U. Obertegger, A. Cieplinski, Michael Raatz, Pierluigi Colangeli
{"title":"Switching between swimming states in rotifers – case study Keratella cochlearis","authors":"U. Obertegger, A. Cieplinski, Michael Raatz, Pierluigi Colangeli","doi":"10.1080/10236244.2018.1503541","DOIUrl":null,"url":null,"abstract":"ABSTRACT Swimming is of vital importance for aquatic organisms because it determines several aspects of fitness, such as encounter rates with food, predators, and mates. Generally, rotifer swimming speed is measured by manual tracking of the swimming paths filmed in videos. Recently, an open-source package has been developed that integrates different open-source software and allows direct processing and analysis of the swimming paths of moving organisms. Here, we filmed groups of females and males of Keratella cochlearis separately and in a mixed experimental setup. We extracted movement trajectories and swimming speeds and applied the classification method random forest to assign sex to individuals of the mixed setup. Finally, we used advanced statistical methods of movement ecology, namely a hidden Markov model, to investigate swimming states of females and males. When not discriminating swimming states, females swam faster than males, while when discriminating states males swam faster. Specifically, females and males showed two main states of movement with many individuals switching between states resulting in four modes of swimming. We suggest that switching between states is related to predator avoidance. Males of K. cochlearis especially exhibited switching between turning in a restricted area and swimming over longer distances. No mating or other male–female interactions were observed. Our study elucidates the steps necessary for automatic analysis of rotifer trajectories with open-source software. Application of sophisticated software and analytical models will broaden our understanding of zooplankton ecology from the individual to the population level.","PeriodicalId":18210,"journal":{"name":"Marine and Freshwater Behaviour and Physiology","volume":"70 1","pages":"159 - 173"},"PeriodicalIF":0.9000,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"10","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Marine and Freshwater Behaviour and Physiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1080/10236244.2018.1503541","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MARINE & FRESHWATER BIOLOGY","Score":null,"Total":0}
引用次数: 10
Abstract
ABSTRACT Swimming is of vital importance for aquatic organisms because it determines several aspects of fitness, such as encounter rates with food, predators, and mates. Generally, rotifer swimming speed is measured by manual tracking of the swimming paths filmed in videos. Recently, an open-source package has been developed that integrates different open-source software and allows direct processing and analysis of the swimming paths of moving organisms. Here, we filmed groups of females and males of Keratella cochlearis separately and in a mixed experimental setup. We extracted movement trajectories and swimming speeds and applied the classification method random forest to assign sex to individuals of the mixed setup. Finally, we used advanced statistical methods of movement ecology, namely a hidden Markov model, to investigate swimming states of females and males. When not discriminating swimming states, females swam faster than males, while when discriminating states males swam faster. Specifically, females and males showed two main states of movement with many individuals switching between states resulting in four modes of swimming. We suggest that switching between states is related to predator avoidance. Males of K. cochlearis especially exhibited switching between turning in a restricted area and swimming over longer distances. No mating or other male–female interactions were observed. Our study elucidates the steps necessary for automatic analysis of rotifer trajectories with open-source software. Application of sophisticated software and analytical models will broaden our understanding of zooplankton ecology from the individual to the population level.
期刊介绍:
Marine and Freshwater Behaviour and Physiology is devoted to the publication of papers covering field and laboratory research into all aspects of the behaviour and physiology of all marine and freshwater animals within the contexts of ecology, evolution and conservation.
As the living resources of the world’s oceans, rivers and lakes are attracting increasing attention as food sources for humans and for their role in global ecology, the journal will also publish the results of research in the areas of fisheries biology and technology where the behaviour and physiology described have clear links to the contexts mentioned above.
The journal will accept for publication Research Articles, Reviews, Rapid Communications and Technical Notes (see Instructions for authors for details). In addition, Editorials, Opinions and Book Reviews (invited and suggested) will also occasionally be published. Suggestions to the Editor-In-Chief for Special Issues are encouraged and will be considered on an ad hoc basis.
With the goal of supporting early career researchers, the journal particularly invites submissions from graduate students and post-doctoral researchers. In addition to recognising the time constraints and logistical limitations their research often faces, and their particular need for a prompt review process, accepted articles by such researchers will be given prominence within the journal (see Instructions for authors for details).