Die Manteltiere (Tunikaten) Aspekte zu ihrer Dreigliederung

Die Manteltiere (Tunikaten) Aspekte zu ihrer Dreigliederung

MEINHARD SIMON
Jahrbuch für Goetheanismus 2001, 2001, P.264-291 | DOI: 10.18756/jfg.2001.264
Zoology | Language: German | €6
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Abstract:

The tunicates - aspects of their threefoldness

The concept of threefoldness (sense-nerve system, metabolic system, rhythmic system) is applied to the hermaphroditic tunicates with their classes Appendicularia, Thaliacea, and Ascidia.

Ascidians are sessile organisms with a tadpole-like free-swimming larvae but often with a purely asexual reproduction and represent the metabolic system. This is further emphasized by the fact that the larval notochord and nerve cord disappear in the adult form.

Appendicularians, being the smallest tunicatcs and pelagic animals and keeping the tadpole-like larval form with the notochord, nerve cord and muscle bands in the adult stage, represent the sense-nerve system. They reproduce only sexually, have just one dioecious species, and are the ancestral form of the tunicates.

Thaliaceans exhibit an obligate alternation of generations but no larval form (with one exception), as well as other rhythmic properties, such as diurnal vertical migration. Hence, they represent the rhythmic system with its mediating position between the two other classes. The three orders of the thaliaeeans, the pyrosomas, salps, and doliolids, modify the alternation of generations in conspicuous ways which, together With most typical other features, demonstrate a dynamic mediation of the threefold organization of the three classes of the tunicates within this class. This thrccfold organization is also reflected by the phylogeny of the tunicates.
 

