Four species of the genus Synchaeta were identified in the waters of Liepaja harbour (coastal Eastern Gotland Basin, Baltic Sea). Synchaeta baltica and S. monopus are common in the Baltic Sea and they co-dominated most of the samples. Synchaeta fennica was abundant during spring, but S. triophthalma was detected in October 2014 for the first time in Latvian waters. During sample analysis particular attention was paid to insufficiently described trophi of S. monopus and S. fennica. Subsequently, brief descriptions were made during analysis and complemented with images.
Arndt, H. 1993. Rotifers as predators on components of the microbial web (bacteria, heterotrophic flagellates, ciliates) – a review. Hydrobiologia, 255, 231–246.
https://doi.org/10.1007/BF00025844
Arndt, H., Schröder, C., and Schnese, W. 1990. Rotifers of the genus Synchaeta – an important component of the zooplankton in the coastal waters of the Southern Baltic. Limnologica (Berlin), 21, 233–235.
Berzinsh, B. 1960. Rotatoria I. Genus: Synchaeta. Conseil International Pour L’Exploration de la Mer. Zooplankton Sheet No 84.
De Smet, W. H. 1998. Preparation of rotifer trophi for light and scanning electron microscopy. Hydrobiologia, 387/388, 117–121.
https://doi.org/10.1023/A:1017053518665
Dippner, J. W., Kornilovs, G., and Sidrevics, L. 2000. Long-term variability of mesozooplankton in the Central Baltic Sea. J. Marine Syst., 25, 23–31.
https://doi.org/10.1016/S0924-7963(00)00006-3
Dolan, J. R. and Gallegos, C. C. 1992. Trophic role of planktonic rotifers in the Rhode River Estuary, spring–summer 1991. Mar. Ecol. Prog. Ser., 85, 187–199.
https://doi.org/10.3354/meps085187
Fontaneto, D., De Smet, W. H., and Ricci, C. 2006. Rotifers in saltwater environments, re-evaluation of an inconspicuous taxon. J. Mar. Biol. Ass. U.K., 86, 623–656.
https://doi.org/10.1017/S0025315406013531
HELCOM. 2013. Joint HELCOM/OSPAR Guidelines for the Contracting Parties of OSPAR and HELCOM on the granting of exemptions under International Convention for the Control and Management of Ships’ Ballast Water and Sediments, Regulation A-4. HELCOM Ministerial Declaration.
Hollowday, E. D. 2002. Family Synchaetidae Hudson & Gosse, 1886. In Guides to the Identification of the Microinvertebrates. ROTIFERA. Vol. 6 (Nograndy, T. and Segers, H., eds), pp. 87–264. Backhuys Publishers, Leiden.
Hudson, C. T and Gosse, P. H. 1886. The Rotifera: or, Wheel-Animalcules. With illustrations. In two volumes. Longmans, Green, and Co, London.
IOW Press Release. 2014. A small wave of relief: oxygen measured in the deep water of the Baltic Proper. http://www.io-warnemuende.de/tl_files/news/presse/ 2014/20140807_presse_Salzwassereinbruch_english.pdf (accessed 2016-10-15).
Ikauniece, A. 2001. Long-term abundance dynamics of coastal zooplankton in the Gulf of Riga. Environ. Int., 26, 175–181.
https://doi.org/10.1016/S0160-4120(00)00094-5
Johansson, S. 1983. Annual dynamics and production of rotifers in an eutrophication gradient in the Baltic Sea. Hydrobiologia, 104, 335–340.
https://doi.org/10.1007/BF00045987
Johansson, S. 1992. Regulating Factors for Coastal Zooplankton Community Structure in the Northern Baltic Proper. Doctoral Thesis. University of Stockholm.
Kornilovs, G., Möllmann, C., Sidrevics, L., and Berzinsh, V. 2004. Fish predation modified climate-induced long-term trends of mesozooplankton in a semi-enclosed coastal gulf. In ICES CM 2004/L:13, pp. 1–26.
Koste, W. 1978. Rotatoria. Die Rädertiere Mitteleuropas. Ein Bestimmungswerk begründet von Max Voigt. In two volumes. Borntraeger, Berlin.
Kutikova, L. A. 1970. Kolovratki fauny SSSR (Rotatoria). Akademia Nauk SSSR, Leningrad (in Russian).
Lokko, K., Virro, T., and Kotta, J. 2014. Taxonomic composition of zoopsammon in fresh and brackish waters of Estonia, a Baltic province ecoregion of Europe. Estonian J. Ecol., 63, 242–261.
https://doi.org/10.3176/eco.2014.4.04
Mironova, E., Telesh, I., and Skarlato, S. 2008. Biodiversity of microzooplankton (ciliates and rotifers) in the Baltic Sea. In US/EU-Baltic International Symposium, 2008 IEEE/OES. Conference Paper. doi: 10.1109/ BALTIC.2008.4625505.
Obertegger, U., Braioni, M. G., Arrighetti, G., and Flaim, G. 2006. Trophi morphology and its usefulness for identification of formalin-preserved species of Synchaeta Ehrenberg, 1832 (Rotifera: Monogononta: Synchaetidae). Zool. Anz., 245, 109–120.
https://doi.org/10.1016/j.jcz.2006.05.005
Ojaveer, E., Lumberg, A., and Ojaveer, H. 1998. Highlights of zooplankton dynamics in Estonian waters (Baltic Sea). ICES J. Mar. Sci., 55, 748–755.
https://doi.org/10.1006/jmsc.1998.0393
Ojaveer, H., Jaanus, A., MacKenzie, B. R., Martin, G., Olenin, S., Radziejewska, T., et. al. 2010. Status of biodiversity in the Baltic Sea. PLoS ONE, 5(9), e12467.
https://doi.org/10.1371/journal.pone.0012467
Rougier, C., Pourriot, R., and Lam-Hoai, T. 2000. The genus Synchaeta (rotifers) in a north-western Mediterranean coastal lagoon (Etang de Thau, France): taxonomical and ecological remarks. Hydrobiologia, 436, 105–117.
https://doi.org/10.1023/A:1026579212772
Ruttner-Kolisko, A. 1974. Plankton Rotifers. Biology and Taxonomy. Supplementary edition. Schweizerbart, Stuttgart.
Stoecker, D. K. and Egloff, D. A. 1987. Predation by Acartia tonsa Dana on planktonic ciliates and rotifers. J. Exp. Mar. Biol. Ecol., 110, 53–68.
https://doi.org/10.1016/0022-0981(87)90066-9
Telesh, I. and Heerkloss, R. 2002. Atlas of Estuarine Zooplankton of the Southern and Eastern Baltic Sea. Verlag Dr. Kovač, Hamburg.
Telesh, I., Postel, L., Heerkloss, R., Mironova, E., and Skarlato, S. 2009. Zooplankton of the Open Baltic Sea: Extended Atlas. BMB Publication No. 21 – Meereswissenschaftliche Berichte, Warnemünde, 76.
Werner, I. and Auel, H. 2004. Environmental conditions and overwintering strategies of planktonic metazoans in and below coastal fast ice in the Gulf of Finland (Baltic Sea). Sarsia, 89, 102–116.
https://doi.org/10.1080/00364820410003504
Williamson, C. E. 1987. Predator–prey interactions between omnivorous diaptomid copepods and rotifers: the role of morphology and behaviour. Limnol. Oceanogr., 32, 167–177.
https://doi.org/10.4319/lo.1987.32.1.0167
https://doi.org/10.4319/lo.1986.31.2.0393
