Ascidian News*

Charles and Gretchen Lambert
Department of Biological Science
California State University Fullerton
Fullerton, California 92634
tel. (714)773-3481 Fax (714)773-3426
e-mail: or

Number 34
May 1993

During April we spent a very enjoyable 3 weeks in Japan. In Shimoda we visited with our old friend Hiroshi Watanabe and had very interesting discussions with Hirose and Yas Saito and worked on Herdmania momus with Ishii. We then attended the First Intl. Symposium on the Molecular and Cell Biology of Egg- and Embryo-Coats in Yokohama. This meeting was superbly organized by Motonori Hoshi, and his committee included many of us who work on ascidian eggs: Drs. DeSantis, Honegger, Morisawa, Yokosawa, Sawada and many graduate students. It was great to get together with so many old friends as well as to learn of the tremendous progress being made in this most active area. After the meetings we visited Mits Nakauchi in Kochi and Usa, discussed common research interests with Kaz Kawamura and his students and also Fujiwara and Sugino, followed by traveling and a visit with Nishikawa in Nagoya following which we had to return to California, classes and the reality of the workaday life.

At the end of May we begin our sabbatical leave so there will not be another AN until this time next year. From June until late August we will be working in Roscoff (Fax 33-98-29-23-24). September to late November will be spent in Villefranche-sur-Mer (Fax 33-93-76-38-93); Gretchen will present a paper at the Intl. Biomineralization Symposium in Monaco in mid November. After this we will briefly visit Dr Patricia Kott in Australia and then spend December and January at the Portobello Laboratory near Dunedin, New Zealand (Fax 64-3-478-0106. Here we will work with Pyura pachydermatina and Ascidiella aspersa. We hope to see many of you on our travels. Please continue to send to our Fullerton address your reprints, abstracts, thesis abstracts and articles for the next AN, so that we can put one together as soon as we return. We depend on your contributions. Notice that there are 6 1/2 pages of new publications in this issue!

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


New journal. Zygote: The Biology of Gametes and Early Embryos, published by Cambridge Univ. Press, has just made its debut, edited by two ascidiologists: Editor-in-chief Brian Dale and N. American Editor William Jeffery. We wish them good luck and good papers, with a goodly percentage of them being on ascidians!


Drs. N. Chadwick-Furman and I.L. Weissman, Interuniversity Inst., P.O. Box 469, Eilat, Israel (NCF) and Howard Hughes Medical Inst., Stanford Univ. Med. Sch., Stanford, CA 94305 (ILW). Life-history plasticity and senescence in the colonial ascidian Botryllus schlosseri.
Colonial marine invertebrates may exhibit extreme plasticity in life-history patterns in response to variation in environmental and other factors. We determined seasonal variation in growth, reproduction and lifespan among 4 cohorts of the colonial ascidian Botryllus schlosseri in Monterey Bay, northeastern Pacific Ocean. Colonies born during spring and summer grew exponentially as juveniles for 1.5-2 months, reproduced sexually for 1 week to 2 months, then died suddenly. Colonies born during fall and winter also grew exponentially for 3-7.5 months, then sexually reproduced for 1 week to 2.5 months and died abruptly. Life-history traits varied continuously within each cohort, and in all seasons colonies were iteroparous and sub-annual. Reproductive traits such as age and size at first reproduction, number of clutches and fecundity all varied significantly with season of birth. Rate of survivorship to first reproduction exceeded 60% except during winter when an unknown predator attacked many juveniles. The main source of mortality was internally-triggered senescence, which commenced after 1-10 weeks of continuous sexual reproduction, progressed over 1-2 weeks and led irreversibly to the death of the colony. Isolated colonies were disk-shaped, rarely shrank and did not fragment. Life-histories and morphologies observed here in the field differed from those observed during previous studies in the laboratory. Life-history plasticity in B. schlosseri appears to be regulated by 3 main environmental factors: temperature, food and space availability.

