TY  - JOUR
A1  - Obertegger, Ulrike
A1  - Cieplinski, Adam
A1  - Raatz, Michael
A1  - Colangeli, Pierluigi
T1  - Switching between swimming states in rotifers - case study Keratella cochlearis
JF  - Marine and Freshwater Behaviour and Physiology
N2  - 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.
KW  - BEMOVI
KW  - dwarf males
KW  - hidden markov model
KW  - Monogononta
KW  - swimming modes
Y1  - 2018
U6  - https://doi.org/10.1080/10236244.2018.1503541
SN  - 1023-6244
SN  - 1029-0362
VL  - 51
IS  - 3
SP  - 159
EP  - 173
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Colangeli, Pierluigi
A1  - Schlägel, Ulrike E.
A1  - Obertegger, Ulrike
A1  - Petermann, Jana S.
A1  - Tiedemann, Ralph
A1  - Weithoff, Guntram
T1  - Negative phototactic response to UVR in three cosmopolitan rotifers: a video analysis approach
JF  - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica
KW  - Risk avoidance behavior
KW  - Brachionus calyciflorus
KW  - Keratella cochlearis
KW  - BEMOVI
KW  - Movement ecology
Y1  - 2018
U6  - https://doi.org/10.1007/s10750-018-3801-y
SN  - 0018-8158
SN  - 1573-5117
VL  - 844
IS  - 1
SP  - 43
EP  - 54
PB  - Springer
CY  - Dordrecht
ER  -