Table 1.

Motility characteristics of the different sperm subpopulations.

	Motility characteristics of sperm
	within a cluster
Cluster.	VCL [μm/s]	LIN	ALH [μm]	BCF [Hz]	% Sperm
no.
1	76.8 ± 21.3	0.69 ± 0.11	1.47 ± 0.54	38.4 ± 9.4	44.2
2	128.0 ± 25.4	0.46 ± 0.09	2.74 ± 0.84	44.2 ± 7.8	13.5
3	137.0 ± 29.3	0.76 ± 0.11	2.20 ± 0.83	44.4 ± 7.5	7.9
4	37.2 ± 12.0	0.51 ± 0.13	1.17 ± 0.57	13.5 ± 7.9	8.5
5	76.9 ± 21.5	0.40 ± 0.08	2.14 ± 0.76	36.2 ± 8.6	5.3
6	135.6 ± 26.1	0.26 ± 0.06	2.76 ± 0.79	43.5 ± 7.6	3.4
7	19.8 ± 7.8	0.84 ± 0.11	0.75 ± 0.67	0.5 ± 1.8	1.8
Rest					15.5

Subpopulations of sperm (cluster) with different motility characteristics as detected through cluster analysis. The analysis was based on 33,229 sperm tracks after a 30-min incubation period at 38°C after 24, 72, and 120 h of storage. Only clusters containing more than 5 % of spermatozoa at least at one of the storage times by temperature combinations are listed (c.f. Figure 3). Motility descriptors (mean ± standard deviation) are given for each cluster as well as the percentage of sperm assigned to each cluster.

VCL, curvilinear velocity; LIN, linearity (VSL/VCL); ALH, average amplitude of lateral head-displacement; BCF, beat cross frequency.