For complete abstracts of ascidian papers presented at the following recent meetings request copy of AN34.
Zool. Soc. of Japan meeting, Sendai, October 7-9, 1992. Published in Zool. Sci. 9(6), Dec. 1992.
Amer. Soc. of Zoologists meeting, Vancouver, B.C. Canada Dec. 26-30, 1992.
Western Soc. of Naturalists meeting, Newport, Oregon, Jan. 7-10, 1993.


Adesanya, S.A. et al. 1992. Brominated B-carbolines from the marine tunicate Eudistoma album. J. Nat. Prod. 55:525-527.

Ambler, R.P. & J.I. Canete 1991. Settlement and recruitment of Pyura chilensis Molina, 1782 (Urochordata: Ascidiacea) on artificial plates suspended in La Herradura Bay, Coquimbo, Chile. Rev. Biol. Mar. 26:403-413.

Barrow, R.A. & R.J. Capon 1992. Sulfolane as a natural product from the sponge/tunicate composite, Batzella sp./ Lissoclinum sp. J. Nat. Prod. 55:1330-1331.

Bayer, E. et al. 1992. Structure of the tunichrome of tunicates and its role in concentrating vanadium. Angew. Chem. Int. Ed. Engl. 31:52-54.

Becerro, M.A. & X. Turon 1992. Reproductive cycles of the ascidians Microcosmus sabatieri and Halocynthia papillosa in the northwestern Mediterranean. P.S.Z.N.I.:Mar. Ecol. 13:363-373.

Berking, S. & K. Herrmann 1990. Dicapryloylglycerol and ammonium ions induce metamorphosis of ascidian larvae. Roux's Arch. Dev. Biol. 198:430-432.

Berman, J. et al. 1992. Recent invasions of the Gulf of Maine: three contrasting ecological histories. Conserv. Biol. 6:435-441.

Bingham, B.L. 1992. Life histories in an epifaunal community: coupling of adult and larval processes. Ecology 73:2244-2259.

Burighel, P. et al. 1992. Junctional complexes of the branchia and gut of the tunicate, Pyrosoma atlanticum (Pyrosomatida, Thaliacea). Cell Tiss. Res. 267:357-364.

Buskey, E.J. 1992. Epipelagic planktonic bioluminescence in the marginal ice zone of the Greenland Sea. Mar. Biol. 113:689-698.

Calder, D.R. 1991. Vertical zonation of the hydroid Dynamena crisioides (Hydrozoa, Sertulariidae) in a mangrove ecosystem at Twin Cays, Belize. Can. J. Zool. 69:2993-2999.

Chbani, M. et al. 1993. Brominated indole alkaloids from the marine tunicate Pseudodistoma arborescens. J. Nat. Prod. 56:99-104.

Crowther, R.J. & J.R. Whittaker 1992. Structure of the caudal neural tube in an ascidian larva: vestiges of its possible evolutionary origin from a ciliated band. J. Neurobiol. 23:280-292.

D'Anniello, A., A. Vetgere & L. Padula 1992. Occurrence of free D-amino acids in the gametes, embryos, larvae and adults of the sea-squirt Ciona intestinalis. Comp. Biochem. Physiol. B. Comp. Biochem. 102:795-797.

Debitus, C., D. Laurent & M. Pais 1988. Alcaloides d'une ascidie neocaledonienne, Eudistoma fragum. J. Nat. Prod. 51:799-801.

De Silva, E.D. et al. 1992. Trididemnic acids A and B, aromatic alkaloids from the Northeastern Pacific ascidian Trididemnum sp. Tetrahedron Lett. 33:2917-2920.

Drits, A.V., E.G. Arashkevich & T.N. Semenova 1992. Pyrosoma atlanticum (Tunicata, Thaliacea): grazing impact on phytoplankton standing stock and role in organic carbon flux. J. Plankton Res. 14:799-809.

