# Draw the arena

Aim

To define an area of interest so that EthoVision XT ignores all activity outside this area, so only movement inside the arena is tracked.

With multiple arenas within one video image, you can track more animals simultaneously and separately. Each arena is an independent replicate.

Prerequisites

▪You have calibrated the video image.

Procedure

1.Click 2. Select Shape and Draw Arena in the Arenas and Zones section.

When working with multiple arenas, click the layer for the arena you want to draw.

2.Select a shape on the Arena Settings toolbar at the top of the window by clicking it or by pressing the corresponding shortcut key.

To split an arena in quadrants automatically (for example, in a Morris water maze, or an open field), choose Create subdivided 3-point circle or Create subdivided rectangle . See Draw subdivided shapes

3.Create a shape that covers the region on the screen in which you want EthoVision XT to track the subject. Make sure the arrow point of the arena label is inside the shape you just created.

4.If you have chosen one of the subdivided options, the Add Subdivided Circle (or Rectangle) window appears.

For circular arenas, enter the number of sectors (for example, 4 for quadrants in a Morris water maze). Default =2, maximum = 50.

For rectangular arenas, enter the number of rows and columns. A total of rows x columns equal zones will be defined.

Result: In the Arenas and Zones section, a new zone group named Subdivision Zones is added, listing the new zones. See The Subdivision Zones group

Notes

▪If you do not draw an outline, the whole background image is considered as the arena.

▪If you have multiple arenas with the same size and shape, you do not have to draw each arena separately. You just draw one arena and duplicate this one. See Duplicate an arena .

▪The shape is filled with the color visible next to the arena name in the Arenas and Zones section. To change this color, click the color next to the name.

▪To create a circle or a square, select the Ellipse or Rectangle tool, respectively, and hold Shift down while you draw the shape.

▪To export the image of the arena, click the camera button on the toolbar. Give the export file a name and select a picture format (*.png, *.jpg, *.bmp, *.gif).

The image contains all layers that are currently visible. See Working with layers for how to display layers.

▪For an experiment in DanioVision mode, EthoVision XT can detect the arenas automatically. See the DanioVision DVOC-0041 - Reference Manual.

▪You cannot delete an arena that has been used for acquisition; it has become ‘read-only’. To edit it for future tracks, duplicate the arena, edit the copy and use these settings for acquisition.