Bryozoan Species Research Articles

Application of the discordant outlier detection and separation system in the geosciences

Basically, two main types of statistical methods – robust and outlier-based – are available for handling experimental data; we document here the application of the outlier-based method. Due to the unavailability of a suitable software system for statistically correct application of the outlier-based method, a new computer program, DODESSYS (Discordant Outlier DEtection and Separation SYStem), was written for the application of 33 discordancy test variants to experimental data, constituting contaminated or uncontaminated normal statistical samples. We illustrate the application of the discordant outlier-based scheme by five specific examples; three include univariate data for which this procedure was specifically designed and two are for bivariate data for which this methodology can be easily adopted. We thus report new statistical information on two reference materials (granite G-2 and sediment IAEA-417), bryozoan species from eastern Oman, a new improved Na/K geothermometric equation, and a more significant correlation with water depth of the abundance of meiofauna from the Gulf of Mexico. Recently, two sets of multi-dimensional discrimination diagrams for basic as well as acid rocks have been proposed from statistically correct methodology of natural logarithm-transformation of element ratios; the diagrams also require that these ratios should be normally distributed. We present numerous examples of application of these new diagrams for inferring tectonic setting of Archaean to Recent rocks, both before and after testing the datasets for discordant outliers. We recommend that outlying observations should always be evaluated for their discordancy.

Interactions between an invasive and a native bryozoan (Membranipora membranacea and Electra pilosa) species on kelp and Fucus substrates in Nova Scotia, Canada

Most research on biological invasions to date has focused on the population dynamics of very successful and disruptive introduced species; however, additional knowledge of the biology of the native species is essential for understanding interactions between the two and may reveal factors that limit invasion success. The invasive bryozoan Membranipora membranacea interacts with native Electra pilosa on two substrates in northwest Atlantic subtidal habitats: highly dynamic and fast-growing kelps; and smaller, more stable, and slow-growing fucoid algae. We quantified the relative abundance and evaluated encounter outcomes in different seasons of these two bryozoans on kelp and Fucus at four sites in Nova Scotia. We also examined the effects of substrate (kelp, Fucus), temperature (7, 10, 13°C), and food (limited, unlimited) on growth rates of E.pilosa in laboratory experiments and using field manipulations. We compared our findings on factors affecting the growth of E. pilosa to those on M. membranacea obtained in similar and thus directly comparable experiments from a previous study. The proportional abundance of M.membranacea was greater than that of E. pilosa on kelps, but the opposite was observed on Fucus. Competitive standoffs between the two bryozoans were more frequent than expected, with no differences recorded between substrates; most encounters were won by M. membranacea. Growth of E.pilosa was faster on Fucus than kelp, decreased with increasing temperature only on Fucus, and was not affected by food. Growth rate of E. pilosa in all treatments was slower than that previously measured for M.membranacea. Faster growth and strong overgrowth abilities likely interact on kelps to ensure success of the invasive bryozoan. Success can be limited by low space availability, which in turn restricts growth rate, and consequently, colony size, such as on fucoid substrates. The incorporation of alternative contexts into invasion research can reveal factors involved in the resilience of native communities.

Plio-Pleistocene Bryozoan faunas of the Wanganui Basin, New Zealand: stratigraphic distribution and diversity

The New Zealand continental shelf has a rich bryozoan fauna, and Bryozoa are relatively common as fossils in local marine-deposited strata. We record 103 species of Bryozoa occurring in the Wanganui Basin sequence spanning the Plio-Pleistocene (3.0–0.3 Ma), 77 of which belong to the order Cheilostomata and the remainder to the order Cyclostomata. The majority are conspecifics of the modern New Zealand shelf fauna. Palaeoecological characteristics of Wanganui Basin bryozoan faunas including diversity, taxonomic and colony growth-form combinations are identified, defining three biofacies groupings corresponding to depositional sequences (systems tracts). Water depth, sedimentation, substratum characters and taphonomic processes have all influenced the distribution and preservation of bryozoans in the local fossil record. Broader stratigraphic variations in Wanganui Basin faunas are explained by ‘habitat tracking’: a lateral shifting of bryozoan palaeocommunity zones in response to changing environments related to Plio-Pleistocene glacio-eustatic sea-level fluctuations.

