Halocladius variabilis(Diptera: Chironomidae): a marine insect symbiotic with seaweeds from the White Sea, Russia

Abstract

The commensal (and possibly mutualistic) symbiosis between the marine chironomid,Halocladius variabilis, and brown algal epiphytes ofFucus vesiculosusandAscophyllum nodosumis described for the first time from Europe, based on field studies from the White Sea, Russia. While the primary host,Elachista fucicola, and the secondary host,A. nodosum, are the same as in eastern Canada where the symbiosis was first described, White Sea populations have a wider range of primary hosts that includePylaiella littoralisandDictyosiphon foeniculaceus. About 64% ofE. fucicolathalli onA. nodosumin the low intertidal zone were colonized. Significantly lower frequencies were found onE. fucicolawhen the latter was epiphytic onF. vesiculosusat the same tidal height or on either secondary host when they were in the subtidal zone. For a given tidal height, or secondary host, frequency ofH. variabiliswas reduced onP. littoralisand further reduced onD. foeniculaceus. We suggest that subtidal populations are colonized by dispersal of larvae from the intertidal zone on to suitable substrata, and that there is limited potential for these individuals to reach the intertidal zone as adults for reproduction.

The first Arctic conspicuously coloured Pleusymtes (Crustacea: Amphipoda: Pleustidae) associated with sea anemones in the Barents Sea

“…Unfortunately, trawl sampling does not reveal such associations. However, the species that are symbiotic or potentially could be symbionts of other larger invertebrates are recorded in the Arctic (e.g., Averincev 1990;Ho & Ivanenko 2003;Kutz et al 2005;Yamaguchi 2006;Tarakhovskaya & Garbary 2009;Tandberg et al 2010;Marin & Sinelnikov 2017;Vader & Tandberg 2020;Marin & Antokhina 2020). Quite a few obligately (permanent) anemone-associated species are known in Arctic and sub-Arctic waters (see Table 1), while all known representatives of the amphipod family Pleustidae are identified only at the generic level.…”

Host selection by larvae of a marine insectHalocladius variabilis: nutritional dependency or escape from predation?

“…When we began this study we recognized the possibility that apparent host fidelity of larvae to Elachista may be explained simply as a consequence of adult H. variabilis ovipositing egg masses in this host. Elachista is the only host where egg masses have been found (Garbary et al , 2009; Tarakhovskaya & Garbary, 2009; Brown & Garbary, 2010) and additional experiments would clarify the adaptive basis of this association. Namely, is the association based on the abundance of Elachista at appropriate tidal elevations, or does this host provide security for those egg masses (i.e.…”

Marine macroalgae and associated flowering plants from the Keret Archipelago, White Sea, Russia

“…Preliminary works by Balashova et al (2005) and Mikhaylova (2010) provide floristic background material for the Keret Archipelago and the White Sea as a whole. This is supplemented by ecological (e.g., Myagkov 1975, Tarakhovskaya and Garbary 2009, Maximova and Sazhin 2010, and physiological studies for the region (e.g., Maslov 2005, Berger 2009). …”

“…This is a common epiphyte of Fucus vesiculosus and A. nodosum. Like Nova Scotia, it seems to be the preferred habitat for the marine chironomid Halocladius variabilis (Garbary et al 2009, Tarakhovskaya and.…”