All's good in a famine? Hydrobia ulvae as a secondary prey for juveniles of Iceland moonsnails Amauropsis islandica at the White Sea sandflats
Aristov, D.; Varfolomeeva, M.; Puzachenko, G. (2015). All's good in a famine? Hydrobia ulvae as a secondary prey for juveniles of Iceland moonsnails Amauropsis islandica at the White Sea sandflats. J. Mar. Biol. Ass. U.K. 95(8): 1601-1606. https://dx.doi.org/10.1017/S0025315415000454 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 Also appears in:Sukhotin, A.; Frost, M.; Hummel, H. (Ed.) (2015). Proceedings of the 49th European Marine Biology Symposium September 8-12, 2014, St. Petersburg, Russia. European Marine Biology Symposia, 49. Journal of the Marine Biological Association of the United Kingdom, 95(8). 1517-1721 pp., more |  |
| Keyword | | | Author keywords | caging experiments; ontogenetic diet shift; prey switching; boreholes;Naticidae; predator-prey interactions; Amauropsis islandica; Hydrobiaulvae; Macoma balthica; White Sea |
| Authors | | Top | - Aristov, D.
- Varfolomeeva, M.
- Puzachenko, G.
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| Abstract | Many size-selective predators switch their diet during ontogeny. At the White Sea, the adult moonsnails Amauropsis islandica feed mostly on Macoma balthica clams. The diet of juveniles was largely unknown. We conducted a field survey and a caging experiment to find out if juvenile moonsnails can prey on Hydrobia ulvae, and whether they prefer this snail to their usual prey. Live molluscs and their intact or perforated shells were collected from 34 sediment cores. We exposed the single-prey cages with 50 Macoma (MP) or 50 Hydrobia (HP) together with five Amauropsis juveniles, as well as the cages where both prey species were in a 25:25 proportion (HMP). While live Hydrobia was more abundant in the natural assemblages, Amauropsis preferred Macoma, as indicated by proportions of perforated shells. The caging experiment produced similar results. Per capita Macoma consumption rate was significantly higher than Hydrobia consumption rate (6.4 ± 0.5 mg day-1 ind.-1vs. 1.4±0.2 mg day-1 ind.-1 in MP and HP respectively). Prey consumption rates in the single-prey treatments were higher than in mixed-prey cages regardless of prey species. Different mechanisms explain this variation: for Hydrobia it is a consequence of the dietary shift, while for Macoma it reflects the ‘floor’ effect in HMP cages, where virtually all Macoma had been drilled by the end of exposure term. While Macoma is the preferable prey of young Amauropsis, Hydrobia can supplement the diet of juveniles when Macoma is scarce in certain locations. |
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