Bryozoan Species Research Articles

A broadly resolved molecular phylogeny of New Zealand cheilostome bryozoans as a framework for hypotheses of morphological evolution

Larger molecular phylogenies based on ever more genes are becoming commonplace with the advent of cheaper and more streamlined sequencing and bioinformatics pipelines. However, many groups of inconspicuous but no less evolutionarily or ecologically important marine invertebrates are still neglected in the quest for understanding species- and higher-level phylogenetic relationships. Here, we alleviate this issue by presenting the molecular sequences of 165 cheilostome bryozoan species from New Zealand waters. New Zealand is our geographic region of choice as its cheilostome fauna is taxonomically, functionally and ecologically diverse, and better characterized than many other such faunas in the world. Using this most taxonomically broadly-sampled and statistically-supported cheilostome phylogeny comprising 214 species, when including previously published sequences, and 17 genes (2 nuclear and 15 mitochondrial) we tested several existing systematic hypotheses based solely on morphological observations. We find that lower taxonomic level hypotheses (species and genera) are robust while our inferred trees did not reflect current higher-level systematics (family and above), illustrating a general need for the rethinking of current hypotheses. To illustrate the utility of our new phylogeny, we reconstruct the evolutionary history of frontal shields (i.e., a calcified body-wall layer in ascus-bearing cheilostomes) and ask if its presence has any bearing on the diversification rates of cheilostomes.

Early Miocene coral reef-associated bryozoans from Colombia. Part I: Cyclostomata, “Anasca” and Cribrilinoidea Cheilostomata

AbstractThis is the first of two comprehensive taxonomic works on the early Miocene (ca. 23–20 Ma) bryozoan fauna associated with coral reefs from the Siamaná Formation, in the remote region of Cocinetas Basin in the La Guajira Peninsula, northern Colombia, southern Caribbean. Fifteen bryozoan species in 11 families are described, comprising two cyclostomes and 13 cheilostomes. Two cheilostome genera and seven species are new:Antropora guajirensisn. sp.,Calpensia caribensisn. sp.,Atoichos magnusn. gen. n. sp.,Gymnophorella hadran. gen. n. sp.,Cribrilaria multicostatan. sp.,Cribrilaria nixorn. sp., andFigularia bragain. sp. Eight species are identified only at genus level and remain in open nomenclature. Of the species found, 27% have erect colonies and 73% encrusting colonies. Both types contributed to the reef framework and produced sediment. The observed bryozoan diversity was higher in the barrier reefs than in the lagoonal patch reefs.UUID:http://zoobank.org/5c8468ef-31b0-4e7e-ba93-60a2e2f30b76.

Morphology of ctenostome bryozoans: 4. Pierrella plicata.

The genus Pierrella was originally created for a single fossil ctenostome bryozoan species from the Late Cretaceous, which is characterized by runner‐like colonies, with zooids possessing a distinctive radial, folded aperture. Not long ago, a few specimens of a recent deep‐sea congener, Pierrella plicata, were discovered and described from the Russian exploration area of the Clarion‐Clipperton Fracture Zone, eastern Central Pacific Ocean. Owing to the lack of data on the internal morphology of this species, we investigated the soft‐body morphology of P. plicata using serial sectioning and 3D‐reconstruction in order to compare it to other more recently investigated ctenostome bryozoans and to infer the systematic position of the genus. The most striking peculiarity of the examined species is the radial aperture formed by multiple cuticular, pleated folds of the cystid wall. The cuticle is thickened into triangular‐shaped folds in this area. An orifical sphincter underlies the folded aperture. Apertural muscles are present as a single pair of parieto‐diaphragmatic muscles and four duplicature bands. The remaining polypide anatomy is mainly characterized by its miniature design: the lophophore has eight short tentacles and the digestive tract is one of the shortest and most compact ever observed in any bryozoan. A small intertentacular organ was detected at the lophophoral base. Taken together the genus Pierrella shows unique characters, such as the radial apertural folds that are closed by a series of orificial sphincter muscles, and its particularly small polypide. The general colony morphology resembles arachnidioidean ctenostomes whereas its internal morphology resembles alcyonidioidean species.