Intraspecific variation in larval size and its effects on juvenile lophophore size in four bryozoans

The quantity of maternal investment per offspring is related to maternal fitness and offspring performance. Some models suggest that maximum maternal fitness occurs when mothers produce offspring of a single optimal size (size being a proxy of maternal investment). However, there is substantial intraspecific variation in offspring size, especially in species with lecithotrophic larvae. For most species, the level at which this variation occurs (within vs. among brood) is unclear. We quantified variation in larval size within and among broods for 4 species of bryozoans with lecithotrophic larvae. Larval size was highly variable in all species, and the majority of the variation was found within broods for 3 of the 4 species. In all 4 species, sibling larvae varied up to 2-fold in volume. Further, there were strong positive relationships between initial larval size and juvenile lophophore size for all 4 species. Lophophore size is related to feeding ability, so variation in larval size may result in variation in feeding ability among sibling juveniles. These results offer a probable mechanism for the positive relationship between initial larval size and colony growth rate in bryo zoans.

Redescription of some bryozoan species originally described by J. Jullien from Iberian waters

Six species originally described by Jules Jullien from Iberian waters are redescribed from the original material and stabilized by typification: Caberea ligata, Bicellaria evocata, Scrupocellaria marsupiata, Setosella folini, Euginoma vermiformis and Jubella enucleata. Caberea ligata is placed here in the genus Canda, not previously reported from European waters. Scrupocellaria marsupiata is differentiated from Menipea clausa, previously considered as a junior synonym; both species are placed in the genus Notoplites. A diagnosis is given for the family Jubellidae, the position of which is discussed.

Novel morphological and genetic tools to discriminate species among the family Plumatellidae (Phylactolaemata, Bryozoa)

Some species of the freshwater bryozoans (Bryozoa, Phylactolaemata) belonging to the genus Plumatella are remarkably difficult to identify because of the large similarity of superficial architecture of their statoblasts. The examination of statoblasts by scanning electron microscope (SEM) has in fact resolved only some taxonomic questions. In this article, the authors report on novel morphological and molecular traits to discriminate among ten species of Plumatellidae (P. viganoi, P. repens, P. geimermassardi, P. rugosa, P. reticulata, P. casmiana, P. fungosa, P. emarginata, P. vaihiriae, and Hyalinella punctata). The former traits are based on shape, number, and position of annular chamber pores, whereas the latter reside on amplification and sequence analysis of the Internal Transcribed Spacer (ITS) region of nuclear rDNA. The successful amplification of ITS region from statoblasts and zooidial tubules allowed us to sequence this region on all the species investigated. The ITS sequences showed the presence of sufficient and informative polymorphisms to discriminate among morphologically similar species. It is noteworthy that the resulting ITS phylogenetic tree largely corroborated the distinction of at least two groups of freshwater bryozoans inferred on the basis of the annular chamber pore morphology. This study provides innovative approaches to reliably characterize freshwater bryozoans species and gain more insight into their taxonomy, phylogenetic relationship, and biodiversity.

Freshwater Bryozoa of Okinawa, Japan, with descriptions of Rumarcanella gen. nov. (Phylactolaemata: Plumatellidae) and two new species

We identified nine species of phylactolaemate bryozoans collected from ponds and dams on Okinawa Island, Japan. This is the first report on freshwater bryozoans from Okinawa and includes the first record of Plumatella javanica from Japan. Phylactolaemate species were identified on the basis of colony and statoblast morphology and are illustrated by light microscopy and scanning electron microscopy (SEM). We detected two new plumatellid species that, like Plumatella minuta and Plumatella vorstmani, have a transparent, weakly chitinized colony and hypertubercles on the floatoblast fenestra. A previous molecular study showed these four species to form a clade separate from Plumatella and Hyalinella. We here establish the new genus Rumarcanella to accommodate these species and describe Rumarcanella gusuku n. sp. and R. yanbaruensis n. sp. We discuss the dispersal of bryozoans to and from Japan by birds carrying statoblasts and provide a key to the Phylactolaemata of Japan.

