Changes in appendicularian Oikopleura dioica abundance caused by invasion of alien ctenophores in the Black Sea
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154; e-ISSN 1469-7769, more
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| Keywords |
Abundance
Interspecific relationships > Predation
Appendicularia [WoRMS]; Ctenophora [WoRMS]; Mnemiopsis leidyi A. Agassiz, 1865 [WoRMS]; Oikopleura (Vexillaria) dioica Fol, 1872 [WoRMS]
MED, Black Sea [Marine Regions]
Marine/Coastal |
| Abstract |
Oikopleuradioica is the only recorded appendicularian in the Black Sea. During the last two decades major changes in the O.dioica population size as well as total zooplankton community structures were recorded when invasive ctenophore species appeared in the Black Sea ecosystem. The state of the O.dioica population, before the invasion of ctenophores Mnemiopsisleidyi and Beroeovata, is reviewed. The effect of the invasion of these ctenophores on the total zooplankton and particularly on the O.dioica standing stock is summarized from our long-term data and published information. The abundance, biomass and species composition of zooplankton greatly decreased after the ctenophore Mnemiopsisleidyi invasion due to predation by M.leidyi. Specifically, the abundance of O.dioica declined at that period. But with increasing numbers of a new invader, the ctenophore Beroeovata, a predator of M.leidyi, in 1999, the zooplankton community began to recover. The population density of Oikopleuradioica also gradually increased to a level that was within the range of its abundance before the M.leidyi outbreak and even higher due to increasing its prey bacteria, which was provoked by the mucus released by B. ovata. |
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