Caupokeras badalloi, a new ichnospecies of impedichnia from the Lower Devonian of Spain. Palaeoecological significance

ABSTRACT A new ichnospecies, Caupokeras badalloi, is here erected from the Emsian (Lower Devonian) Aguión Formation of Asturias, NW Spain. It is a bioclaustration structure produced by the host-specific symbiotic intergrowth of two host bryozoan species, Leioclema elegans and Loxophragma cf. leptum, and a soft-bodied modular symbiont, possibly a hydroid. The distinctiveness of this bioclaustration structure creates the need for a new ichnotaxonomic name. The settlement and development of the symbiont on living colonies of bryozoan hosts formed sets of tubes with terminal openings that do not occur in non-symbiotic bryozoans, thus modifying the normal growth of its living substrate. Consequently, C. badalloi n. isp. is considered herein as belonging to the ethological category of impedichnia in the absence of a universally accepted criterion on the status of bioclaustration structures. The diagnosis of the ichnogenus Caupokeras is emended.

Developmental Process of a Heterozooid: Avicularium Formation in a Bryozoan, Bugulina californica.

In bryozoans (phylum Bryozoa), representative colonial animals mostly found in marine environments, some species possess different types of individuals (heterozooids) specialized in different functions such as defense or structural support for their colonies. Among them, the best-known heterozooids are the avicularia, known to function as defenders. The differentiation processes of heterozooids, including avicularia, should be important keys to understand the evolutionary significance of bryozoans. However, the developmental process of avicularium formation remains to be fully understood. In this study, therefore, in order to understand the detailed developmental process and timing of avicularium formation, extensive observations were carried out in a bryozoan species, Bugulina californica (Cheilostomata, Bugulidae), that possesses adventitious avicularia, by performing stereomicroscopy on live materials, in addition to scanning electron microscopy and histological observations. The whole process can be divided into seven stages based on developmental events. Especially notably, at the earlier stages, there are three major budding events that produce proliferating cell masses corresponding to primordial tissues: (1) budding of the peduncle cushion at the outer margin of the distal part of a young autozooid, (2) budding of the head-part primordium from the peduncle cushion, and (3) budding of the polypide inside the head part. Experimental control of temperature showed that 20°C would be the best to maintain B. californica colonies.

Hitchhiking of encrusting organisms on floating marine debris along the west coast of Qatar, Arabian/Persian Gulf.

The floating marine debris (FMD) and the associated rafting communities are one of the major stressors to ecosystem services, global biodiversity and economy and human health. In this study, assemblages of encrusting organisms on different types of stranded FMD along the west coast of Qatar, Arabian/Persian Gulf (hereafter referred to as 'Gulf') were examined. The analysis showed 18 fouling species belonging to 5 phyla (Annelida, Anthropoda, Bryozoa, Mollusca and Porifera) on the FMD. The most abundant fouling species were the encrusting Amphibalanus amphitrite, polychaete Spirobranchus kraussii, Bryozoan species and Megabalanus coccopoma. More number of taxa were found on larger size FMD than on smaller FMD. Some of the barnacle rafting types were found to be non-indigenous species. The central and northwest parts of the Qatar had more FMD and fouled species than in other locations. Winds and the prevailing hydrodynamic conditions (waves and currents) played an important role in the transportation and distribution of FMD and associated organisms along the west coast of Qatar. The present study confirmed that huge amount of bio-fouled FMD items, causing great damage to biodiversity, drift in the surface layer of ocean and eventually strand onto the beaches. We propose a simple, but an effective management plan for FMD and associated organisms at regional scale to restore the biodiversity, sustainability and health of the marine ecosystem in the Gulf.

Molecular data suggest the worldwide introduction of the bryozoan Amathia verticillata (Ctenostomata, Vesiculariidae)