Freshwater Bryozoa of Lake Biwa, Japan

Twelve species of bryozoan (ten phylactolaemates and two ctenostomes) were collected in Lake Biwa and the nearby satellite lakes. Phylactolaemate species were identified by statoblast morphology, and ctenostome species by colony morphology. Fredericellids were the most abundant phylactolaemates in Lake Biwa. Many colonies of Fredericella indica Annandale, 1909, identified by piptoblast morphology, were found in the southern part of the lake. In this genus, only Fredericella sultana (Blumenbach, 1779) had been previously reported from Japan; this is the first report of F. indica. A species of Fredericella having piptoblasts with a tiny, membrane-like ridge at the margin of the valves and weak reticulation on the surface was found in dredge material from the northern part of Lake Biwa; this species is herein described as a new species, Fredericella toriumii. The plumatellid Plumatella fungosa Pallas, 1768 represents an additional new record for Japan. An encrusting ctenostome was identified as a new species, Hislopia prolixa, on the basis of zooid size and morphology, tentacle number, budding pattern, and gut morphology. Hislopia prolixa was also collected from various other localities in Japan. The gut morphology reconstructed in 3D images, zooid morphology, and budding pattern are compared between H. prolixa and several other species of Hislopia. The gut of H. prolixa is larger and the gizzard wall is thicker than in two other species. The budding pattern is similar to that of H. malayensis Annandale, 1916, but accelerated relative to two other species; young buds are already beginning to form the next generation of bud. Some colonies of H. prolixa had many ovaries; the average number was 40 per zooid. Colony morphology suggests that H. prolixa is more closely related to H. cambodgiensis (Jullien, 1880) than to H. natans Woods, Anurakpongsatorn and Mahujchariyawong, 2006.

Late Tortonian bryozoans from Mut Basin, Central Anatolian Plateau, southern Turkey

Sixteen bryozoan species have been identified in the Bayayla section, Mut Basin, southern Turkey. Five of these species are described here, including two new to science representing new genera: Basyaylella elsae gen. et sp. nov. and Ostruvskia trifuramina gen. et sp. nov. The other three described species (Exidmunea sp., Biflustra savartii, and Margaretta sp.) show unusual features that have not been reported previously. Based on bryozoan data, the Bayayla sequence represents a tropical to subtropical, normal marine environment, with seafloor composed of fine sedimentary particles in a low-energy setting.

REDISCOVERYOFA TYPE SPECIMEN OF <i>RETEPORA PLUMA</i> PHILLIPS, 1836, THE TYPE SPECIES OF <i>PENNIRETEPORA</i> D'ORBIGNY, 1849 (FENESTRATA, BRYOZOA), AND REPLACEMENT OF ITS NEOTYPE

REDISCOVERYOFA TYPE SPECIMEN OF <i>RETEPORA PLUMA</i> PHILLIPS, 1836, THE TYPE SPECIES OF <i>PENNIRETEPORA</i> D'ORBIGNY, 1849 (FENESTRATA, BRYOZOA), AND REPLACEMENT OF ITS NEOTYPE

Curation of complex palaeontological objects: a case study of densely encrusted cobbles from a Japanese Pleistocene locality

