ASCIDIAN NEWS*

Gretchen and Charles Lambert

12001 11th Ave. NW, Seattle, WA 98177

206-365-3734

glambert@fullerton.edu or clambert@fullerton.edu

home page:  http://depts.washington.edu/ascidian/

 

Number 67                                                                                                                                                                 December 2010

 

Thanks so much to all of you who sent in the many contributions to this issue; it is gratifying to know that AN is still an important resource. We also enjoy hearing from you. There are 115 new publications listed at the end of this newsletter, many abstracts from recent meetings, announcements of upcoming meetings in 2011, and much more! We hope you find it useful and interesting.

   We spent most of June and July at the Friday Harbor labs where Gretchen continued her work on the Pacific distribution of the Atlantic Molgula citrina (Aquatic Invasions 5 (4): 369-378) and Charley worked on aspects of germinal vesicle breakdown in Boltenia villosa oocytes. In late July we joined a team of biologists on a rapid assessment survey for invasive marine species in New Hampshire, Maine, Mass. and Rhode Island. The RAS was organized by Judy Pederson and Jan Smith from Mass. Sea Grant and Coastal Zone Management. In September we attended the Invertebrate Fertilization meeting at the Friday Harbor Labs organized by Steve Stricker and  Gary Wessels. Charley presented a paper on Boltenia GVBD.  In October we joined a survey group from Oregon State University organized by John Chapman. On this RAS we investigated ascidians on solid substrates in Coos Bay, Newport Bay and elsewhere along the coast. We were surprised to see large numbers of Corella inflata in Coos Bay where we had never seen more than a few, and a large number of the Atlantic Molgula citrina. The newsletter is a bit late this time because December has taken us to Sacramento, California where Charley is undergoing medical treatment, but we are greatly enjoying our new granddaughter Alise.

 

*Ascidian News is not part of the scientific literature and should not be cited as such.

 

NEWS AND VIEWS

 

1. The next Ascidian Workshop will be held at the Panama Bocas del Toro Smithsonian Tropical Research Institute June 9-30, 2011.

Pan American Advanced Studies Institute (PASI): Advanced Tunicate Biology: Integrating Modern and Traditional Techniques for the Study of Ascidians

Notice that this is a 3 week workshop, which will include:

  • Lectures on recent advances in ascidian taxonomy
  • Identification and systematics, with plenty of hands-on lab time and field collecting. We will be using keys to the families and genera of the world
  • Training in methods for DNA barcoding
  • Modern imaging and bioinformatics approaches to curation of samples
  • Lectures on symbiosis, chemical ecology, evo-devo, and invasion biology
  • Lectures on basic physiology and developmental biology, which are necessary to a full understanding of ascidian biology
  • Demonstrations on obtaining and fertilizing gametes from a wide variety of solitary and colonial species, and starting cultures in the laboratory

The following link gives background information on the participating experts:
http://striweb.si.edu/taxonomy_training/future_courses/2011/2011_PASI_atp_Experts.html

For more information, go to the following link:
http://striweb.si.edu/taxonomy_training/future_courses/2011/2011_PASI_Advanced_Tunicate_Biology.html
and click on the Download PDF link (4.36mb).

2. From Ken Hastings, Montreal Neurological Institute, McGill University, Montreal, Quebec,

Canada  ken.hastings@mcgill.ca

    The Sixth International Tunicate Meeting will be held in Montréal, Québec, Canada, at McGill University, July 3-7, 2011.

   Abstracts may be submitted describing any aspect of tunicate research, such as developmental biology, regeneration, genomics, genetics, cell biology, physiology, neurobiology, biochemistry, allorecognition, evolution/systematics, ecology.  Abstracts describing research on tunicates as invasive species are welcome as this will be a topic of special interest at this meeting (see #5 below from Mary Carman). In addition, abstracts describing research on other organisms that sheds light on deuterostome evolution and chordate origins are also welcome. Abstract submission details are at http://apps.mni.mcgill.ca/tunicate/. 

   Ken Hastings on behalf of the Program Committee Chris Cameron, Mary Carman, Jeff Davidson, Robert Lauzon, Alex McDougal, Tom Meedel, Ian Meinertzhagen, Yutaka Satou.

 

3. 7th Intl. Conference on Marine Bioinvasions will be held at the CosmoCaixa Science Museum, Barcelona, Spain, 23-25 August 2011.

Entitled Advances and Gaps in Understanding Marine Bioinvasions, the conference will encompass the following themes: 

Development and Tests of Invasion Theory; Drivers of Invasibility; Patterns of invasion and spread at local, regional, and global scales; Impact of bioinvasions on ecosystem structure and function, including the biology and ecology of invasive species; New tools for identification, monitoring, risk assessment, and management

      We encourage you to submit proposals for special sessions related to these themes to Jeb Byers (jebyers@uga.edu); the deadline for submission is 06 December 2010. [The Ascidian News editors apologize for the lateness of this newsletter but if you have a proposal, please submit anyway.] Sessions may be a half or a full day long; please include a title and list of potential speakers. Dr. Gemma Quilez-Badia  gquilez@atw-wwf.org

 

4. Very interesting recent news release from EastBayRI.com on Univ. of Rhode Island research showing effects of Didemnum vexillum on infaunal diversity and winter flounder nutrition on the Georges Bank, off New England, USA  http://www.eastbayri.com/detail/140050.html  Are Sea Squirts Flounder-Friendly?

 

5. From Noa Shenkar, Arjan Gittenberger, Gretchen Lambert, Marc Rius, Rosana Moreira da Rocha, and Billie J Swalla

         NEW World Ascidiacea Database.

   The World Ascidiacea Database has just gone online as a part of the World Register of Marine Species initiative. It contains all currently accepted scientific names for ascidians and is progressively extended to include all published combinations, allowing both specialists and non-specialists to find the currently accepted name of a certain species.

   Some taxonomic groups are complemented with available literature and pictures.

Link: http://www.marinespecies.org/ascidiacea

 

6. From Mary Carman, Biology Dept., Woods Hole Oceanographic Institution, Woods Hole, MA mcarman@whoi.edu

   The papers from the International Invasive Sea Squirt Conference III (held at Woods Hole MA April 2010) will be published in an upcoming issue of Aquatic Invasions. Guest editors Andrea Locke and Mark Hanson have been receiving manuscripts of work presented at the conference and are in the process of putting together another important collection of research papers. 

   A new session, Invasive Tunicate Ecology, has been added to the next scheduled International Tunicate Meeting. Jeff Davidson, University of Prince Edward Island, and Mary Carman will serve as co-chairs for the session.  Please see Ken Hastings’ 6th ITM announcement above and call for abstracts for the meeting to be held at McGill University in July 2011. 

 

7. My name is Gil Koplovitz and I will be finishing my PhD dissertation at the University of Alabama at Birmingham about chemical defenses in Antarctic and subtropical ascidians around July 2011. I am currently looking for post-doc opportunities with a suitable laboratory. My research interests include chemical ecology, taxonomy and biology of ascidians, polar ecology, marine biological invasions and molecular ecology. My CV can be found at https://sites.google.com/site/gilkop/ and my email is gilkop@uab.edu . Tel. 205-934-8322

 

WORK IN PROGRESS

 

1. Dermatan sulfate in urochordate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Ssulfate) β -1→] motifs in dermatan sulfate on heparin cofactor II activity.

Eliene O. K. Farias1, Paula Lima1, Cristina P. Vicente2, Xingfeng Bao3, Kazuyuki Sugahara4 and Mauro S. G. Pavăo1,2 mpavao@hucff.ufrj.br

1Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho and Programa de Glicobiologia, Instituto de Bioquímica Médica, Univ. Fed. do Rio de Janeiro, Rio de Janeiro, RJ 21941-913, Brasil.  2Instituto de Biologia, Universidade Estadual de Campinas, Săo Paulo, Brasil.  3Glycobiology Unit, Tumor Microenvironment Program, Cancer Research Center, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.  4Graduate Sch. of Life Sci., Hokkaido Univ., Sapporo 001-0021, Japan.