References

  • ALLDREDGE, A. L. (1976): Appendicularians. Sci. Amer. 235: 94-102
  • ALLDREDGE, A. L. (1984): The quantitative significance of gelatinous zooplankton as pelagic mers. In: Fasham, M. J. R. (Edit), Flows of Energy and Materials in ] Ecosystems. Plenum Publ., pp. 407-433. New York
  • ALLDREDGE, A. L. & MADIN, L. P. (1982): Pelagic tunicates: unique herbiv the marinc plankton. BioScience 32: 655-663
  • ALLDREDGE, A. L. & SILVER, M. L. (1988): Characteristics, dynamics and sigr ce of marine snow. Prog. Oceanogr. 20: 41-82 BAK, R. P. M., JOENJE, M., DE ]ONG, l., LAMBRECHTS, D. Y. M. & NIEUWLAND, G. (1998): Bacterial suspension feeding by coral reef benthic organisms. Mar. Ecol. Prog. Ser. 175: 285-288
  • BARHAM, E. G. (1979): Giant larvacean houses: Observations from deep submersibles. Science 205: 1129-1 131
  • BONE, Q. (1998): The Biology of Pelagic Tunicates. Oxford University Press Oxford, England
  • BONE, Q., CARRE, C. & RYAN, K. P. (2000): The endostyle and the feeding filter in salps. J. Mar. Biol. Ass. U. K. 80: 523-534
  • CHEN, J. Y., DZIK, J., EDGECOMBE, G. D., RAMSKÖLD, L. & ZHOU, G. Q. (1995): A possible early Cambrian chordate. Nature 377: 720-722
  • DARWIN, C. (1871): The Descent of Man, and Selection in Relation to Sex. J. Murray, London, England
  • DRITS, A. V., ARASHKEVICH, E. G. & SEMENOVA, T. N. (1992): Pyrosoma at/anticum (Tunicata, Thaliacea): grazing impact on phytoplankton standing stock and role in organic carbon flux. J. Plankton Res. 14: 799-809
  • FRAZER, J. H. (1981): British Pelagic Tunicates. Cambridge University Press, Cambridge
  • GARSTANG, W. (1928): The morphology of the tunicates, and its bearings on the phylogeny of the Chordata. Q. J. Microsc. Sci. 72: 51-187
  • GRZIMEK, B. (1979: Grzimeks Tierleben, Bd. 3, S. 434-453. DTV, München
  • HAECKEL, E. (1868): Natürliche Schöpfungsgeschichte. Reimer, Berlin, Germany
  • HAMNER, W. M. & ROBINSON, B. H. (1992): In situ observations of giant appendicularians in Monterey Bay. Deep-Sea Res. 39: 1299-1313
  • HIROSE, E., KIMURA, S., ITOH, T. & NISHIKAWA, J. (1999): Tunic morphology and cellulosic components of pyrosomas, doliolids, and salps (Thaliacea, Urochordata). Biol. Bull. 196: 113-120
  • HOPCROFT, R. R. & ROFF, J. C. (1995): Zooplankton growth rates: extraordinary production by the larvacean Oikoplenm dioica in tropical waters. J. Plankton Res. 17: 205-230
  • HOPCROFT, R. R. & ROFF, J. C. (1998): Production of tropical larvaceans in Kingston Harbour, Jamaica: are we ignoring an important secondary producer? J. Plankton Res. 20: 557-569
  • JEFFERIES, R. P. S. (1986): The Ancestry of the Vertebrates. British Museum, London, England
  • KOWALEWSKI, A. O. (1867: Entwicklungsgeschichte der einfachen Ascidien. Mém. Acad. Sci. St. Petersb. (7) 10(15): 1-19
  • LAMARCK, J. (1816): Histoire naturelle des animaux sans ver‘tébres, Vol. 2. Paris
  • MADIN, L. P. (1995): Sensory ecology of salps (Tunicata, Thaliacea): More questions than answers. Mar. Fresh. Bela. Physiol. 26: 175-195
  • MILLER, R. I. & COSSON, J. (1997): Timing of sperm shedding and release of aggregates in the salp Thalia democmtica (Urochordata: Thaliacea). Mar. Biol. 129: 607-614
  • NISHINO, A. & SATOH, N. (2001): The simple tail of chordates: Phylogenetic significance of appendicularians. Genesis 29: 36-45
  • NISHINO, A., SATOU, Y., MORISAWA, M. & SATOH, N. (2000): Muscle actin genes and muscle cells in the appendicularian, Oikopleum longicauda: Phylogenetic relationships among muscle tissues in the urochordates. J. Exp. 2001. (M01. Dev. Evol.) 288: 135-150
  • PAFFENHÖFER, G.-A., ATKINSON, L. P., LEE, T. N., VERITY, P. G. & BULLUCK III, L. R. (1995): Distribution and abundance of thaliaceans and copepods off the southeastern USA. during winter. Cont. Shelf Res. 15: 255-280
  • PURCELL, J. E. & MADIN, L. P. (1991): Diel patterns of migration, feeding, and spawning by salps in the subarctic Pacific. Mar. Ecol. Prog. Ser. 73: 211-217
  • RAYMONT, J. E. G. (1983): Plankton and Productivity in the Oceans, Vol. 2: Zooplankton, 2nd edition. Pergamon Press New York
  • SATOH, N. (1994): Developmental Biology of Ascidians. Cambridge University Press Cambridge, England
  • SCHAD, W. (1977): Man and Mammals. Towards a Biology of Form. Waldorf Press New York
  • STEINER, R. (1917): Von Seelenrätseln (GA 21). Rudolf Steiner Verlag Dornach 1983
  • WADA, H. (1998): Evolutionary history of free-swimming and sessile lifestyles in urochordates as deduced from 185 rDNA molecular phylogeny. Mol. Biol. Evol. 15: 1189-1194
  • WIEBE, P. H., MADIN, L. P., HAURY, L. R., HARBISON, G. R. & PHILBIN, L. M. (1979): Diel vertical migration by Salpzz aspem and its potential for large-scale particulate organic matter transport to the deep-sea. Mar. Biol. 53: 249-255