Fossils most often consist of discrete objects, such as the shell of a brachiopod, or individual bones of a vertebrate skeleton. Cataloging and labelling these specimens is relatively straightforward. However, fossil hard substrates (shells and lithoclasts) with multiple encrustations and borings made by marine organisms can present a greater challenge, as exemplified by material recently collected from a remarkable locality in northern Japan. About 6.5 metres of marine gravels belonging to the Pleistocene Setana Formation, dated at about 1 million years old, are exposed at Kuromatsunai. The well-rounded lithic clasts and associated shells are densely encrusted by well preserved bryozoans and other sclerobionts on all surfaces. Up to 25 different bryozoan species can be found on a single cobble. Full curation of such cobbles is difficult: with little or no free space for affixing labels, how can individual encrusters be indicated and catalogued? Here we present the results of our evaluation of various imaging techniques (microphotography, macrophotography, SEM, 3-D laser scanning etc), and ways of incorporating annotated images into the specimen database (KE EMu) used at the Natural History Museum. A combination of macrophotography and SEM produced the best solution in providing high resolution digital images that could be annotated and uploaded into the KE EMu database.

Sessile and sedentary macrofauna from the Pirapama Shipwreck, Pernambuco, Brazil

Shipwrecks are considered artificial reef environments - structures immersed in aquatic environments (especially marine ones) that provide fauna with shelter, hard substrates, food and nursery areas. This study aimed to survey the benthic animal biodiversity of the Pirapama shipwreck, located 23 m deep and six miles off Recife harbor. From 2001 to 2007, species were observed, photographed and collected through scuba diving. The material was later sorted and identified in the laboratory. A total of 76 sessile and sedentary animal taxa were recorded belonging to the following phyla: Porifera (Demospongiae and Calcarea), Cnidaria (Hydrozoa and Anthozoa), Mollusca (Bivalvia and Gastropoda), Annelida (Polychaeta), Arthropoda (Cirripedia), Bryozoa (Gymnolaemata), Echinodermata (Asteroidea and Echinoidea), and Chordata (Ascidiacea). The greatest richness was for Porifera and Bryozoa - 13 listed species for each. Eleven new occurrences were recorded for the state of Pernambuco, the hydroid Halopteris polymorpha and ten bryozoan species, one of them being the first record for Brazil (Scrupocellaria curacaoensis). The Pirapama's biodiversity was considered typical when compared to other shipwrecks that have been studied around the world.

TREPOSTOME BRYOZOANS FROM THE LOWER - MIDDLE DEVONIAN OF NW SPAIN

The present paper presents descriptions of 11 trepostome bryozoan species from the material deposited at the Geological Centrum Gottingen, Germany, and Nationaal Natuurhistorisch Museum (Naturalis), Leiden, Netherlands. The studied material comes from the Lower to Middle Devonian (Emsian-Eifelian) deposits of different localities in Cantabrian Mountains, NW Spain. Three species are new: Leptotrypella maculata n. sp., Anomalotoechus tabulatus n. sp. and Eifelipora tenuis n. sp. The genus Mongoloclema is reported for the first time from the Devonian of Europe. The described fauna displays palaeobiogeographic relations to the Lower Devonian (Pragian) of Bohemia and to the Middle Devonian of Kazakhstan and Michigan (USA).

Bertorsonidran. gen. (Bryozoa, Cheilostomata) forTremopora prenantiGautier, 1955, a rare species from the Mediterranean

The genus Bertorsonidra n. gen. is here proposed for Tremopora prenanti Gautier, 1955, a cheilostome bryozoan species from the Mediterranean area. The new description and first SEM illustration is mostly based on living material collected from infralittoral (17–19 m) bottoms off W Sicily and fossil specimens from lower Pleistocene, and possibly Pliocene, associations from three different localities in Sicily. The genus and species are characterized by a pseudoporous lepraliomorph frontal shield bordered by marginal areolae, with a prominent suboral umbo; a subcircular primary orifice with a shallow large sinus flanked by condyles, usually protected by oral spines; a prominent ovicell with an entirely exposed calcified entooecium sculptured by tubercles and pseudopores; a lateral suboral, hooked avicularium; and basal calcified pillar-like prominences for adhering to the substratum. The affinities of the genus with Robertsonidra Osburn, 1952, characterized by a frontal shield only perforated by peripheral areolae, are discussed. The erection of the new family Robertsonidridae n. fam. within the Lepraliomorpha is suggested for accommodating both Robertsonidra and Bertorsonidra n. gen. Information is given about ecological requirements of the species, persisting during time, and its morphological adaptation for colonising algal substrata, which Bertorsonidra prenanti n. comb, shares with some species of the genus Robertsonidra and other ones belonging to systematically unrelated genera.