   The present study aimed to investigate the structure of dermatan sulfate (DS) and its ability to potentiate heparin cofactor II during urochordate evolution. To approach that we compared the disaccharide composition of DS polymers obtained from ascidian species of the Orders, Stolidobranchia (considered more primitive) - Herdmania momus, Halocynthia roretzi, Halocynthia pyriformis and Styela plicata and Phlebobranchia (considered more evolved) - Phallusia nigra and Ciona intestinalis. The disaccharide analysis indicated high content of disulfated disaccharide units in the DSs from both Orders. Interestingly, the degree of DS sulfation decreased from the more primitive to the more evolved ascidians. Thus, 76%

of the disaccharide unities in the DSs from primitive stolidobranchia ascidians were disulfated, compared to 53% in the DSs from more evolved phlebobranchia ascidians. The sulfation pattern of the Urochordate DS disaccharides showed interesting results, pointing to an evident structural difference: DSs from evolved Phlebobranchia ascidians contain mainly 2,6-sulfated disaccharides, such as echinoderms and vertebrate. However, DSs from the more primitive stolidobranchia ascidians contain mostly 2,4-sulfated disaccharides. Examining the phylogenetic relations among them, we can observe an alteration from 2,4 disaccharide units [ΔUA(2S)-GalNAc(4S)] in Echinoderms to 2,6 disaccharide units [ΔUA(2S)-GalNAc(6S)] in Phlebobranchia, during Urochordate evolution. Furthermore, in ascidians evolution, we observed an event of evolutionary regression to a 2,4-sulfated DS in Stolidobranchia. Ascidians

DS with a high 2,4-sulfated disaccharide content showed high anticoagulant activity (H. momus and H. roretzi). Assays with C. intestinalis, a 2,6-rich DS, showed low anticoagulant activity. The analysis of the DS structure and anticoagulant activity through HCII indicates a clear correlation between the anticoagulant activity of DS and the presence of 2,4-sulfated units.

 

2. From Patrick Lemaire: Summary of the conclusions of the 1st International Workshop on Tunicate information systems, Nice, France, November 11-14, 2010

  50 people, mainly PIs from Japan, Europe and the USA gathered to plan the future of databases in the tunicate fields. Model species represented included: solitary ascidians (Ciona intestinalis and C. savignyi, Halocynthia roretzi, Phallusia mammillata, Molgula occulta and oculata), colonial ascidians (Botryllus schlosseri, Botrylloides leachi) and larvaceans (Oikopleura dioica). The meeting, sponsored by AVIESAN (France, http://www.aviesan.fr/en) and the DOPAMINET FP7 EU network (http://www.dopaminet.eu/) had two aims: 1) Take census of the current and foreseeable needs of the community, 2) Organize the integration of the current systems to satisfy best the needs of the community.

The meeting was highly successful and led to a 3 yr plan with the aims of fusing together existing databases while a new, more comprehensive system is developed, which will include multiple data sets (genomic, anatomy, embryonic models), and cover solitary and colonial ascidians, as well as larvaceans/thaliaceans, and offer more powerful search interfaces.

   The meeting website can be found at http://www.tunicate-portal.org/TunicateDBMeeting_website/. This site hosts a participant list, slides of most talks, and a summary of the main conclusions of the meeting.    patrick.lemaire@CRBM.CNRS.FR , on behalf of all co-organizers (T. Endo, K. Hotta, K. Inaba, Y. Satou, T. De Tomaso) and Delphine DAUGA, Aniseed Curator Delphine.DAUGA@ibdml.univmed.fr

3. Correlating abiotic factors and genetic patterns in marine invasive species: Importance for their distribution and spread. Mari Carmen Pinedaa, Victor Ordońezb, Christopher McQuaidc, Susanna López-Legentila, Xavier Turond, Marc Riuse

a Dept. de Biologia Animal, Facultat de Biologia, Univ. de Barcelona (mcpineda@ub.edu)   b Dept. de Genčtica, Facultat de Biologia, Univ. de Barcelona

c Department of Zoology and Entomology, Rhodes Univ.   d Centre d’Estudis Avançats de Blanes, CSIC   e Centre for Invasion Biology, Zoology Dept., Univ. of Cape Town

   Since September 2010, I have been working at the Department of Zoology and Entomology, Rhodes University (Grahamstown, South Africa), where I am studying the relationship between physical factors (temperature, salinity and pollutant concentrations) and genetic structure of globally distributed invasive ascidian species. The introduced solitary ascidians Styela plicata and Microcosmus squamiger are good model species because they are globally distributed, their phylogeography is now well understood, they can inhabit polluted waters although their ontogenic stages are likely to be sensitive to pollution stress. Nevertheless, these species differ ecologically within the study area: S. plicata is not present at some localities where M. squamiger can be easily found, suggesting a different tolerance to some abiotic factors. S. plicata usually inhabits polluted environments (harbours and marinas), while M. squamiger can also be found in more undisturbed habitats. In addition, previous genetic studies using the mitochondrial marker COI found important differences between these two species: S. plicata has different genetic composition when comparing two populations (Port Elizabeth and Knysna) along the south coast of South Africa, while the phylogeography of M. squamiger shows no significant genetic differentiation between these two populations.

   Individuals of S. plicata and M. squamiger have been collected from Port Elizabeth and Knysna and we have studied them using a variety of methods: 1) Adults were exposed to different conditions (temperature, salinity and environmentally realistic copper concentrations) and their stress protein (Hsp70) levels were analyzed using western blots; 2) In vitro fertilization was achieved and the effect of the same factors on gametes, fertilization, larvae survival, settlement and metamorphosis was assessed; 3) Sequences of the COI gene of each individual were obtained to correlate the different responses with genetic patterns. This work will be completed in the next few months and will provide important information on the role of stress tolerance for the distribution and spread of these widespread introduced species.

 

4. Does ascidian MIS activate a proteinase activated receptor?

Charles Lambert, Univ. of Washington Friday Harbor Labs, Friday Harbor WA  clambert@fullerton.edu

   At the end of oogenesis many large oocytes with large germinal vesicles (diploid nucleus) are ovulated to be stored in the ovary until spawning. In most ascidian species transfer of ovarian oocytes to sea water results in the onset of meiosis (germinal vesicle breakdown; GVBD). In most other deuterostomes the maturation inducing substance (MIS) is a product of the follicle cells that induces GVBD in the oocytes. In 1991 Sakairi and Shirai proposed that the ascidian MIS was a trypsin-like protease.  Removal of the follicle cells or treatment with soy bean trypsin inhibitor or other protease inhibitors blocked GVBD.  These findings were verified in Lambert 2005, 2008. In the latter paper I also showed that isolated follicle cells released trypsin activity in response to an increase in pH. Current studies indicate that the ovarian pH of Boltenia villosa is below pH 6.

   By the early new century scientists recognized that under certain circumstances proteases could activate receptors by proteolytic cleavage (Steinhoff et al 2005). In some ways this is similar to classical ligand–receptor activation except that it was irreversible. These receptors were termed proteinase activated receptors (PARs). Currently 4 types of PARs are known, PARs 1,3 and 4 which are activated by thrombin  and PAR 2 which requires trypsin and not thrombin for activation (Steinhoff et al 2005). The original 1991 paper of Sakairi and Shirai contains several experiments demonstrating irreversible kinetics and this past summer I carried out additional experiments with Boltenia villosa oocytes showing that activation by trypsin is irreversible and cannot be activated by thrombin. My current hypothesis is that MIS release is inhibited by the acidity of the ovary. Trypsin is released from the follicle cells when the oocytes reach SW (pH 8.2) which binds to and activates an oocyte surface PAR 2 receptor. This irreversibly causes GVBD without the possibility of dilution of the ligand from the transfer from the ovary to SW.

