Preface: evolving rotifers, evolving science
The 14th International Rotifer Symposium
The 14th symposium continued the informal atmosphere of previous meetings, and the papers assembled here represent part of the research findings that were presented and discussed, or ideas that were developed during the meeting. The papers cover a wide array of research questions that are addressed using rotifers as the focal species. The most well-known model system among rotifers is the complex of cryptic and pseudo-cryptic species that goes under the name of Brachionus plicatilis Müller. This species complex is frequently used in aquaculture, as food for fish, and in ecological and evolutionary studies. As a result, several papers deal with members of this species complex, including the ecological and evolutionary consequences of its taxonomic, systematic, and nomenclatural intricacies (Gabaldón et al., 2017; Michaloudi et al., 2017; Mills et al., 2017; Riss et al., 2017), dormancy (Montero-Pau et al., 2017), population dynamics (Kamizono et al., 2017), and culture methods (Ogello et al., 2017).
Another model rotifer species that is now providing a useful comparison with B. plicatilis is Brachionus calyciflorus Pallas. Two papers in this volume cover its population dynamics (Sommer et al., 2017; Zweerus et al., 2017) and a third one a rationale for its use in eco-evolutionary studies, together with other species (Declerck & Papakostas, 2017). There are examples of other species being used as model species to solve taxonomic problems (Cieplinski et al., 2017; Wurdak, 2017), to explore the factors that affect population dynamics and adaptation (Santos-Medrano et al., 2017; Sarma et al., 2017; Walczynska et al. 2017), and to provide insight into aspects of dormancy in monogonont (Brendonck et al., 2017; García-Roger et al. 2017; Gilbert, 2017; Snell, 2017; Stelzer, 2017; Walsh et al., 2017) and bdelloid rotifers (Ricci, 2017). In addition to studies targeting individual species or groups of species, other approaches presented here address issues of community ecology and correlates of biological diversity (Lokko et al., 2017; Meyer et al., 2017; Stamou et al., 2017).
Scientometric trends in rotifer publications
Another interesting trend, highlighted in the previous meeting (Sharma et al., 2014), is the reduction in the overall number of papers published in each proceedings volume (Fig. 2B). There is a clear separation between volumes 1 (1977) to 10 (2005), with 41–72 papers each, and volumes 11 (2007) to 14 (2017), with 23–26 papers each. These differences could be due to changes in editorial processes but, when comparing the number of papers to the number of participants at each Symposium, the two groups merge and a generally decreasing trend appears (Fig. 2C). However, since 1990, the total number of papers published on rotifers outside of the symposia proceedings has increased dramatically (Fig. 2D), demonstrating that rotifer scientists have widened the horizon of their publishing activities and suggesting increased recognition of the relevance of rotifers in a broader biological context. This trend appears to be in common with other taxon-based symposia: participants publish less in the resulting proceedings, and many meetings simply do not publish proceedings anymore, because many papers are often directed at higher impact journals (Koen Martens, Editor in Chief of Hydrobiologia, personal communication).
The 638 papers published across all of the 14 proceedings illustrate well how rotifers adapt to their environment in terms of their morphology, population dynamics, community ecology, and evolution. At the same time, the clear scientometric trends show that rotifer scientists have also had to adapt to changing scientific pressures by changing the way they publish and by involving a larger number of collaborators.
- Michaloudi, E., S. Mills, S. Papakostas, C. P. Stelzer, A. Triantafyllidis, I. Kappas, K. Vasileiadou, K. Proios & T. J. Abatzopoulos, 2017. Morphological and taxonomic demarcation of Brachionus asplanchnoidis Charin within the Brachionus plicatilis cryptic species complex (Rotifera, Monogononta). Hydrobiologia. doi: 10.1007/s10750-016-2924-2.Google Scholar
- Mills, S., J. A. Alcantara-Rodriguez, J. Ciros-Pérez, A. Gómez, A. Hagiwara, K. Hinson Galindo, C. D. Jersabek, R. Malekzadeh-Viayeh, F. Leasi, J.-S. Lee, D. B. Mark Welch, S. Papakostas, S. Riss, H. Segers, M. Serra, R. Shiel, R. Smolak, T. W. Snell, C. P. Stelzer, C. Q. Tang, R. L. Wallace, D. Fontaneto & E. J. Walsh, 2017. Fifteen species in one: deciphering the Brachionus plicatilis species complex (Rotifera, Monogononta) through DNA taxonomy. Hydrobiologia. doi: 10.1007/s10750-016-2725-7.Google Scholar
- Riss, S., W. Arthofer, F. M. Steiner, B. C. Schlick-Steiner, M. Pichler, P. Stadler & C. P. Stelzer, 2017. Do genome size differences within Brachionus asplanchnoidis (Rotifera, Monogononta) cause reproductive barriers among geographic populations? Hydrobiologia. doi: 10.1007/s10750-016-2872-x.Google Scholar
- Sarma, S. S. S., M. A. Jiménez-Santos, S. Nandini & R. L. Wallace, 2017. Demography of the sessile rotifers, Limnias ceratophylli and Limnias melicerta (Rotifera: Gnesiotrocha), in relation to food (Chlorella vulgaris Beijerinck, 1890) density. Hydrobiologia. doi: 10.1007/s10750-017-3184-5.Google Scholar