The arborescent bryozoan Amathia verticillata (Delle Chiaje, 1822) can be found in both tropical and temperate waters but little is known on how natural dispersal and human-mediated transport mediates its current widespread distribution. The species can rapidly cover and dominate large areas of natural and artificial substrates, and infests port areas, ships, pipelines, and industrial marine installations. In addition, A. verticillata could be a complex of cryptic species, similar to many other bryozoan species with presumed cosmopolitan distributions. In this study, we tested whether A. verticillata represents a complex of cryptic species or it is a single species, and assessed whether natural and/or anthropogenic dispersal can explain its cosmopolitan distribution. We performed phylogenetic and population genetic analyses based on two mitochondrial genes (16S and COI) from samples collected in the United States, Brazil, Spain, Australia, and Mexico. Our results show a low genetic structure between Atlantic and Pacific oceans, with one haplotype of both genes widely distributed, while the other haplotypes (all with very low nucleotides diversity) were specific to each region. This suggests that A. verticillata is a single species, whose broad distribution seems to have been mediated by humans; the biology of the species in addition to its common occurrence near port areas also indicate this fact. However, to elucidate its origin and dispersal routes, a more extensive sampling effort and the usage of the genome-wide molecular markers should be explored. Until these studies are carried out, we recommend that the species should still be considered as cryptogenic.

Bryozoan assemblages on gastropod shells occupied by the hermit crab Pagurus comptus

Bryozoans are common on gastropod shells inhabited by the hermit crab Pagurus comptus in the southern southwest Atlantic. The aim of this study was to test whether bryozoan biodiversity was higher on larger and more complexly sculptured gastropod shells, as well as to analyze spatial and bathymetric changes in bryozoan assemblages. Forty-four bryozoan species were recorded on 59 gastropod (morpho) species. Larger shells tended to host a higher number of bryozoan species than smaller ones. Bryozoan species richness differed significantly among gastropods with different shell ornamentation, but richness did not increase along a predicted qualitative scale of increasing ornamentation complexity. Almost smooth but large shells had a much higher bryozoan richness than expected, and small shells with prominent ornamentation had unexpectedly the lowest richness, suggesting that shell size may be more important than ornamentation in determining bryozoan richness. Most of the shells hosted two bryozoan species, although up to 11 species per shell were observed. Maximum bryozoan richness occurred between 99 and 137 m. Bryozoan species richness on gastropod shells occupied by P. comptus was higher in the Burdwood Bank than around Tierra del Fuego and Isla de los Estados. Epibiont assemblage composition and species richness differed among the six most abundant gastropods (Trophon ohlini, Pareuthria atrata, Cerithiopsis caelatum, Fuegotrophon pallidus, P. fuscata, Argeneuthria cerealis). The two most abundant bryozoans, Burdwoodipora paguricola and Odontoporella adpressa, do not overlap in their occupation of shell surfaces. This is the first study analyzing the relationships among bryozoans, gastropod shells, and hermit crabs in subantarctic waters.

Effective detection methods for Pectinatella magnifica Leidy 1851 colony distribution using statoblasts

A rapidly expanding range of Pectinatella magnifica has been reported globally. Although many studies have been conducted to manage this invasive species, surveying methods have mainly been limited to visual observation of bryozoan colonies. For efficient monitoring and early detection of bryozoan species, we compared three different monitoring methods: visually detecting bryozoan colonies (visual observation of colonies, VOC), floating statoblasts (statoblasts in filtered water, SFW), and attached statoblasts (statoblasts attached to artificial substrate, SAS). Using these sampling methods, we compared the occurrences of P. magnifica in the littoral zones of lotic ecosystems from 117 sites in South Korea from 2015 to 2019. Occurrence frequency of P. magnifica was higher using both SFW (37.3%) and SAS (72.5%) than the traditional VOC (28.0%) method. The agreement of occurrence detection of P. magnifica between VOC, SFW and SAS was more consistent in tributaries than in main channels. Density estimations using colony (VOC) and statoblast detection methods (SFW, SAS) also showed a higher positive correlation in tributaries. To identify early P. magnifica invasion in an unidentified area, collecting statoblasts is a more efficient alternative to determine the occurrence of bryozoan species in field conditions.

A checklist of ciliate epibionts (Ciliophora) found on bryozoans.

A compilation of the ciliate (Ciliophora) species found on marine and fresh water bryozoans as epibionts has been carried out based on published records. The checklist includes the taxonomic position of each species of epibiontic ciliate, the species of basibiont bryozoans, localities and the bibliographic references. Altogether 40 ciliate species from classes Spirotrichea (two species); Suctorea (sixteen species); Oligohymenophorea, subclass Peritrichia (sixteen species) and Heterotrichea, family Folliculinidae (six species) were listed. Among registered species, six were reported on bryozoans only. Only one species of peritrich ciliate Ellobiophrya conviva adapted to inhabit on tentacles of bryozoans with special adhesive organelle (cinctum or adhesive ring) indicate a possible specific to bryozoan host.