Polymorphism and vestigiality: comparative anatomy and morphology of bryozoan avicularia

Avicularia are polymorphic zooids characteristic of cheilostome bryozoans. Avicularia are assumed to have a defensive role yet ascertaining the presence of sensory structures to support this theory has been overlooked. We examine palatal morphology of the avicularia from five species of cheilostome bryozoans and compare the ultrastructural anatomy of the avicularia from two bugulid species from different habitats. SEM analysis revealed an array of palatal morphologies. Small tufts of cilia emerge from the orifice in the palate of the avicularia of Tricellaria catalinensis, Arachnopusia unicornis and Catenicella pseudoelegans. A ciliated vestigial polypide emerges from the orifice in the palate of Rhynchozoon zealandicum and comprises eleven papillae, or vestigial tentacles, seven of which are covered in microvilli. The vestigial polypide of the bird’s head avicularium of the cosmopolitan Bugula flabellata consists of a mass of ciliated and unciliated cells containing numerous granular vesicles. The avicularium of B. flabellata is capable of detecting tactile stimulation by virtue of the tuft of sensory cilia and is proactive in the capture of invertebrate epibionts. In contrast, in the deep-sea Nordgaardia cornucopioides, the vestigial polypide consists of a ciliated vestigial tentacle encased by glandular secretory cells. Avicularia possess structures derived from a feeding autozooid, and we show how the homologous structures have evolved and suggest that avicularia have been modified to carry out a variety of specific functions.

Algae as hosts for epifaunal bryozoans: Role of functional groups and taxonomic relatedness

Macroalgae build biogenic habitats which give shelter and provide a suitable physical environment for a great variety of organisms. Structural complexity of algal substrates may influence the composition of their attached epifauna. The aim of this study is to test whether the taxonomic relatedness of the algal hosts and the functional groups to which they belong influence the species richness and composition of their epifaunal bryozoans. We analysed 36 algal genera from the Atlantic coast of South America between 42°S and Cape Horn. Changes in bryozoan species richness (number of species) among different algal functional groups (filamentous algae, foliose algae, corticated foliose algae, corticated macrophytes) were non-significant. The composition of the epifaunal assemblages differed significantly only between filamentous and foliose algae. Sheet-like bryozoans (i.e. encrusting, pluriserial colonies) were more frequent on foliose than on filamentous algae, while runner-like species (i.e. uniserial stolons) were characteristic epibionts on filamentous thallii. Similarity of bryozoan assemblages increased with increasing taxonomic relatedness of their hosts. As most filamentous seaweeds analysed in this study are members of the Order Ceramiales, the influence of algal taxonomic relatedness and functional groups on the composition of their bryozoan assemblages can be viewed as two different aspects of the same phenomenon.

The Composition of fatty acids and aldehydes of the marine bryozoans Berenicea meandrina and Dendrobeania flustroides (Bryozoa: Gymnolaemata)