Lambert , C.C. 2005. Signaling pathways in ascidian oocyte maturation: Effects of various inhibitors and activators on germinal vesicle breakdown. Dev. Growth & Differ. 47: 265–272.

Lambert , C.C. 2008. Signaling pathways in ascidian oocyte maturation: The role of cyclic AMP and follicle cells in germinal vesicle breakdown. Dev. Growth & Differ. 50: 181–188.

Sakairi, K. and H. Shirai 1991. Possible MS production by follicle cells in spontaneous oocyte maturation of the ascidian, Halocynthia roretzi. Dev. Growth & Differ. 33(2): 155-162.

Steinhoff, M. et al. 2005. Proteinase-activated receptors: transducers of proteinase-mediated signaling in inflammation and immune response. Endocrine Reviews 26(1):1–43.

 

ABSTRACTS FROM RECENT MEETINGS

 

1. III Meeting Italian Ascidiologists, Palermo, September 2010

Immunolocalizzazione di un peptide antimicrobico nella tunica di Ciona intestinalis (Tunicata). Di Bella M. A.1, Fedders H.2, Leippe M. 2 , De Leo G. 1   mdibella@unipa.it

1 Dipartimento di Biopatologia e Biotecnologie mediche e forensi. Univ. di Palermo, Palermo, Italy; 2 Dept. of Zoophysiology,. Univ. of Kiel, Kiel, Germany.

   I tunicati, sono cordati considerati per la loro posizione filogenetica, modelli significativi nello studio sulla evoluzione del sistema immunitario. Essi mancano di immunitŕ adattativa, ma sono provvisti di un efficient sistema di risposta innata affidata sia a fattori umorali che cellulari.. Di recente č stata identificata nel data base EST dell’ascidia Ciona intestinalis una nuova famiglia di geni putativi di molecole antimicrobiche che č stato dimostrato, sono sintetizzate e accumulate in alcuni emociti. Il peptide sintetico (Ci-MAM-A) esercita

una potente attivitŕ antimicrobica sia nei riguardi dei batteri che contro Candida albicans. Considerato che nei Tunicati, il peculiare tessuto di rivestimento, la tunica, svolge diverse funzioni quail riparazione ferite, attivitŕ immunologiche ed escretorie, riconoscimento del non-self, abbiamo testato anticorpi specifici generati dal peptide sintetico Ci-MAM-A come antigene, sulla tunica di C. intestinalis sia in condizioni fisiologiche, che in condizioni di infiammazione indotta. La molecola naturale č stata localizzata all’interno di alcuni granulociti della tunica e anche nella matrice di essa. Questi dati confermano che interazioni complesse si stabiliscono tra la espressione di molecole antimicrobiche naturali e il coinvolgimento delle cellule durante le reazioni di difesa effettuate contro i microrganismi.

 

2. XVI Simposio Ibérico de Estudios de Biología Marina, Alicante, Spain, 6-10 September 2010.

a)  Ascidian-Cyanobacteria Symbiosis.  Susanna López-Legentila, Bongkeun Songb, Joseph R. Pawlikb, Xavier Turonc

aDept. of Animal Biology (Invertebrates), Univ. of Barcelona. 645 Diagonal Avenue, 08028 Barcelona, Spain (susanna@univ-perp.fr)

bCenter for Marine Science, University of North Carolina Wilmington. 5600 Marvin K. Moss Lane, Wilmington NC 28409, USA

cCentre d’Estudis Avançats de Blanes (CEAB, CSIC), c/ Accés cala St Francesc, 14 17300 Blanes-Girona, Spain

    Symbiotic interactions between ascidians and microbes are only beginning to be explored, with few studies employing the molecular approaches required to accurately assess marine bacterial biodiversity. The majority of ascidian-microbe studies have focused on species within the family Didemnidae that establish symbiotic relationships with unicellular cyanobacteria from the genera Prochloron (Prochlorales) and Synechocystis (Chroococcales). These photosynthetic symbionts provide the host ascidians with a green or red pigmentation and an array of secondary metabolites, some of which have promising pharmaceutical properties. We have reviewed the existent literature on ascidian-cyanobacteria symbiosis and added our own research to the field by characterizing the cyanobacterial population of the didemnind species Trididemnum solidum, Trididemnum aff. cyanophorum,  and Lissoclinum fragile. We sequenced first a fragment of the16S rRNA of 771 bp, and then extended these sequences to 1491 bp by including the entire 16S-23S rRNA internal transcribed spacer (ITS). Blast searches in GenBank showed that the best match for the main symbiont of Trididemnum solidum and Trididemnum aff. cyanophorum was Prochloron didemni (98% identity, 97% coverage; and 98% identity, 94% coverage respectively). For Lissoclinum fragile Blast searches with the 16S rRNA fragment of its main symbiont showed that the closer match was the freshwater cyanobacteria Leptolyngbya badia (95% max. identity, 100% coverage); while Blast searches using the full length of our sequences returned both Acaryochloris marina (95% identity; 85% coverage) and Leptolyngbya badia (100% identity, 61% coverage) as best matches. Unlike Prochloron, which was originally described as an ascidian symbiont, there is no record of ascidian symbiosis with Leptolyngbia. More intriguing will be a symbiosis with a cyanobacteria closely related to A. marina. A. marina is known to be the only oxygenic photoautotroph that uses chl d as the predominant photosynthetic pigment, and has been found growing on biofilms beneath didemnid ascidians, and more recently at the base of the ascidian Cystodytes dellechiajei (Policytoridae). Electron transmission microscope (TEM) observations revealed the presence in the tunic and the larvae of L. fragilum of cyanobacteria similar in structure and size to A. marina, suggesting that the symbionts were vertically transmitted to the progeny and reinforcing the symbiotic character of this group. Finally, we point out that, as found for sponges, ITS gene sequences displayed much higher variability than 16S rRNA sequences, highlighting the utility of ITS sequences in determining the genetic diversity and host specificity of symbiont populations among ascidian species.

 

b) Introductions and expansions: genetic differentiation and phylogeographic patterns in the solitary ascidian Styela plicata. Mari Carmen Pineda a, Susanna López-Legentila, Xavier Turonb

aDept. de Biologia Animal, Facultat de Biologia, Univ. de Barcelona (mcpineda@ub.edu)

bCentre d’Estudis Avançats de Blanes, CSIC

   Marine introductions have increased considerably during the last century and are threatening native biodiversity while interfering with shellfish aquaculture and other fishery activities. Styela plicata (Lesueur, 1823) is a solitary ascidian widely distributed in both tropical and temperate waters, although its origin remains unclear. The aim of this study was to infer the genetic structure and phylogeography of S. plicata on a worldwide scale and to assess the potential role of ship transport on the current distribution of this species. To address this question we have analyzed two genetic markers: a fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) and a fragment spanning the intron of the nuclear gene Adenine Nucleotide Transporter/ADP-ATP Translocase (ANT). A total of 344 individuals for COI and 291 for ANT were obtained from 2 locations on the Mediterranean Sea, 6 from the Atlantic, 6 from the Pacific and 2 from the Indian Ocean. The nuclear marker had a higher gene diversity (mean 0.764) and nucleotide diversity (mean 0.029) than the mitochondrial marker (0.487 and 0.005, respectively). The Mediterranean populations showed the least diversity for both markers, while the Indian Ocean and Western Atlantic (ANT) and Western Atlantic (COI) had the highest diversity in terms of both haplotypes and nucleotides. For COI we found two well-supported groups of haplotypes (>3% of divergence) but no clear phylogenetic structure was retrieved with ANT. Genetic divergence was significant for many population-pairs, especially for COI, irrespective of the geographic distance among them (i.e., no evidence of isolation by distance). Our results suggest that S.plicata has been present in all the studied oceans for a long time, possibly through recurrent introduction events via maritime transport. The source of the species’ expansion could not be unambiguously identified, although overall the Western Atlantic populations were the most diverse. The Mediterranean Sea seems to have been colonized more recently, judging from the low diversity and number of private haplotypes (only one for each marker). Stochasticity of the introduction events is reflected in the uneven distribution of both COI haplotype groups, the significant differences in haplotype frequencies among many populations, and the fact that there are populations with an excess or deficit of homozygotes for ANT. Although this species has been mainly found in harbour and artificial platforms, the potential spread of its populations to natural substrates cannot be discounted. Further studies regarding the invasive potential of S.plicata on a smaller geographic scale are necessary, together with an in-depth characterization of its reproductive cycles, recruitment rates and growth patterns.

