Analysis of morphometric characterisics and construction of trajectories of heterotrophic dinoflagellate oxyrrhis marina locomotion using r scripts

A.M. Lyakh

A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS,

RF, Sevastopol, Nakhimov Av., 2

DOI: 10.33075/2220-5861-2024-1-103-111

UDC 582.251+58.087+004.42           



An algorithm for evaluation of morphometric parameters and constructing trajectories of microorganisms’ locomotion such as heterotrophic dinoflagellate Oxyrrhis marina as well as food items it feeds on under experimental conditions: microalgae Isochrysis galbana and plastic microspheres is described. The algorithm operates on pre-processed video of microobjects’locomation in a water sample, separated into black-and-white frames. On each frame, the algorithm evaluates morphometric characteristics of the object images (spots) – area in pixels, length of the major axis of the described ellipse and described circle. It selects those morphometric characteristics that represent images of microorganisms or plastic microspheres, and removes the other spots. It finds spots that match or are located nearby on neighboring frames, and combines their centers into a trajectory of the spot movement. The algorithm operates automatically. It is implemented as R scripts, making them independent of the operating system, and allowing one to run scripts on a server or in the cloud.

Keywords: organisms’ locomotion, flagellates, morphometry, digital image processing, trajectories of movement, computer program.

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