Epizoic rotifers on Dreissena polymorpha in relation to biotic factors

Abstract

Mollusks represent one of the most important components of freshwater zoobenthos and their shells provide a substrate for many organisms creating epibiotic communities of predominantly facultative nature. We determined rotifer species that colonize shells of Dreissena polymorpha (Pallas, 1771) without and with presence of large Cladocera and fish, alone and together. The experiment was conducted in 12 mesocosms filled with water from the littoral zone of a eutrophic lake. The experiment involved four treatments (three replicates each): (1) control of D. polymorpha in lake water; (2) D. polymorpha in lake water with the addition of large Cladocera; (3) D. polymorpha in lake water with the addition of fish; and (4) D. polymorpha in lake water with the addition of large Cladocera plus fish. The study revealed that epizoic rotifer fauna found on D. polymorpha is relatively abundant and rich in species, different from plankton communities in the same mesocosms, and specific, that is, include species that prefer this habitat. It may also suggest that communities of epizoic rotifers are impacted by the presences of benthic predators, as well as by small fish and large crustaceans inhabiting littoral waters.

Epizoic Rotifers and Microcrustaceans on Bivalves of Different Size and Behavior

“…Ejsmont-Karabin and Karpowicz [3] provided evidence to show that epizoon communities of Rotifera on Dreissena polymorpha were more abundant and consisted of more species than epizoon on Unio tumidus [8]. We proposed that these differences could be related to the different environmental conditions.…”

“…Ejsmont-Karabin and Karpowicz [3] revealed surprisingly high densities of epizoic rotifers on Dreissena polymorpha. They showed that large cladocerans or small fish may force plankton and littoral rotifers to hide in the druses of D. polymorpha.…”

“…Mollusks serve as an excellent substratum for epizoic rotifers and microcrustaceans because epizoon is provided by additional habitat, takes advantage of the host ability to aggregate food, and is better protected against grazing [1]. There are many reports on the colonization of animals by sessile and free-swimming rotifers [2,3]. However, data on rotifer epizoon of mollusks are rare.…”

“…However, in the treatment with the presence of large cladocerans and fish the density of epizoic rotifers was lower relative to treatments without cladocerans and fish. Ejsmont-Karabin and Karpowicz [3] suggested that such refuges which are easily accessible to cladocerans or small fish may become a trap for rotifers. Similarly, macrophytes are regarded as risky areas for zooplankton due to presence of littoral predators [5,6].…”

Report of rotifer-ciliate-gastropod hyperepibiosis found on snail (Mollusca) from Goa, India

“…Several species of rotifers have been found as epizoic on various aquatic invertebrates eg. on sponges (Berzins, 1950;Bołtruszko, 201;Bołtruszko, Ejsmont-Karabin, 2013), on crustaceans (Ahlstrom, 1940;Hollowday, 1949;Chengalath, Fernando, Koste, 1973;May, 1989;Cook, Chubb, Veltkamp, 1998;De Smet, Verolet, 2016;Dražina, Korša, Špoljar, Maguire, Klobučar, 2018), on molluscs (Boltruszko, 2011, Ejsmont-Karabin, Karpowicz, 2019.…”