 

c) Reproductive cycle of the invasive ascidian Styela plicata in the NW Mediterranean Sea. Mari Carmen Pinedaa, Alba Muntadasa, Roger Esplugaa, Susanna López-Legentila, Xavier Turonb

aDept. de Biologia Animal, Facultat de Biologia, Univ. de Barcelona (mcpineda@ub.edu)

bCentre d’Estudis Avançats de Blanes (CEAB, CSIC)

   The solitary ascidian Styela plicata (Lesuer, 1823) presents nowadays a wide distribution in both tropical and temperate waters, being some of the main components of the fouling communities in most harbours and marinas all around the world. The geographical origin of this species is uncertain but at present it can be certainly considered as introduced in most of its distributional range. Although this species has the ability to modify natural communities and hence produce important economical impacts, studies about the biological cycle of this species are scarce. Our aim was to study the reproductive cycle of Styela plicata in the NW Mediterranean and for that purpose on January 2009 we started collecting monthly samples of this species at two localities within the Catalan coast. These localities were situated in the interior of the harbours of Vilanova i la Geltrú and Blanes, both separated by 100 Km, and representing two different kinds of harbour, being the former bigger and more polluted than the latter.

   Once in the laboratory, the animals were measured (length, width and height) and after removing the tunic and opening the mantle, the gonads were dissected. Wet and dry weights of gonads and mantle were used to calculate a gonadosomatic index (GSI). Moreover, one of the gonads on the right side of the animal was used to assess the maturity state through histological sections. Simultaneously, temperature and salinity of the water at both localities was registered, as well as recruitment observed, growth and population structure in the Vilanova i la Geltrú population. The GSI results showed similar patterns for both populations, with a minimum in April that corresponded to the shedding of gametes and, hence, the main reproductive event. This reproductive event was followed by a gradual increment of the gonads during the subsequent months, reaching the maximum values in August. The temporal evolution of the GSI also indicated the existence of minor reproductive events in autumn, although in that case they do not seem simultaneous for both populations studied.  Gonad histology and oocyte size-frequency analyses confirmed a main spawning episode and the presence of mature oocytes and sperm during most of the year. Moreover, the presence of recruits has been observed all year long, suggesting that a partial gamete release can be taking place outside the main reproductive events.  We conclude that S. plicata presents a long reproductive cycle within the studied area, which could facilitate the colonization of new substrata and therefore competition with other species.

 

3. 81st Annual Meeting of the Zoological Society of Japan, Tokyo, Japan, 21-23 September 2010.

Organization of the neural complex of Symplegma sp. (viride?). Hiromichi Koyama, College of Nursing, Sch. of Medicine, Yokohama City Univ.

hkoyama@med.yokohama-cu.ac.jp

  I examined the structure of the neural complex of Symplegma sp. by light microscopic sections of Technovit 7100.  The ciliated funnel has a simple slit-like structure.  The cytoplasm of the funnel cells with inward long cilia stains faintly with cresyl violet. This tendency has been seen in all species studied so far.  The cerebral ganglion is ovoid, and has a maximum diameter of 90 μm and a maximum length of 120 μm.  The cerebral ganglion consists of cellular cortex and fibrous medulla.  Most of the somata of the neurons are small (about 5 μm in diameter), but several huge somata (more than 10 μm in diameter) are observed.  The neural gland is small and located above the anterior part of the cerebral ganglion. The neural gland consists of the cells with a large vacuole. The dorsal strand does not form a dorsal organ like Botryllus schlosseri, which belongs to the same subfamily as Symplegma.  The dorsal strand descends a little behind the cerebral ganglion, and expands.  The dorsal strand cells are connected loosely near the caudal end of it, and some cells become free.  This situation is similar to the terminal cells of the dorsal strand of Polyandrocarpa misakiensis, a colonial styelid ascidian.  Just as the terminal cells of P. misakiensis, the terminal cells of Symplegma sp. have a large inclusion stained red with cresyl violet. (Prof. T. Nishikawa is identifying the material of this study right now.)

 

4. 7th Intl. Symposium on the Chemistry and Biological Chemistry of Vanadium, October 6-9, 2010, Toyama City, Japan (http://www.vanadiumseven.com/).

    The symposium was chaired by Prof. Hitoshi Michibata, Hiroshima University, and two co-chairs, Prof. Kan Kanamori, University of Toyama, and Prof. Toshikazu Hirao, Osaka University. A special issue in Coordination Chemistry Reviews will be released in early 2011.

   The following presentations were presented from Prof. Michibata's laboratory, Dept. of Biological Sci., Graduate School of Science, Hiroshima Univ., 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan. hmichi@hiroshima-u.ac.jp  Asterisks indicate presenting author.

a) Molecular mechanism of the transport and reduction pathway of vanadium in ascidians.

*Tatsuya Ueki and Hitoshi Michibata. ueki@hiroshima-u.ac.jp  

 

b) poster: Identification of genes regulated by excess vanadium ions in ascidians, focusing on redox and accumulation of metals. *Satoshi Kume, Tatsuya Ueki and Hitoshi Michibata. Dept. of Biological Sci., Graduate School of Science, Hiroshima Univ.  The gold prize of Outstanding Poster Awards for Young Scientists was given to Mr. Satoshi Kume for this poster.

 

c) poster: Expressed sequence tag (EST) analysis of the intestine from the most vanadium-rich ascidian Ascidia gemmata,  and  their application to heavy metal biosorption system. *Setijono Samino, Tatsuya Ueki, and Hitoshi Michibata

 

d) poster: Measurement and comparison of V(V)-reductase activity of Vanabin family of a vanadium-rich ascidian Ascidia sydneiensis samea. *Tomoya Kimizu, Tatsuya Ueki and Hitoshi Michibata.

 

5. 5th National Conference and Expo on Coastal and Estuarine Habitat Restoration, Galveston, Texas, November 13-17, 2010

 

The impact of invasive tunicates in marine coastal eelgrass habitats in Massachusetts

Grunden, David W.1; Carman, M.R.2; Colarusso, P.3; Chintala, M.M.4; Blackwood, D.S.5

1Oak Bluffs Shellfish Dept., P. O. Box 1327, Oak Bluffs, MA 02557

2Biology Dept., Woods Hole Oceanographic Institution, Woods Hole, MA 02543

3US Environmental Protection Agency, 5 Post Office Square, Suite 100, Boston, MA 02109

4US Environmental Protection Agency, Atlantic Ecology Division, 27 Tarzwell Dr, Narragansett, RI 02882