BRYOZOAN FAUNA FROM THE OOLITIC LIMESTONE FROM PAJAREJOS, SW SPAIN

Outcrops of Devonian rocks at the hill of Pajarejos near Campillo de Llerena, south-western Spain, expose oolitic limestone which contains abundant fragments of bryozoans, whereas other macrofauna is scarce. Eight bryozoan species were identified, which date the outcrop as Middle Devonian. The assemblage shows close affinities with that described from Sabkhat Lafayrina reef complex in Western Sahara, which is situated more than 1,000 km further south today. The studied association supports the previously proposed hypothesis that South-western Spain belonged to the northern margin of Gondwana during the Middle Devonian.

Sharing and Distinction in Biodiversity and Ecological Role of Bryozoans in Mediterranean Mesophotic Bioconstructions

Bryozoan assemblages of three mesophotic habitats, recently found in the Adriatic and Ionian Seas, were investigated in terms of species composition and diversity, colonial growth forms, and species ecological affinity, with the purposes to analyze variations and similarities between the different bioconstructions and to compare the mesophotic assemblages with those of other benthic habitats. Bryozoans came from three sites off the Apulian coast: Monopoli, 30–55-m depth, where scleractinians are dominant; Otranto, 45–64-m depth; and Santa Maria di Leuca, 45–70-m depth, where the bivalve Neopycnodonte cochlear is the main bioconstructor. A total number of 50 species of bryozoans were recorded, accounting for about 10% of the total number of Mediterranean species. Only few species were shared between the three sites, whereas a considerable pool of species was characteristic of each site. The β-diversity and Sörensen similarity analyses highlighted the highest similarity between the two southern sites, Otranto and Santa Maria di Leuca, with respect to the northern site of Monopoli, in agreement with the hydrological pattern of the area. The encrusting zoarial type was the most abundant in each site, and few species with erect, celleporiform and petraliform colonies were found. The Sörensen similarity, based on data of zoarial forms composition, revealed values considerably higher than those based on species composition, thus highlighting the similar ecological role played by the bryozoans in all the sites. Moreover, significant differences between the mesophotic bryozoan assemblages and those of other benthic Mediterranean habitats were highlighted, showing higher affinity with the coralligenous and detritic sciaphilic habitats. The relevant ecological role of bryozoans as binders in the bioconstructions of the Mediterranean mesophotic zone has been exhibited.

Bryozoans from the lower Silurian (Telychian) Hanchiatien Formation from southern Chongqing, South China

AbstractEight bryozoan species are described from the Hanchiatien Formation (lower Silurian, Telychian) of southern Chongqing, South China. Four species are new: the trepostomesAsperopora sinensisn. sp.,Trematopora jiebeiensisn. sp., andTrematopora tenuisn. sp., and the fenestrateMoorephylloporina parvulan. sp. One species, the cystoporateHennigoporasp. indet., is described in open nomenclature.Moorephylloporina parvulan. sp. is eurytopic, occurring in all types of facies within the bioherms. ErectMoorephylloporinaBassler, 1952,TrematoporaHall, 1852, andLeioclemaUlrich, 1882 formed pioneering communities on weakly cemented substrata, whereas encrustingFistuliporaM‘Coy, 1849,HennigoporaBassler, 1952, andAsperoporaOwen, 1969 occurred on hardgrounds and formed densely compact framestones. Robust branchedTrematoporaandLeioclematend to occur out of the reef core (framework) where they could have formed reef-flank thickets in more agitated conditions. The generic composition of the studied fauna correlates with other localities in South China, and they show general paleobiogeographic relations to Siberia and Indiana, USA.UUIDhttp://zoobank.org/3326dd2f-7c9e-43bc-9dab-84047b274f89

