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Marine Biology

, Volume 123, Issue 1, pp 131–136 | Cite as

Life history of the nematode Theristus anoxybioticus from sublittoral muddy sediment at methane seepages in the northern Kattegat, Denmark

  • P. Jensen
Article

Abstract

Field and laboratory studies from 1989 to 1994 of the nematode Theristus (Penzancia) anoxybioticus Jensen, 1995 inhabiting muddy sediment at methane seepages in the northern Kattegat, Denmark, have revealed a series of biological features of adults and juveniles not observed before in free-living marine nematodes. Reproductive adults were present in April and May only and inhabited the uppermost cm of sediment, while juveniles inhabited deep anoxic and sulphidic sediment layers during the remaining months of the year. This points to a downwards migration of newly hatched juveniles and an upwards migration during adulthood. Gut content analyses showed that adults feed mainly on benthic diatoms by swallowing whole cells while juveniles probably feed on bacteria; this differentiation in food clearly relates to the main bulk of potential food items in their respective microhabitats. The generation time is estimated to be one year, with a juvenile life span of about nine months, which is four to eight times longer than that found in related aerobic species of similar body size. Adults survived in oxic water but 50% died within 15 h in hypoxic water (5 to 6% atm sat), and all died within 12 h in anoxic water. Juveniles on the other hand died within 0.5 h in oxic water but survived anoxic water for at least 15 d. These results suggest that juveniles of T. anoxybioticus are adapted to an anaerobic life style.

Keywords

Benthic Diatom Muddy Sediment Upward Migration Anoxic Water Marine Nematode 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Bouwman LA, Romeyn K, Kremer DR, van Es FB (1984) Occurrence and feeding biology of some nematode species in estuarine aufwuchscommunities. Cah Biol mar 25:287–303Google Scholar
  2. Fenchel T, Finlay BJ (1991) The biology of free-living anaerobic ciliates. Eur J Protistol 26:201–215Google Scholar
  3. Fenchel T, Finlay BJ (1995) Ecology and evolution in anoxic worlds. Oxford University Press, OxfordGoogle Scholar
  4. Gerlach SA, Schrage M (1971) Life cycles in marine meiobenthos. Experiments with Monhystera disjuncta and Theristus pertenuis. Mar Biol 9:274–281Google Scholar
  5. Heip C, Vincx M, Vranken G (1985) The ecology of marine nematodes. Oceanogr mar Biol A Rev 23:399–489Google Scholar
  6. Jensen P (1983) Meiofaunal abundance and vertical zonation in a sublittoral soft bottom, with a test of the Haps corer. Mar Biol 74:319–326Google Scholar
  7. Jensen P (1984) Ecology of benthic and epiphytic nematodes in brackish water. Hydrobiologia 108:201–217Google Scholar
  8. Jensen P (1987) Feeding ecology of free-living aquatic nematodes. Mar Ecol Prog Ser 35:187–196Google Scholar
  9. Jensen P (1995) Theristus (Penzancia) anoxybioticus n. sp. (Nematoda: Xyalidae) from sublittoral methane seepages in the northern Kattegat, Denmark. J Nematol 27:231–236Google Scholar
  10. Jensen P, Aagaard I, Burke Jr RA, Dando PR, Jørgensen NO, Kuijpers A, Laier T, O'Hara SCM, Schmaljohann R (1992) “Bubbling reefs” in the Kattegat: submarine landscapes of carbonate-cemented rocks support a diverse ecosystem at methane seeps. Mar Ecol Prog Ser 83:103–112Google Scholar
  11. Laier T, Jørgensen NO, Buchardt B, Cederberg T, Kuijpers A (1992) Accumulation and seepages of biogenic gas in northern Denmark. Contin Shelf Res 12:1173–1186Google Scholar
  12. McDowell EM, Trump BE (1976) Histologic fixative suitable for diagnostic light and electron microscopy. Archs Path 100:505–514Google Scholar
  13. Nehring S (1992) Die Vegetarier unter den freilebenden Nematoden Teil 2. Die Depositfresser. Mikrokosmos 81:259–266Google Scholar
  14. Por FD, Masry D (1968) Survival of a nematode and an oligochaete species in the anaerobic benthal of Lake Tiberias. Oikos 19:388–391Google Scholar
  15. Romeyn K, Bouwman LA (1983) Food selection and consumption by estuarine nematodes. Hydrobiol Bull 17:103–109Google Scholar
  16. Smol N, Heip C, Govaert M (1980) The life cycle of Oncholaimus oxyuris (Nematoda) in its habitat. Annls Soc r zool Belg 110:87–103Google Scholar
  17. Surey-Gent SC (1981) Distribution of Anoplostoma viviparum (Nematoda) in Southampton water sediments. Mar Biol 62:157–160Google Scholar
  18. Wieser W, Ott J, Schiemer F, Gnaiger E (1974) An ecophysiological study of some meiofauna species inhabiting a sandy beach at Bermuda. Mar Biol 26:235–248Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • P. Jensen
    • 1
  1. 1.Marine Biological LaboratoryUniversity of CopenhagenHelsingørDenmark

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