5US Geological Survey, 360 Woods Hole Rd, Woods Hole, MA 02543

     Non-native tunicates have been invading New England marine coastal environments during the past 30 years, and are now posing a potential threat to eelgrass.  Tunicates (Ascidiacea) are invertebrate marine filter feeders that overgrow natural and artificial substrates.  Eelgrass (Zostera marina) beds are cosmopolitan, productive, and high diversity habitats that provide many significant ecosystem services (e.g., support a trophic food web, stabilize sediments, serve as nursery grounds for commercially important fish and shellfish).  The consequences of invasive tunicates in coastal habitats can be devastating.  For example, Didemnum vexillum has caused economic loss for New England sea scallop fishermen offshore at Georges Bank and shellfish aquaculturists in near shore waters and caused ecological destruction in intertidal and subtidal benthic communities.  In 2008 and 2009, after decades of monitoring eelgrass meadows in Massachusetts, we found Botrylloides violaceus on eelgrass throughout Major’s Cove in Sengekontacket Pond, B. violaceus, D. vexillum, and Diplosoma listerianum attached to eelgrass in the middle area of Lake Tashmoo, and Ascidiella aspersa, B. violaceus, and D. vexillum on eelgrass throughout Stonewall Pond on Martha’s Vineyard; D. listerianum on eelgrass in patches at the east entrance to the Cape Cod Canal; and B. violaceus and D. listerianum on eelgrass at Gloucester Harbor and Cape Ann in northern Massachusetts.  In Massachusetts, the exotic tunicates A. aspersa and D. vexillum have adapted to utilizing eelgrass as substrate and B. violaceus and D. listerianum, previously known to use eelgrass as substrate elsewhere, have vigorously spread into eelgrass habitats.  This is the first recorded occurrence of A. aspersa and D. vexillum to use eelgrass as substrate.  However, it is unknown if these are isolated incidents or indicative of a future trend.  Tunicates commonly occurred as small patches on outer eelgrass blades but in some cases, D. vexillum encapsulated the plants to such an extent that they could no longer naturally defoliate or release seed.  Tunicates likely block sunlight from reaching the blade, inhibiting necessary photosynthesis.  Tunicate growth on eelgrass blades where epiphytic algae would otherwise be present appears to inhibit herbivorous grazers.  Invasive tunicates are probably negatively impacting eelgrass, however, their filtration capacity may have a positive impact on the ecosystem by consuming excess phytoplankton and bacteria from the water.  Changes in the environment such as warming water temperatures, ocean acidification, and excess nutrients may contribute to the success of these invaders.  Climate change has negatively impacted native tunicates thus enabling non-native tunicates that have a greater temperature tolerance.  Warming sea temperatures are shifting species’ ranges due to species’ thermal tolerances.  Continued monitoring of eelgrass is necessary to determine the full impact of invasive tunicates on eelgrass beds.

 

6. Proc. of Natl. seminar on Biodiversity Conservation & Management of Aquatic Resources (NSBCMA 2010), 9-10 December 2010

A survey on invasive ascidians in south coast of India

Jaffar Ali H A, Sivakumar V and Tamilselvi M, Directorate of Research and Extension (Fisheries), Tamilnadu Veterinary & Animal Sciences Univ., Thoothukudi, India.

   Invasive ascidians are a dominant feature of many sessile marine fouling communities throughout the world and may have negative effects on species diversity. There are 12 major ports and numerous minor ports along the 7,500km long Indian coastline, which may act as gateways for marine bio-invasions. The distribution and impact of invasive ascidians in India are less well documented but unsparing problems are developing and hence the present study was aimed to document the invasive ascidians in the South Indian coastal waters.  In this paper both literature data and results from the field surveys conducted at ten coastal areas of south India during 2008-2010 were utilized to compile a checklist of invasive ascidians along the southern coasts of India. A total of sixty one species of ascidians has been reported in the present study. Among these, fifty four ascidians have been believed to be invasive species, with mostly from Australian origin. Seven ascidians are found as established invasive. Their arrival has been mainly due to shipping and ballast waters and some that have arrived recently may have significant future impact. The discovery of several new records during the survey indicates that the rate of introductions has substantially increased over the last two decades. The impact of the established invasive ascidians on sessile invertebrate community in Tuticorin and Vizhinjam Bay has already noted and a prediction has also been made on bioinvasion.

 

NEW PUBLICATIONS

 

Ben-Shlomo, R., Reem, E., Douek, J. and Rinkevich, B. 2010. Population genetics of the invasive ascidian Botryllus schlosseri from South American coasts. Marine Ecology Progress Series 412: 85–92.

Bonura, A., Vizzini, A., Salerno, G., Parrinello, D., Parrinello, N., Longo, V., Montana, G. and Colombo, P. 2010. Cloning and expression of a novel component of the CAP superfamily enhanced in the inflammatory response to LPS of the ascidian Ciona intestinalis. Cell and Tissue Research 342: 411-421.

Bremec, C. and Schejter, L. 2010. Benthic diversity in a submarine canyon in the Argentine sea. Revista Chilena de Historia Natural 83: 453-457.

Brunetti, R. 2010. Redescription of Botrylloides magnicoecum (Hartmeyer, 1912) based on the analysis of the type (Tunicata, Styelidae, Botryllinae). Boll. Mus. civ. St. Nat. Venezia 61: 45-58.

Bullard, S. G., Shumway, S. E. and Davis, C. V. 2010. The use of aeration as a simple and environmentally sound means to prevent biofouling. Biofouling 26: 587–593.

Burighel, P., Caicci, F. and Manni, L. 2010. Hair cells in non-vertebrate models: lower chordates and molluscs. Hearing Research in press.

Caicci, F., Degasperi, V., Gasparini, F., Zaniolo, G., Del Favero, M., Burighel, P. and Manni, L. 2010. Variability of hair cells in the coronal organ of ascidians (Chordata, Tunicata). Canadian Journal of Zoology 88: 567-578.

Carman, M. R., Morris, J. A., Karney, R. C. and Grunden, D. W. 2010. An initial assessment of native and invasive tunicates in shellfish aquaculture of the North American east coast. Journal of Applied Ichthyology 26: 8–11.

Carroll, A. R., Duffy, S. and Avery, V. M. 2010. Aplidiopsamine A, an antiplasmodial alkaloid from the temperate Australian ascidian, Aplidiopsis confluata. Journal of Organic Chemistry 75: 8291-8294.

Chebbi, N., Mastrototaro, F. and Missaoui, H. 2010. Spatial distribution of ascidians in two Tunisian lagoons of the Mediterranean Sea. Cahiers de Biologie Marine 51: 117-127.

Choi, H., Hwang, H., Chin, J., Kim, E., Lee, J., Nam, S. J., Lee, B. C., Rho, B. J. and Kang, H. 2010. Tuberatolides, Potent FXR antagonists from the Korean marine tunicate Botryllus tuberatus. Journal of Natural Products epub.

Collin, S. B., Oakley, J. A., Sewell, J. and Bishop, J. D. D. 2010. Widespread occurrence of the non-indigenous ascidian Corella eumyota Traustedt, 1882 on the shores of Plymouth Sound and Estuaries Special Area of Conservation, UK. Aquatic Invasions 5: 175-179.

Cooper, E. L. 2009. Putative stem cell origins in solitary tunicates. In: Stem Cells in Marine Organisms. Rinkevich, B. and Matranga, V. eds. Springer Netherlands, pp. 21-32.

Cooper, E. L. 2010. Evolution of immune systems from self/not self to danger to artificial immune systems (AIS). Physics of Life Reviews 7: 55–78.

David, G. K., Marshall, D. J. and Riginos, C. 2010. Latitudinal variability in spatial genetic structure in the invasive ascidian, Styela plicata. Marine Biology `57: 1955-1965.

Davis, M. H. and Davis, M. E. 2010. The impact of the ascidian Styela clava Herdman on shellfish farming in the Bassin de Thau, France. Journal of Applied Ichthyology 26: 12-18.

Demarchi, M., Chiappero, M., Tatián, M. and Sahade, R. 2010. Population genetic structure of the Antarctic ascidian Aplidium falklandicum from Scotia Arc and South Shetland Islands. Polar Biology 33 (11): 1567-1576.