Summer and winter MgCO3 levels in the skeletons of Arctic bryozoans

In the Arctic, seasonal patterns in seawater biochemical conditions are shaped by physical, chemical, and biological processes related to the alternation of seasons, i.e. winter polar night and summer midnight sun. In summertime, CO2 concentration is driven by photosynthetic activity of autotrophs which raises seawater pH and carbonate saturation state (Ω). In addition, restriction of photosynthetic activity to the euphotic zone and establishment of seasonal stratification often leads to depth gradients in pH and Ω. In winter, however, severely reduced primary production along with respiration processes lead to higher CO2 concentrations which consequently decrease seawater pH and Ω.Many calcifying invertebrates incorporate other metals, in addition to calcium, into their skeletons, with potential consequences for stability of the mineral matrix and vulnerability to abrasion of predators. We tested whether changes in seawater chemistry due to light-driven activities of marine biota can influence the uptake of Mg into calcified skeletons of Arctic Bryozoa, a dominant faunal group in polar hard-bottom habitats. Our results indicate no clear differences between summer and winter levels of skeletal MgCO3 in five bryozoan species despite differences in Ω between these two seasons. Furthermore, we could not detect any depth-related differences in MgCO3 content in skeletons of selected bryozoans. These results may indicate that Arctic bryozoans are able to control MgCO3 skeletal concentrations biologically. Yet recorded spatial variability in MgCO3 content in skeletons from stations exhibiting different seawater parameters suggests that environmental factors can also, to some extent, shape the skeletal chemistry of Arctic bryozoans.

Species richness and the level of knowledge of the bryozoan fauna of the Arctic region

The publication presents the results of the analysis of retrospective data and samples of bryozoans collected in different seas and areas of the Arctic region during recent 30 years. To date, 518 species of bryozoans have been recorded in the Arctic, which is on 26.4% more than previously registered. The level of increase in species numbers in the species lists of the regional faunas was different in different areas. In the waters of Greenland, the found species diversity of bryozoans was on 12% higher; in the Barents and Kara Seas – on 18 and 19%, respectively; in the Laptev and East Siberian seas – on 30%; in the Faroe Islands waters on 30% than it was previously marked. In the Icelandic waters and the Chukchi Sea, the number of bryozoan species is richer by five and two times respectively than it was considered earlier. Our assessment of the modern knowledge of the fauna of this group using the method of rarefaction showed that the bryozoan fauna is still underexplored. The Chao metric calculations also indicate that expected species richness would increase by 10–30% in different areas of the Arctic in case of additional sampling efforts. At the same time, a measure of taxonomic distinguish of the fauna allows to conclude that the species composition of bryozoans has already been sufficiently studied in most of the considered areas of the Arctic zone except in the waters of the Canadian Arctic Archipelago.

Natural chemical control of marine associated microbial communities by sessile Antarctic invertebrates

Organisms living in the sea are exposed to fouling by other organisms. Many benthic marine invertebrates, including sponges and bryozoans, contain natural products with antimicrobial properties, since microbes usually constitute the first stages of fouling. Extracts from 4 Antarctic sponges (Myxilla (Myxilla) mollis, Mycale tylotornota, Rossella nuda, and Anoxycalyx (Scolymastra) joubini) and 2 bryozoan species (Cornucopina pectogemma and Nematoflustra flagellata) were tested separately for antifouling properties in field experiments. The different crude extracts from these invertebrates were incorporated into a substratum gel at natural concentrations for an ecological approach. Treatments were tested by submerging plates covered by these substratum gels under water in situ during 1 lunar cycle (28 d) at Deception Island (South Shetland Islands, Antarctica). Remarkably, the butanolic extracts of M. tylotornota and C. pectogemma showed complete growth inhibition of microscopic eukaryotic organisms, one of the succession stages involved in biofouling. Our results suggest that different chemical strategies may exist to avoid fouling, although the role of chemical defenses is often species-specific. Thus, the high specificity of the microbial community attached to the coated plates seems to be modulated by the chemical cues of the crude extracts of the invertebrates tested.

A New Bryozoan of the Genus Dianulites Eichwald from the Ordovician of Gorny Altai and the Russian Arctic

A new bryozoan species Dianulites altaicus sp. nov. (order Esthonioporata) is described from the Sandbian Stage of the Upper Ordovician of the environs of Lake Teletskoe in Gorny Altai. A collection of bryozoans of the genus Dianulites Eichwald, 1829 from the Lower and Middle Ordovician of the Novaya Zemlya archipelago and Vaygach Island in the Russian Arctic has been revised. Bryozoans from the Lower and Middle Ordovician of the Novaya Zemlya archipelago previously classified as D. janischevskyi Modzalevskaya, 1953 were shown to belong to D. altaicus sp. nov. Two groups of species of the genus Dianulites have been identified in the Ordovician of the Russian Arctic: the representatives of the first group had mesozooecia, whereas the representatives of the second group, which includes the new species, did not have mesozooecia, but some of them had minutopores.