This study examines the composition of lipids, fatty acids, and fatty aldehydes in two marine bryozoan species, Berenicea meandrina and Dendrobeania flustroides, from the Sea of Okhotsk. The share of neutral lipids was up to 57.3% in D. flustroides and 54.9% in B. meandrina; the share of polar lipids was 33.2 and 40.4%, respectively. In all, 57 fatty acids (FA) and 9 aldehydes were identified in total lipids. The main FAs were 16:0, 18:0, 22:6n-3, and 20:5n-3. The content of branched saturated FA in bryozoans was on the average 6.4%. Three isomers of 16:1 (n-9, n-7, and n-5), five isomers of 18:1 (n-13, n-11, n-9, n-7, and n-5), four isomers of 20:1 (n-13, n-11, n-9, and n-7), as well as 22:1n-9 and 22:1n-13 were found; the presence of 7-methyl-6-hexadienoic acid (on the average, 3.0% of total FAs) was demonstrated. Non-methylene-inter-rupted FAs contributed 8.9 and 1.6% of the total FAs in D. flustroides and B. meandrina, respectively, and were identified as 20:2(5,11), 20:2(7,13), 20:3(5,11,14), 22:2(7,13), and 22:2(7,15). In B. meandrina, minor amounts of 24:0, 24:1, 25:0, 26:0, 24:4n-3, 26:3(5,9,19), and 28:3(5,9,19) were found, suggesting sponge biofouling on some bryozoan colonies. Aldehydes (branched saturated and unsaturated C16–19 homologues) did not exceed 10.3 and 1.9% of the total FAs in D. flustroides and B. meandrina, respectively. The presence of the FA markers that are characteristic of microalgae, protozoans, and detritus in bryozoan lipids agrees well with data on polytrophic feeding of these bryozoans.

Phylogenetic diversity and antimicrobial activities of bryozoan-associated bacteria isolated from Mediterranean and Baltic Sea habitats

To date, only a small number of investigations covering microbe–bryozoa associations have been carried out. Most of them have focused on a few bryozoan species and none have covered the antibacterial activities of associated bacteria. In the current study, the proportion and phylogenetic classification of Bryozoan-associated bacteria with antimicrobial properties were investigated. Twenty-one specimens of 14 different bryozoan species were collected from several sites in the Baltic and the Mediterranean Sea. A total of 340 associated bacteria were isolated, and 101 displayed antibiotic activities. While antibiosis was predominantly directed against Gram-positive test strains, 16S rRNA gene sequencing revealed affiliation of the isolates to Gram-negative classes ( Flavobacteria, Alpha- and Gammaproteobacteria). One isolate was related to the Gram-positive Actinobacteria. The sequences were grouped into 27 phylotypes on the basis of similarity values ≥99.5%. A host-specific affiliation was not revealed as members of the same phylotype were derived from different bryozoan species. Site-specific patterns, however, were demonstrated. Strains of the genera Sphingomonas and Alteromonas were exclusively isolated from Mediterranean sites, whereas Shewanella, Marinomonas and Vibrio-related isolates were only from Baltic sites. Although Pseudoalteromonas affiliated strains were found in both habitats, they were separated into respective phylotypes. Isolates with 16S rDNA similarity values <98%, which could possibly represent new species, belonged to the genera Shewanella, Pseudoalteromonas and Tenacibaculum.

A new species of Polyzoa (Ascidiacea: Styelidae) from the Atlantic coast of N America, U. S. A.

A new species of Polyzoa (Ascidiacea: Styelidae) from the Atlantic coast of N America, U. S. A.

Baudina' gen. nov., Constituting the First Record of Pasytheidae from Australia, and Sinoflustridae fam. nov., with a Checklist of Bryozoa and Pterobranchia from Beagle Gulf

'Baudina' gen. nov., comprising two new species from the Beagle Gulf of Australia's Northern Territory, is the first pasytheid bryozoan to be recorded from Australian continental waters. Colonies are wholly encrusting, forming uni- to triserial ramifying colonies. The zooids have the largest gymnocystal perforations of any other pasytheid, living or fossil. The new 'Baudina' taxa constitute two of 84 bryozoan species so far known from Beagle Gulf, including Darwin Harbour. 'Sinoflustra' Liu and Yang, 1995, a genus of uncertain affinity, is herein designated the type species of a new family, Sinoflustridae, which also includes 'Membraniporopsis' Liu in Liu, Yin and Xia, 1999. The bryozoan diversity of Beagle Gulf is small relative to what may be expected of tropical Indo-Pacific bryozoans for an area this size and it is likely that several hundred more species will be discovered upon further dedicated sampling.