Edgar, G.J. & G.R. Cresswell 1991. Seasonal changes in hydrology and the distribution of plankton in the Bathurst Harbour estuary, southwestern Tasmania, 1988-1989. Papers and Proceedings of the Royal Society of Tasmania 125:61-72.

Evans, B.K. & R. Huntington 1992. Environmental factors affecting ventilation in the ascidian, Pyura praeputialis. J. Exp. Zool. 262:462-468.

Franzen, A. 1992. Spermatozoan ultrastructure and spermatogenesis in aplousobranch ascidians, with some phylogenetic considerations. Mar. Biol. 113:77-87.

Fujiwara, S. et al. 1993. A complementary DNA for an ascidian embryonic nuclear antigen Hgv2 encodes a protein closely related to the amphibian histone-binding protein N1. J. Biochem. 113:189-195.

Fujiwara, S. & K. Kawamura 1992. Ascidian budding as a transdifferentiation-like system: multipotent epithelium is not undifferentiated. Dev., Growth & Differ. 34:463-472.

Fujiwara, S., J.X. Shigeki & K. Kawamura 1992. One step separation of mesenchymal cells of the ascidian Polyandrocarpa misakiensis. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 13:19-26.

Fuke, M. & M. Fukumoto 1993. Correlative fine structural, behavioral, and histochemical analysis of ascidian blood cells. Acta Zool. 74:61-71.

Fukumoto, M. & T. Numakunai 1993. The acrosome and its differentiation during spermiogenesis in Halocynthia roretzi. Zool. Sci. 10:103-109.

Garg, A. et al. 1992. Endogenous DNA modifications in aquatic organisms and their probable biological significance. Comp. Biochem. Physiol. B. Comp. Biochem. 102:825-832.

Godeaux, J.E.A. 1991. On the skeletal structures of the Enteropneusta (Hemichordata). Belgian J. Zool. 121:20.

Godeaux, J. 1992. Contributions of the French-speaking Belgian biologists to the tunicate knowledge during the last 125 years. Bull. Soc. Roy. Sci. Liege 61:351-367.

Goffinet, G. & J. Godeaux 1992. Ultrastructure de l'endostyle des salpes. Rapp. Comm. int. Mer. Medit. 33:250 (summary).

Gorsky, G. et al. 1991. Midwater tunicates: are they related to the permanent front of the Ligurian Sea (NW Mediterranean)? Mar. Ecol. Prog. Ser. 74:195-204.

Hambley, T.W. et al. 1992. Cycloxazoline a cytotoxic cyclic hexapeptide from the ascidian Lissoclinum-bistratum. Tetrahedron 48:341-348.

Hamner, W.M. & B.H. Robison 1992. In situ observations of giant appendicularians in Monterey Bay [California, USA]. Deep-Sea Res. Part A, Oceanogr. Res. Pap. 39:1299-1313.

Hara, K., S. Fujiwara & K. Kawamura 1992. Retinoic acid can induce a secondary axis in developing buds of a colonial ascidian, Polyandrocarpa misakiensis. Dev., Growth & Differ. 34:437-445.

Hara, K. et al. 1993. Immunohistochemical studies of the distribution of endogenous retinoids in the budding ascidian Polyandrocarpa misakiensis. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 14:15-21.

He, X. et al. 1992. In vivo incorporation of carbon-14 phenylalanine into ascidian tunichrome. Experientia 48:367-371.

Hirata, J. & H. Michibata 1992. Electron spin resonance spectrometry of vanadium ions in the blood cells of the ascidian, Ascidia gemmata. Zool. Sci. 9:207-209.

Hirose, E. & H. Mukai 1992. An ultrastructural study on the origin of glomerulocytes, a type of blood cell in a styelid ascidian, Polyandrocarpa misakiensis. J. Morph. 211:269-273.

Holland, P.W.H. et al. 1992. An amphioxus homeobox gene: sequence conservation, spatial expression during development and insights into vertebrate evolution. Development 116:653-661.