Effect of removal of organic material on stable isotope ratios in skeletal carbonate from taxonomic groups with complex mineralogies.

Stable oxygen and carbon isotope ratios are one of the most accurate ways of determining environmental changes in the past, which are used to predict future environmental change. Biogenic carbonates from marine organisms are the most common source of samples for stable isotope analysis. Before they are analyzed by mass spectrometry, any organic material is traditionally removed by one of three common pretreatment methods: roasting, bleaching, or with hydrogen peroxide at various strengths and durations. This study compares δ18 O and δ13 C values in a control with no pretreatment with those from five different pretreatment methods using conventional acid digestion mass spectrometry. The objectives are to: assess the impact of the most common pretreatment methods on δ18 O and δ13 C values from (1) taxonomically underrepresented groups in previous studies, and (2) those that precipitate a wide range of biomineralogies, in the debate of whether to pretreat or not to pretreat. We analyzed the following biomineralogically complex temperate marine organisms from southern New Zealand: four species of bryozoans, four species of molluscs, two species of arthropods, and one species each of annelid, red alga, brachiopod, and echinoderm (test plates and spines treated separately). These species precipitate aragonite, High-, Intermediate-, and/or Low-Mg calcite (LMC) in their skeletons. We used linear mixed statistical models to compare the effects of the pretreatments and mineralogical composition on their δ18 O and δ13 C values. Roasting was the most effective pretreatment for the removal of organic matter and light H2 O2 the least, but the former had corresponding impacts on isotope ratios. δ18 O values were not directly affected by wt% MgCO3 , but they were significantly affected by the interaction of roasting and wt% MgCO3 . This same negative effect of roasting on species with higher wt% MgCO3 occurred in δ13 C values, but it was much more pronounced in δ18 O values. Both H2 O2 pretreatments significantly and negatively affected δ18 O values at higher wt% MgCO3 . Neither bleaching pretreatment significantly affected δ18 O values. δ13 C values were most negatively affected in skeletons with high wt% MgCO3 . There was also a strong negative roasting effect and more so at higher wt% MgCO3 . Bleaching and H2 O2 did not significantly affect δ13 C values. Based on these results, and when using skeletal carbonate of complex mineralogies, we recommend considering the abandonment of pretreatment of biogenic carbonate for stable isotope analysis due to confounded results from previous studies, difficulties with preparation, and/or the absence of significant effects of organic material on isotope ratios. If pretreatment is necessary, avoid roasting especially at higher temperatures and durations, use minimal bleaching, and in general avoid using High-Mg calcite species in O and C stable isotope studies. If bleaching is used, clearly indicate the concentration and duration of exposure.

Two new steroid sulfates from a cheilostome bryozoan, Calyptotheca sp.

Two new steroid sulfates 1 and 2 were obtained from a lipophilic extract of an undescribed bryozoan species in the genus Calyptotheca. The structures of compounds 1 and 2 were elucidated by spectroscopic methods and chemical modifications. Steroids 1 and 2 exhibited moderate cytotoxicity at IC50 54 and 30 µM, respectively, against NBT-T2 cells.

Novel taxa of Cheilostomata Bryozoa discovered in the historical backlogs of the Iziko South African Museum

Non-studied museum collections are hidden treasures-a source of information for various research fields. The novel taxa presented here were discovered during taxonomic examination of the backlogs of Bryozoa (Cheilostomata) from the Iziko South African Museum. We describe one new genus, Khulisa n. gen., and nine new species of bryozoans from South Africa. The new species are: Biflustra adenticulata n. sp., Aspidostoma sarcophagus n. sp., ?Micropora erecta n. sp., Trypostega richardi n. sp., Khulisa carolinae n. gen. et n. sp., Adeonella assegai n. sp., Hippomonavella lingulata n. sp., Phidolopora chakra n. sp. and Reteporella ilala n. sp. Three genera, Biflustra, Phidolopora and Triphyllozoon, are recorded for the first time from South Africa. This study highlights the importance of examining existing backlogged material lodged in museum collections.