Denoeud, F., Henriet, S., Mungpakdee, S. and al., e. 2010. Plasticity of animal genome architecture unmasked by rapid evolution of a pelagic tunicate. Science 330: 1381-1385.

Dupont, L., Viard, F., Davis, M. H., Nishikawa, T. and Bishop, J. D. D. 2010. Pathways of spread of the introduced ascidian Styela clava (Tunicata) in Northern Europe, as revealed by microsatellite markers. Biological Invasions 12: 2707-2721.

Edwards, K. F. and Stachowicz, J. J. 2010. Multivariate trade-offs, succession, and phenological differentiation in a guild of colonial invertebrates. Ecology 91: 3146–3152.

Endo, T., Ueno, K., Yonezawa, K., Mineta, K., Hotta, K., Satou, Y. (and 14 additional authors) 2010. CIPRO 2.5: Ciona intestinalis protein database, a unique integrated repository of large-scale genomics data, bioinformatic analyses and curated annotation, with user rating and reviewing functionality. Nucleic Acids Research epub.

Franchi, N., Boldrin, F., Ballarin, L. and Piccinni, E. 2010. CiMT-1, an unusual chordate metallothionein gene in Ciona intestinalis genome: structure and expression studies. Journal of Experimental Zoology A 313A:

Franchi, N., Schiavon, F., Carletto, M., Gasparini, F., Bertoloni, G., Tosatto, S. C. and Ballarin, L. 2010. Immune roles of a rhamnose-binding lectin in the colonial ascidian Botryllus schlosseri. Immunobiology epub.

Geller, J. B., Darling, J. A. and Carlton, J. T. 2010. Genetic perspectives on marine biological invasions. Annual Review of Marine Science 2: 367-393.

Gittenberger, A., Rensing, M., Stegenga, H. and Hoeksema, B. 2010. Native and non-native species of hard substrata in the Dutch Wadden Sea. Nederlandse Faunistische Mededelingen 33: 21-75.

Grey, E. K. 2010. Effects of large enemies on success of exotic species in marine fouling communities of Washington, USA. Marine Ecology Progress Series 411: 89-100.

Hamida, N. B. H., Hamida-Ben A., O. B. H., Ghorbel, M., Jarboui, O. and Missaoui, H. 2010. The feeding habits of the bluespotted seabream, Pagrus caeruleostictus (Valenciennes, 1830), in the Gulf of Gabes (Central Mediterranean). Reviews in Fisheries Science 18: 65-72.

Haydar, D. 2010. What is natural? The scale and consequences of marine bioinvasions in the North Atlantic Ocean. Van Denderen BV, Groningen, The Netherlands. 184 pp.

Hirose, E. and Nozawa, Y. 2010. Photosymbiotic ascidians from Kenting and Lyudao in Taiwan. Zoological Studies 49: 681-687.

Hirose, M., Tochikubo, T. and Hirose, E. 2010. Taxonomic significance of tunic spicules in photosymbiotic ascidians: a quantitative and molecular evaluation. Journal of the Marine Biological Association U. K. 90: 1065–1071.

Hirose, M., Nozawa, Y. and Hirose, E. 2010. Genetic isolation among morphotypes in the photosymbiotic didemnid Didemnum molle (Ascidiacea, Tunicata) from the Ryukyus and Taiwan. Zoological Science 27: 959–964.

Holland, L. Z. and Sower, S. A. 2010. "Insights of Early Chordate Genomics: Endocrinology and Development in Amphioxus, Tunicates and Lampreys": Introduction to the symposium. Integrative and Comparative Biology 50: 17-21.

Jaffar Ali, H. A., Sivakumar, V. and Tamilselvi, M. 2009. Distribution of alien and cryptogenic ascidians along the southern coasts of Indian Peninsula. World Journal of Fish and Marine Sciences 1: 305-312.

Jaffar Ali, H. A., Sivakumar, V. and Tamilselvi, M. 2010. New record of colonial ascidians from south west coast off India. Middle-East Journal of Scientific Research 5: 366 -373.

Jiang, L., Liu, Q. and Ni, J. 2010. In silico identification of the sea squirt selenoproteome. BMC Genomics 11: 289.

Kano, S. 2010. Genomics and developmental approaches to an ascidian adenohypophysis primordium. Integrative and Comparative Biology 50: 35-52.

Kashin, I. A., Bagaveeva, E. V. and Chaplygina, S. F. 2003. Fouling communities of hydrotechnical constructions in Nakhodka Bay (Sea of Japan). Russian Journal of Marine Biology 29: 267–283.

Kashman, Y., Bishara, A. and Aknin, M. 2010. Recent N-atom containing compounds from indo-pacific invertebrates. Marine Drugs 8: 2810-2836.

Khalaman, V. V. 2010. Life span and growth rate of Styela rustica (Ascidiae, Chordata) inhabiting the White Sea [in Russian; English abstract]. Russian Journal of Zoology 89: 1268-1272.

Khare, P., Mortimer, S. I., Cleto, C. L., Okamura, K., Suzuki, Y., Kusakabe, T., Nakai, K., Meedel, T. H. and Hastings, K. E. 2010. Cross-validated methods for promoter/transcription start site mapping in SL trans-spliced genes, established using the Ciona intestinalis troponin I gene. Nucleic Acids Research epub.

Khoueiry, P., Rothbacher, U., Ohtsuka, Y., Daian, F., Frangulian, E., Roure, A., Dubchak, I. and Lemaire, P. 2010. A cis-regulatory signature in ascidians and flies, independent of transcription factor binding sites. Current Biology 20: 792-802.

Kitano, T., Satou, M. and Saitou, N. 2010. Evolution of two Rh blood group-related genes of the amphioxus species Branchiostoma floridae. Genes & Genetic Systems 85: 121-127.

Kondilatos, G., Corsini-Foka, M. and Pancucci-Papadopoulou, M.-A. 2010. Occurrence of the first non-indigenous ascidian Phallusia nigra Savigny, 1816 (Tunicata: Ascidiacea) in Greek waters. Aquatic Invasions 5: 181-184.

Kugler, J. E., Gazdoiu, S., Oda-Ishii, I., Passamaneck, Y. J., Erives, A. J. and Di Gregorio, A. 2010. Temporal regulation of the muscle gene cascade by Macho1 and Tbx6 transcription factors in Ciona intestinalis. Journal of Cell Science 123: 2453-2463.

Kumagai, A., Suto, A., Ito, H., Tanabe, T., Takahashi, K., Kamaishi, T. and Miwa, S. 2010. Mass mortality of cultured ascidians Halocynthia roretzi associated with softening of the tunic and flagellate-like cells. Diseases of Aquatic Organisms 90: 223-234.

Lagger, C., Häussermann, V., Försterra, G. and Tatián, M. 2009. Ascidians from the southern Chilean Comau Fjord (Chordata, Ascidiacea). Spixiana 32: 173-185.

Lambert, G., Shenkar, N. and Swalla, B. J. 2010. First Pacific record of the north Atlantic ascidian Molgula citrina – bioinvasion or circumpolar distribution? Aquatic Invasions 5 (4): 369-378.

Lescano, N., Fuentes, V. L., Sahade, R. and Tatián, M. 2010. Identification of gut contents and microscopical observations of the gut epithelium of the macrophagous ascidian Cibacapsa gulosa Monniot & Monniot, 1983 (Phlebobranchia, Octacnemidae). Polar Biology epub.

Lipari, L., Gerbino, A., Lipari, D. and Farina, E. V. 2010. ANP (Atrial Natriuretic Peptide) presence in the heart of a tunicate, Ciona intestinalis. Folia Histochemica et Cytobiolica 48: 68-70.

Manriquez, P. H. and Castilla, J. C. 2010. Fertilization efficiency and gamete viability in the ascidian Pyura praeputialis in Chile. Marine Ecology Progress Series 409: 107-119.