Holmstrom, C., D. Rittschof & S. Kjelleberg 1992. Inhibition of settlement by larvae of Balanus amphitrite and Ciona intestinalis by a surface-colonizing marine bacterium. Applied & Env'l. Microbiol. 58:2111-2115.

Ishida, T. et al. 1992. Molecular conformation of ascidiacyclamide, a cytotoxic cyclic peptide from ascidian: X-ray analyses of its free form and solvate crystals. Biopolymers 32:131-143.

Kawahara, H., H. Sawada & H. Yokosawa 1992. The 26S proteasome is activated at two points in the ascidian cell cycle. FEBS 310:119-122.

Kawamura, K. & S. Fujiwara 1993. Isolation of tunicate alkaline phosphatase for the preparation of histospecific monoclonal antibodies. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 14:43-50.

Kawamura, K., S. Fujiwara & Y.M. Sugino 1991. Budding-specific lectin induced in epithelial cells is an extracellular matrix component for stem cell aggregation in tunicates. Development 113:995-1005.

Kawamura, K. & M. Nakauchi 1986. Establishment of the inland culture of the colonial ascidian, Botrylloides simodensis. Marine Fouling 6:7-14.

Kawamura, K. et al. 1991. Self-nonself recognition activity extracted from self-sterile eggs of the ascidian, Ciona intestinalis. Dev., Growth & Differ. 33:139-148.

Kawamura, K. et al. 1992. Alkaline phosphatase and peroxidase activities of blood cells in the polystyelid ascidian, Polyandrocarpa misakiensis. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 13:9-17.

Kelly, K.L., E.L. Cooper & D.A. Raftos 1992. In vitro allogeneic cytotoxicity in the solitary urochordate Styela clava. J. Exp. Zool. 262:202-208.

Kelly, K.L., E.L. Cooper & D.A. Raftos 1993. Cytokine-like activities of a humoral opsonin from the solitary urochordate Styela clava. Zool. Sci. 10:57-64.

Kiguchi, T. et al. 1992. Pseudodistomin B: revised structure and first total synthesis. Tetrahedron Lett. 33:7389-7390.

Kinzer, K.P. & J.H. Cardellina 1987. Three new B-carbolines from the Bermudian tunicate Eudistoma olivaceum. Tetrahedron Lett. 28:925-926.

Koguchi, S., Y.M. Sugino & K. Kawamura 1993. Dynamics of epithelial stem cell in the process of stolonial budding of the colonial ascidian, Perophora japonica. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 14:7-14.

Kremer, P. & L.P. Madin 1992. Particle retention efficiency of salps. J. Plankton Res. 14:1009-1015.

Kroiher, M., M. Walther & S. Berking 1992. Heat shock as inducer of metamorphosis in marine invertebrates. Roux's Arch. Dev. Biol. 201:169-172.

Kusakabe, T. et al. 1991. Temporal and spatial expression of a muscle actin gene during embryogenesis of the ascidian Halocynthia roretzi. Dev., Growth & Differ. 33:227-234.

Lambert, C.C. & D.E. Battaglia 1993. Loss of the paternal mitochondrion during fertilization. Zool. Sci. 10:31-37.

Lambert, G. 1993. Three new species of stolidobranch ascidians (Chordata: Ascidiacea) from the California continental shelf. Proc. Calif. Acad. Sci. 48:109-118.

Lapota, D., D.E. Rosenberger & S.H. Lieberman 1992. Planktonic bioluminescence in the pack ice and the marginal ice zone of the Beaufort Sea. Mar. Biol. 112:665-675.

Laval, P., J.C. Braconnot & N.L. Da Silva 1992. Deep planktonic filter-feeders found in the aphotic zone with the Cyana submersible in the Ligurian Sea (Northwest Mediterranean). Mar. Ecol. Prog. Ser. 79:235-241.

