Table 1 Parameters of locomotion in an illuminated small arena (1 × 1 m) and large arena (2 × 2 m). For most variables, values increased when stones were added or when arena size was increased. Bonferroni adjustment of p-value was calculated by P = 0.05/10 = 0.005. Mean (± SEM) are followed by superscript numerals that indicate the significantely different test groups (as appeared in the top row) in Tukey Honest Significant Difference (HSD) test.

52.0 ± 9.7 ^2,4,5

86.7 ± 8.8¹

60.9 ± 9.5⁵

90.4 ± 9.7¹

115.6 ± 7.3^1,3

8.68; <0.0001

0.10 ± 0.02^2,3,5

0.15 ± 0.04^1,5

0.12 ± 0.02^4,5

0.18 ± 0.02^1,3,5

0.36 ± 0.12^1–4

5.68; = 0.0012

87.0 ± 31.4^2,4,5

228.6 ± 55.7^1,3,4

51.2 ± 13.9^2,4,5

146.9 ± 23.9 ^1–5

235.8 ± 48.6 ^1,3,4

7.15; = 0.0002

18.5 ± 5.5^2,4,5

41.4 ± 11.0^1,3

12.2 ± 5.0^2,4,5

38.5 ± 7.8^1,2,5

74.7 ± 25.2^1,3,4

5.81; = 0.001

5.0 ± 0.6

5.6 ± 0.4

5.5 ± 1.2

4.4 ± 0.6

3.6 ± 0.3

0.95; ns

4.9 ± 1.4^3,5

2.4 ± 0.4³

10.2 ± 2.3^1,2,4,5

3.1 ± 0.6^3,5

2.0 ± 0.3^1,3,4

5.88; = 0.0009

0.94 ± 0.22

0.43 ± 0.06

2.68 ± .1.14

0.70 ± 0.09

0.54 ± 0.06

2.51;ns

9.3 ± 1.5^2–5

22.6 ± 4.9^1,5

55.5 ± 30.8¹

20.3 ± 1.9^1,5

41.7 ± 2.8^1,2,4

3.08; = 0.0277

2.4 ± 1.1^2,4,5

19.2 ± 6.1^1,3

2.4 ± 1.1^2,4,5

12.8 ± 3.9^1,3,5

25.5 ± 7.1^1,3,4

8.99; <0.0001

-1.87 ± 0.31²

-0.99 ± 0.36²

-1.52 ± 0.19^4,5

-0.60 ± 0.16^3,5

-0.46 ± 0.09^3,4

7.68; <0.0002