Comparing the EthoVision 2.3 system and a new computerized multitracking prototype system to measure the swimming behavior in fry fish

Abstract

Coming from the framework of unmarked fry tracking, we compared the capacities, advantages, and disadvantages of two recent video tracking systems: EthoVision 2.3 and a new prototype of multitracking. The EthoVision system has proved to be impressive for tracking a fry using the detection by gray scaling. Detection by subtraction has given less accurate results. Our video multitracking system is able to detect and track more than 100 unmarked fish by gray scaling technique. It permits an analysis at the group level as well as at the individual level. The multitracking program is able to attribute a number to each fish and to follow each one for the whole duration of the track. Our system permits the analysis of the movement of each individual, even if the trajectories of two fish cross each other. This is possible thanks to the theoretical estimation of the trajectory of each fish, which can be compared with the real trajectory (analysis with feedback). However, the period of the track is limited for our system (about 1 min), whereas EthoVision is able to track for numerous hours. In spite of these limitations, these two systems allow an almost continuous automatic sampling of the movement behaviors during the track.

The use of visual and automatized behavioral markers to assess methodologies: a study case on PIT-tagging in the Alpine newt

“…The use of a newly developed video-tracking software (Ethovision® XT 7) allowed us to quantify variables such as distance, movement, and velocity. This computerized method has an advantage over standard visual methods in that it determines in a very accurate way the position of an individual and allows processing of a large amount of data in a relatively short time period (Delcourt et al, 2006;Delcourt et al, 2009;Eddins et al, 2010). Both methods proved to be complementary with respect to each other in analyzing different behavioral aspects: Visual observations assess complex behaviors such as feeding and breeding, while video tracking assesses more quantitative patterns of locomotor activity.…”

Daily activity rhythms of the African catfishHeterobranchus longifilis(Clariidae) in an experimental enclosure

“…21, 419-422 (2008) The method used in these experiments did not allow us to collect data such as the speed or duration of swimming behaviour and the time fish passed at a given place in the aquarium. New video-tracking systems can be used in this aim (Ylieff and Poncin 2003;Delcourt et al 2006) and should thereby improve the subsequent study of biological rhythms in fish.…”

Video tracking in the extreme: A new possibility for tracking nocturnal underwater transparent animals with fluorescent elastomer tags

“…Tracking several individuals on the basis of spot size is only possible using grayscaling and subtraction detections 2 (two other detection methods used by the EthoVision system for noncolored movies; Delcourt et al, 2006;Noldus et al, 2001). However, any detection that combines color and size characteristics is difficult if the animal can move in three spatial dimensions, because the size of the spot in the image can vary greatly.…”