Menezes, C. B. A., Bonugli-Santos, R. C., Miqueletto, P. B., Passarini, M. R. Z., Silva, C. H. D., Justo, M. R., Leal, R. R., Fantinatti-Garboggini, F., Oliveira, V. M., Berlinck, R. G. S. and Sette, L. D. 2010. Microbial diversity associated with algae, ascidians and sponges from the north coast of Sao Paulo state, Brazil. Microbiological Research 165: 466-482.

Monniot, F. 2010. Some new data on tropical western Pacific ascidians. Zootaxa 2561: 1–29.

Munguia, P., Osman, R. W., Hamilton, J., Whitlatch, R. B. and Zajac, R. N. 2010. Modeling of priority effects and species dominance in Long Island Sound. Marine Ecology Progress Series 413: 229-240.

Nagar, A. E., Huys, R. and Bishop, J. D. D. 2010. Widespread occurrence of the southern hemisphere ascidian Corella eumyota Traustedt, 1882 on the Atlantic coast of Iberia. Aquatic Invasions 5: 169-173.

Nakashima, K., Nishino, A., Horikawa, Y., Hirose, E., Sugiyama, J. and Satoh, N. 2010. The crystalline phase of cellulose changes under developmental control in a marine chordate. Cell and Molecular Life Science epub:

Nanri, K., Ogawa, J. and Nishikawa, T. 1992. Tunic of pyurid ascidian Microcosmus hartmeyeri Oka is eaten locally in Japan. Nanki Seibutu 34 (2): 135.

Nova-Bustos, N., Hernandez-Zanuy, A. C. and Viquez-Portuguez, R. 2010. Distribution and abundance of the rocky bottom ascidians of Cuajiniquil Bay, Costa Rica. Boletin de Investigaciones Marinas y Costeras 39: 57-66.

Nunez-Pons, L., Forestieri, R., Nieto, R. M., Varela, M., Nappo, M., Rodriguez, J., Jimenez, C., Castelluccio, F., Carbone, M., Ramos-Espla, A., Gavagnin, M. and Avila, C. 2010. Chemical defenses of tunicates of the genus Aplidium from the Weddell Sea (Antarctica). Polar Biology 33: 1319-1329.

Nydam, M. L. and Harrison, R. G. 2010. Introgression despite substantial divergence in a broadcast spawning marine invertebrate. Evolution epub.

Obara, B., Veeman, M., Choi, J. H., Smith, W. and Manjunath, B. S. 2010. Segmentation of ascidian notochord cells in DIC timelapse images. Microscopy Research and Technique epub.

Oda-Ishii, I., Ishii, Y. and Mikawa, T. 2010. Eph regulates dorsoventral asymmetry of the notochord plate and convergent extension-mediated notochord formation. PLoS One 5: e13689.

Ohshiro, K., Obinata, T., Dennisson, J. G., Ogasawara, M. and Sato, N. 2010. Troponin in both smooth and striated muscles of ascidian Ciona intestinalis functions as a Ca(2+)-dependent accelerator of actin-myosin interaction. Biochemistry epub:

Ohta, N., Horie, T., Satoh, N. and Sasakura, Y. 2010. Transposon-mediated enhancer detection reveals the location, morphology and development of the cupular organs, which are putative hydrodynamic sensors, in the ascidian Ciona intestinalis. Zoological Science 27: 842-850.

Okamura, K., Matsumoto, K. A. and Nakai, K. 2010. Gradual transition from mosaic to global DNA methylation patterns during deuterostome evolution. BMC Bioinformatics 11 Suppl 7: S2.

Ooishi, S. 2010. Enterocola hessei Chatton & Harant (Copepoda: Cyclopoida: Ascidicolidae) living in the compound ascidian Clavelina lepadiformis (Müller). Proceedings of the Biological Society of Washington 123: 37–148.

O'Reilly, M. 2008. New records of copepods associated with ascidians from Scottish waters, including the description of a new species Enterocola ooishiae n. sp. (Cyclopoida, Ascidicolidae), from a simple ascidian. The Glasgow Naturalist 25: 57–74.

Orensanz, J. M., Schwindt, E., Pastorino, G., Bortolus, A., Casas, G., Darrigran, G., Elias, R., Gappa, J. J. L., Obenat, S., Pascual, M., Penchaszadel, P., Piriz, M. L., Scarabino, F., Spivak, E. D. and Vallarino, E. A. 2002. No longer the pristine confines of the world ocean: a survey of  exotic marine species in the southwestern Atlantic. Biological Invasions 4: 115–143.

Osman, R. W., Munguia, P., Whitlatch, R. B., Zajac, R. N. and Hamilton, J. 2010. Thresholds and multiple community states in marine fouling communities: integrating natural history with management strategies. Marine Ecology Progress Series 413: 277-289.

Parrinello, N., Vizzini, A., Salerno, G., Sanfratello, M. A., Cammarata, M., Arizza, V., Vazzana, M. and Parrinello, D. 2010. Inflamed adult pharynx tissues and swimming larva of Ciona intestinalis share CiTNF alpha-producing cells. Cell & Tissue Research 341: 299-311.

Parton, R. M. and Davis, I. 2010. How the sea squirt nucleus tells mesoderm not to be endoderm. Development Cell 19: 487-488.

Plotkin, A. S., Railkin, A. I., Gerasimova, E. I., Pimenov, A. Y. and Sipenkova, T. M. 2005. Subtidal underwater rock communities of the White Sea: structure and interaction with bottom flow. Russian Journal of Marine Biology 31: 335–343.

Rabinowitz, C. and Rinkevich, B. 2010. De novo emerged stemness signatures in epithelial monolayers developed from extirpated palleal buds. In Vitro Cell and Developmental Biology—Animal epub.

Raff, R. A. and Love, A. C. 2004. Kowalevsky, comparative evolutionary embryology, and the intellectual lineage of evo-devo. Journal of Experimental Zoology (Mol. Dev. Evol.) 302B: 19-34.

Rajesh, R. P., Ramasamy, M. S. and Murugan, A. 2010. Anticancer activity of the ascidian Polyclinum indicum against cervical cancer cells (HeLa) mediated through apoptosis induction. Medicinal Chemistry epub.

Reinhardt, J. F., Stefaniak, L. M., Hudson, D. M., Mangiafico, J., Gladych, R. and Whitlatch, R. B. 2010. First record of the non-native light bulb tunicate Clavelina lepadiformis (Müller, 1776) in the northwest Atlantic. Aquatic Invasions 5: 185-190.

Rinkevich, Y., Rosner, A., Rabinowitz, C., Lapidot, Z., Moiseeva, E. and Rinkevich, B. 2010. Piwi positive cells that line the vasculature epithelium, underlie whole body regeneration in a basal chordate. Developmental Biology 345: 94–104.

Rius, M., Branch, G. M., Griffiths, C. L. and Turon, X. 2010. Larval settlement behaviour in six gregarious ascidians in relation to adult distribution. Marine Ecology Progress Series 418: 151–163.

Roch, G. J. and Sherwood, N. M. 2010. Genomics reveal ancient forms of stanniocalcin in amphioxus and tunicate. Integrative and Comparative Biology 50: 86-97.

Rocha, R. M., Cangussu, L. C. and Braga, M. P. 2010. Stationary substrates facilitate bioinvasion in Paranagua Bay in southern Brazil. Brazilian Journal of Oceanography 58: 23-28.

Romanenko, L. A., Kalinovskaya, N. I. and Mikhailov, V. V. 2001. Taxonomic composition and biological activity of microorganisms associated with a marine ascidian Halocynthia aurantium. Russian Journal of Marine Biology 27: 291-296.

Saffo, M. B., McCoy, A. M., Rieken, C. and Slamovits, C. H. 2010. Nephromyces, a beneficial apicomplexan symbiont in marine animals. Proceedings of the National Academy of Sciences 107: 16190-16195.