Lindquist, N., M.E. Hay & W. Fenical 1992. Defense of ascidians and their conspicuous larvae: adult vs. larval chemical defenses. Ecol. Monog. 62:547-568.

Lubbering, B., E. Niermann-Kerkenberg & D.K. Hofmann 1992. Test cells of Ascidiella aspersa: adhesion and migration behaviour during embryogenesis. Invert. Repro. & Develop. 21:241-252.

Makabe, K.W. et al. 1992. Failure of muscle myosin heavy-chain gene expression in quarter ascidian embryos developed from the secondary muscle lineage cells. Zool. Sci. 9:569-573.

Makrushin, A.V. & V.V. Khudolei 1991. Tumour as an atavistic adaptive response to environmental conditions. Zh. Obshch. Biol. 52:717-721.

Marino, R. et al. 1992. Purification and characterization of a vitelline coat lysine from Ciona intestinalis spermatozoa. Molec. Reprod. Dev. 32:383-388.

Martinucci, G.B., P. Burighel & L. Casagrande 1992. Association of intercellular junctions in the branchia of lower chordates. International Congress Electron Microscopy 3:351-352.

Martinucci, G.B. et al. 1992. Ciliary specializations in branchial stigmatal cells of protochordates. Tiss. & Cell 24:229-241.

McDonald, L.A. et al. 1992. Tawicyclamides A and B, new cyclic peptides from the ascidian Lissoclinum patella: studies on the solution- and solid-state conformations. J. Org. Chem. 57:4616-4624.

Monniot, C. 1992. Ascidies de Nouvelle-Caledonie XI. Phlebobranches et stolidobranches du plateau des Chesterfield. Bull. Mus. natl. Hist. nat., Paris 14:3-22.

Monniot, F., R. Martoja & C. Monniot 1992. Silica distribution in ascidian ovaries, a tool for systematics. Biochem. System. & Ecol. 20:541-552.

Monniot, F. et al. 1992. Opal in ascidians: a curious bioaccumulation in the ovary. Mar. Biol. 112:283-292.

Moody, C.J., C.W. Rees & R. Thomas 1992. The synthesis of ascididemnin. Tetrahedron 48:3589-3602.

Naito, T. et al. 1992. First total synthesis of pseudodistomin tetrahydroacetate. Tetrahedron Lett. 33:4033-4036.

Nakamura, A. et al. 1992. a-hydroperoxy diethyl peroxide, an unusual natural compound isolated from an ascidian (Phallusia mammillata): acute toxicity in DDY mice. Toxicol. Lett. 60:257-262.

Nakauchi, Y. & K. Maruyama 1992. Immunoblot detection of vertebrate-type of connectin (titin) in ascidian bodywall muscle and tadpole. Zool. Sci. 9:219-221.

Nishida, H. 1992. Determination of developmental fates of blastomeres in ascidian embryos. Dev., Growth & Differ. 34:253-262.

Nishida, H. 1992. Developmental potential for tissue differentiation of fully dissociated cells of the ascidian embryo. Roux's Arch. Dev. Biol. 201:81-87.

Nishida, H. 1992. Regionality of egg cytoplasm that promotes muscle differentiation in embryo of the ascidian, Halocynthia roretzi. Development 116:521-529.

Nishikata, T. 1991. Characterization of antigenic polypeptides recognized by monoclonal antibodies specific to the myoplasm of eggs of the ascidian Ciona intestinalis. Dev., Growth & Differ. 33:459-467.

Nishikata, T. & N. Satoh 1990. Specification of notochord cells in the ascidian embryo analysed with a specific monoclonal antibody. Cell Differ. & Develop. 30:43-53.

Ortolani, G. 1992. Experimental gynogenesis in the ascidians. Anim. Biol. 1:39-49.

