γ-proteobacterial endosymbiont diversity have suggested that the marine bryozoan Bugula neritina is a complex of three cryptic species, namely Types S, D and N. Types D and N were previously reported to have restricted distributions along California (western USA) and Delaware and Connecticut (eastern USA), respectively, whereas Type S is considered widespread in tropical, subtropical and temperate regions due to anthropogenic transport. Here, Bayesian species delimitation analysis of a data set composed of two mitochondrial (COI and large ribosomal RNA subunit [16S]) and two nuclear genes (dynein light chain roadblock type-2 protein [DYN] and voltage-dependent anion-selective channel protein [VDAC]) demonstrated that Types S, D and N correspond to three biological species. This finding was significantly supported, in spite of the combinations of priors applied for ancestral population size and root age. Furthermore, COI sequences were used to assess the introduction patterns of the cosmopolitan Type S species. Two COI haplotypes of Type S (S1a and S1d) were found occurring at a global scale. Mantel tests showed correlation between these haplotypes and local sea surface temperature tolerance. Accordingly, the distributions of Type S haplotypes may reflect intraspecific temperature tolerance variation, in addition to the role of introduction vectors. Finally, we show that the Type N may also have been introduced widely, as this species was found for the first time in Central California and north-eastern Australia.
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Recent studies of the large cheilostome bryozoan genus Scrupocellaria have shown a greater degree of taxonomically informative morphological variation in zooids, opesia, and polymorphic structures than previously recognized. Only one subgenus has been named within the genus, Retiscrupocellaria d'Hondt, 1988, erected for Scrupocellaria jolloisii. In this work we further analyse S. jolloisii and its related species, resurrecting an earlier genus name, Licornia van Beneden, 1850 for Licornia jolloisii, and nine relatives, L. annectens, L. cervicornis, L. cyclostoma, L. diadema, L. ferox, L. gaspari, L. longispinosa, L. macropora, and L. prolata. Licornia jolloisii was originally described from the Red Sea, and most species of the genus occur in the Indo-Pacific region. The species, however, has now been found in the Western Atlantic, in the Florida Keys, US, and in Bahia de Todos Santos, Brazil.