Sanamyan, K., Schories, D. and Sanamyan, N. 2010. New records of aplousobranch ascidians from Central Chile. Zootaxa 2537: 58–68.

Schmidt, E. W. and Donia, M. S. 2010. Life in cellulose houses: symbiotic bacterial biosynthesis of ascidian drugs and drug leads. Current Opinion in Biotechnology 21: 827-833.

Sherrard, K., Robin, F., Lemaire, P. and Munro, E. 2010. Sequential activation of apical and basolateral contractility drives ascidian endoderm invagination. Current Biology 20: 1499-1510.

Silvestre, F., Gallo, A., Cuomo, A., Covino, T. and Tosti, E. 2010. Role of cyclic AMP in the maturation of Ciona intestinalis oocytes. Zygote epub: 1-7.

Sirenko, B. I. 2009. Main differences in macrobenthos and benthic communities of the Arctic and Antarctic, as illustrated by comparison of the Laptev and Weddell Sea faunas. Russian Journal of Marine Biology 35: 445-453.

Smith, K. F., Cahill, P. L. and Fidler, A. E. 2010. First record of the solitary ascidian Ciona savignyi Herdman, 1882 in the Southern Hemisphere. Aquatic Invasions 5 (4): 363-368

Sorte, C. J., Williams, S. L. and Zerebecki, R. A. 2010. Ocean warming increases threat of invasive species in a marine fouling community. Ecology 91: 2198-2204.

Stolfi, A., Gainous, T. B., Young, J. J., Mori, A., Levine, M. and Christiaen, L. 2010. Early chordate origins of the vertebrate second heart field. Science 329: 565-568.

Sugumaran, M. and Robinson, W. E. 2010. Bioactive dehydrotyrosyl and dehydrodopyl compounds of marine origin. Marine Drugs 8: 2906-2935.

Sunanaga, T., Inubushi, H. and Kawamura, K. 2010. Piwi-expressing hemoblasts serve as germline stem cells during postembryonic germ cell specification in colonial ascidian, Botryllus primigenus. Development Growth & Differentiation 52: 603-614.

Sutherland, K. R., Madin, L. P. and Stocker, R. 2010. Filtration of submicrometer particles by pelagic tunicates. Proceedings of the National Academy of Sciences 107: 15129-15134.

Tadesse, M., Strom, M. B., Svenson, J., Jaspars, M., Milne, B. F., Torfoss, V., Andersen, J. H., Hansen, E., Stensvag, K. and Haug, T. 2010. Synoxazolidinones A and B: novel bioactive alkaloids from the ascidian Synoicum pulmonaria. Organic Letters 12: 4752-4755.

Takahashi, Y., Ishiyama, H., Kubota, T. and Kobayashi, J. 2010. Eudistomidin G, a new beta-carboline alkaloid from the Okinawan marine tunicate Eudistoma glaucus and structure revision of eudistomidin B. Bioorganic & Medicinal Chemistry Letters 20: 4100-4103.

Takatori, N., Kumano, G., Saiga, H. and Nishida, H. 2010. Segregation of germ layer fates by nuclear migration-dependent localization of Not mRNA. Developmental Cell 19: 589-598.

Tamilselvi, M., Sivakumar, V., Ali, H. A. J. and Thilaga, R. D. 2010. Preparation of pickle from Herdmania pallida, simple ascidian. World Journal of Dairy & Food Sciences 5: 88-92.

Tatián, M. and Lagger, C. 2010. Ascidiacea. In Fauna Marina Bentónica de la Patagonia Chilena”/”Marine Benthic Fauna of Chilean Patagonia". Häussermann, V. and Forsterra, G. Nature in Focus, ISBN 978-956-332-243-9/ 978-956-332-244-6, Santiago, Chile. 1000 pp.

Tatián, M., Schwindt, E., Lagger, C. and Varela, M. M. 2010. Colonization of Patagonian harbours (SW Atlantic) by an invasive sea squirt (Chordata, Ascidiacea). Spixiana 33: 111-117. [Ascidiella aspersa]

Terakado, K. 2010. Generation of prolactin-like neurons in the dorsal strand of ascidians. Zoological Science 27: 581–588.

Terakubo, H. Q., Nakajima, Y., Sasakura, Y., Horie, T., Konno, A., Takahashi, H., Inaba, K., Hotta, K. and Oka, K. 2010. Network structure of projections extending from peripheral neurons in the tunic of ascidian larva. Developmental Dynamics 239: 2278-2287.

Tetsukawa, A., Nakamura, J. and Fujiwara, S. 2010. Identification of chondroitin/dermatan sulfotransferases in the protochordate, Ciona intestinalis. Comparative Biochemistry and Physiology B 157: 205-212.

Tovar-Hernández, M. A., Suárez-Morales, E. and Yáńez-Rivera, B. 2010. The parasitic copepod Haplostomides hawaiiensis (Cyclopoida) from the invasive ascidian Polyclinum constellatum in the southern Gulf of California. Bulletin of Marine Science 86: 637-648.

Tsagkogeorga, G., Turon, X., Galtier, N., Douzery, E. J. P. and Delsuc, F. 2010. Accelerated evolutionary rate of housekeeping genes in tunicates. Journal of Molecular Evolution 71: 153–167.

Willis, J. E., Stewart-Clark, S., Greenwood, S. J., Davidson, J. and Quijon, P. 2011. A PCR-based assay to facilitate early detection of Diplosoma listerianum in Atlantic Canada. Aquatic Invasions 6: in press.

Yamada, S., Ueno, N., Satoh, N. and Takahashi, H. 2010. Ciona intestinalis Noto4 contains a phosphotyrosine interaction domain and is involved in the midline intercalation of notochord cells. International Journal of Developmental Biology epub.

Yin, S., Cullinane, C., Carroll, A. R., Quinn, R. J. and Davis, R. A. 2010. Botryllamides K and L, new tyrosine derivatives from the Australian ascidian Aplidium altarium. Tetrahedron Letters 51: 3403-3405.

Yin, S., Boyle, G. M., Carroll, A. R., Kotiw, M., Dearnaley, J., Quinn, R. J. and Davis, R. A. 2010. Caelestines A-D, brominated quinolinecarboxylic acids from the Australian ascidian Aplidium caelestis. Journal of Natural Products 73: 1586-1589.

Yokota, N., Harada, Y. and Sawada, H. 2010. Identification of testis-specific ubiquitin-conjugating enzyme in the ascidian Ciona intestinalis. Molecular Reproduction and Development 77: 640-647.

Yoneda, M., Nakamura, T., Murai, M. and Wada, H. 2010. Evidence for the heparin-binding ability of the ascidian Xlink domain and insight into the evolution of the Xlink domain in chordates. Journal of Molecular Evolution 71: 51-59.

Zeller, R. W. 2010. Computational analysis of Ciona intestinalis operons. Integrative and Comparative Biology 50: 75-85.

Zhan, A., Macisaac, H. J. and Cristescu, M. E. 2010. Invasion genetics of the Ciona intestinalis species complex: from regional endemism to global homogeneity. Molecular Ecology 19: 4678-4694.

Zvyagintsev, A. Y. 2003. Introduction of species into the northwestern Sea of Japan and the problem of marine fouling. Russian Journal of Marine Biology 29: S10–S21.

Zvyagintsev, A. Y., Korn, O. M. and Kulikova, V. A. 2004. Seasonal dynamics of pelagic larvae and settling of the fouling organisms in conditions of thermal pollution. Russian Journal of Marine Biology 30: 266–277.

Zvyagintsev, D., Sanamyan, K. E. and Kashenko, S. D. 2007. On the introduction of the ascidian Ciona savignyi Herdman, 1882 into Peter the Great Bay, Sea of Japan. Russian Journal of Marine Biology 33: 133-136.