Osman, R.W., R.B. Whitlatch & R.J. Malatesta 1992. Potential role of micro-predators in determining recruitment into a marine community. Mar. Ecol. Prog. Ser. 83:35-43.

Osman, R.W. et al. 1990. Ontogenetic changes in trophic relationships and their effects on recruitment. pp. 117-129 in Trophic Relationships in the Marine Environment, Proc. 23th Europ. Mar. Biol. Symp. ed. vol., ed. by Barnes, M. & R.N. Gibson.

Pawlik, J.R. 1992. Chemical ecology of the settlement of benthic marine invertebrates. Oceanogr. Mar. Biol. Ann. Rev. 30:273-335.

Pestarino, M. 1992. The distribution of neuropeptide Y-like immunoreactivity in the ascidian Styela plicata. Cell Mol. Biol. 38:255-262.

Petersen, J.K. & H.U. Riisgard 1992. Filtration capacity of the ascidian Ciona intestinalis and its grazing impact in a shallow fjord. Mar. Ecol. Prog. Ser. 88:9-17.

Raftos, D.A. et al. 1992. Invertebrate cytokines II: release of interleukin-1-like molecules from tunicate hemocytes stimulated with zymosan. Lymphokine Cytokine Res. 11:235-240.

Raub, M.F. et al. 1991. Clavepictines A and B: cytotoxic quinolizidines from the tunicate Clavelina picta. J. Amer. Chem. Soc. 113:3178-3180.

Raub, M.F., J.H. Cardellina & T.F. Spande 1992. The piclavines, antimicrobial indolizidines from the tunicate Clavelina picta. Tetrahedron Lett. 33:2257-2260.

Rinkevich, B. & Y. Saito 1992. Self-nonself recognition in the colonial protochordate Botryllus schlosseri from Mutsu Bay, Japan. Zool. Sci. 9:983-988.

Rinkevich, B., Y. Saito & I.L. Weissman 1993. A colonial invertebrate species that displays a hierarchy of allorecognition responses. Biol. Bull. 184:79-86.

Rinkevich, B. et al. 1992. Allogeneic responses between three remote populations of the cosmopolitan ascidian Botryllus schlosseri. Zool. Sci. 9:989-994.

Rinkevich, B. & I.L. Weissman 1992. Chimeras vs genetically homogenous individuals: potential fitness costs and benefits. Oikos 63:119-124.

Rinkvich, B. et al. 1992. Allogeneic responses between three remote populations of the cosmopolitan ascidian Botryllus schlosseri. Zool. Sci. 9:989-994.

Romanenko, L.A. & V.V. Mikhailov 1992. The nuclease activity of microorganisms associated with the sea ascidian. Mikrobiologiya 61:131-134.

Sabbadin, A., P. Burighel & G. Zaniolo 1992. Some aspects of reproduction in ascidians. pp. 103-115 in Sex Origin and Evolution, ed. vol., ed. by Dallai, R.

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

Sanamyan, K. 1992. Ascidians from the Sea of Okhotsk collected by R. V. "Novoulyanovsk". Ophelia 36:187-194.

Sawada, T., J. Zhang & E.L. Cooper 1993. Classification and characterization of hemocytes in Styela clava. Biol. Bull. 184:87-96.

Schmidt, S. et al. 1992. Relation between thorium-234 scavenging and zooplankton biomass in Mediterranean surface waters. Oceanol. Acta 15:227-230.

Scippa, S., M. de Vincentiis & K. Zierold 1993. Quantitative X-ray microanalysis of the morula cell of the blood of the ascidian Halocynthia papillosa (Stolidobranchiata). Cell Tiss. Res. 271:77-80.

Smith, V.J. & C.M. Peddie 1992. Cell cooperation during host defense in the solitary tunicate Ciona intestinalis (L.). Biol. Bull. 183:211-219.

Speksnijder, J.E. et al. 1993. Polarity and reorganization of the endoplasmic reticulum during fertilization and ooplasmic segregation in the ascidian egg. J. Cell Biol. 120:1337-1346.

