Publication Date:
2022-06-01
Description:
Following a mass mortality of the demersal fish population in Kiel Fjord due to anoxic water conditions throughout the water column, the occurrence of mass aggregations of the free-living marine nematode Pontonema vulgare on dead fish, jellyfish (Aurelia aurita, Cyanea capillata) and starfish (Asterias rubens), and in weakened mussels (Mytilus edulis) was observed by SCUBA diving and documented through underwater photography as early as two days after the incident occurred. P. vulgare not only survived the anoxic conditions which prevailed for severals days, but also took advantage of these circumstances to prey upon dead or weakened animals on the sediment. These observations confirm previous reports of a possible role of Pontonema vulgare as a scavenger in the form of mass aggregations in areas of acute oxygen depletion and sediments of high organic content. Positive thigmotaxis is assumed to cause aggregations of Pontonema vulgare upon brown sediments and on webs of Beggiatoa spec. in oxic water with no apparent prey as a cause. Their chemoreceptive sense, thigmotactic aggregation behavior, ability to withstand adverse oxygen conditions, and their broad feeding spectrum are responsible for the success of this species in an extreme environment.
Type:
Article
,
NonPeerReviewed
Format:
text