Stocker, L.J. 1991. Effects of size and shape of colony on rates of fission fusion growth and mortality in a subtidal invertebrate. J. Exp. Mar. Biol. Ecol. 149:161-176.

Stoner, D. 1992. Vertical distribution of a colonial ascidian on a coral reef: the roles of larval dispersal and life-history variation. Am. Nat. 139:802-824.

Sugino, Y.M., S. Koguchi & K. Kawamura 1992. Ultrastructure of cell-to-cell contact in epidermal stolon of the ascidian, Perophora japonica. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 13:27-33.

Sugino, Y.M., Y. Tsuji & K. Kawamura 1993. An ultrastructural study of blood cells in the ascidian, Polyandrocarpa misakiensis: their classification and behavioral characteristics. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 14:33-41.

Swalla, B.J. 1992. The role of maternal factors in ascidian larval muscle development. Seminars in Developmental Biology 3:287-295.

Swalla, B.J., M.R. Badgett & W.R. Jeffery 1991. Identification of a cytoskeletal protein localized in the myoplasm of ascidian eggs localization is modified during anural development. Development 111:425-436.

Szewzyk, U. et al. 1991. Relevance of the exopolysaccharide of marine Pseudomonas sp. strain S9 for the attachment of Ciona intestinalis larvae. Mar. Ecol. Prog. Ser. 75:259-265.

Thomas, M.L.H. et al. 1992. Biotic characteristics of the anchialine ponds of Bermuda. Bull. Mar. Sci. 50:133-157.

Tosti, E. & B. Dale 1992. Lithium and phorbol ester modify the activating capacity of ascidian spermatozoa. Experientia 48:57-60.

Tsuji, Y., S. Fujiwara & K. Kawamura 1993. Ultrastructural study of developing oocytes in the budding tunicate, Polyandrocarpa misakiensis. Mem. Fac. Sci. Kochi Univ. Ser. D Biol. 14:23-31.

Ueki, T., K.W. Makabe & N. Satoh 1991. Isolation of cDNA clones for epidermis-specific genes of the ascidian embryo. Dev., Growth & Differ. 33:579-586.

Van Maarseveen, J.H. et al. 1992. Antiviral and antitumor structure-activity relationship studies on tetracyclic eudistomines. J. Med. Chem. 35:3223-3230.

VanWagenen, B.C. & J.H. Cardellina 1989. Short, efficient syntheses of the antibiotic eudistomins I and T. Tetrahedron Lett. 30:3605-3608.

Vinogradov, M.E. & E.A. Shushkina 1992. Peculiarities of meso-and macroplankton vertical distribution in the central tropical areas of the northern Pacific Ocean. Okeanologiya 32:115-127.

Vitturi, R. et al. 1991. Silver NOR and C-banding analysis of spermatocyte chromosomes of Clavelina lepadiformis (Ascidiacea, Aplousobranchiata). Caryologia 44:343-347.

Walters, L.J. 1992. Post-settlement success of the arborescent bryozoan Bugula neritina (L.): the importance of structural complexity. J. Exp. Mar. Biol. Ecol. 164:55-71.

Watters, D.J. et al. 1992. Bistratene A: a novel compound causing changes in protein phosphorylation patterns in human leukemia cells. J. Cell. Biochem. 49:417-424.

Yoshida, W.Y. et al. 1992. A complex pyrrolo-oxazinone and its iodo derivative isolated from a tunicate. Helv. Chim. Acta 75:1721-1725.

Zajac, R.N., R.B. Whitlatch & R.W. Osman 1989. Effects of inter-specific density and food supply on survivorship and growth of newly settled benthos. Mar. Ecol. Prog. Ser. 56:127-132.

Zhang, H. et al. 1992. Electron microscopic analysis of tunicate (Halocynthia roretzi) hemocytes. Zool. Sci. 9:551-562.