Analysis of motility parameters from paddlefish and shovelnose sturgeon spermatozoa

Ninety to 100% of paddlefish Polyodon spathula were motile just after trans fer into distilled water, with a velocity of 175 mu m s(-1), a flagellar be at frequency of 50 Hz and motility lasting 406 min. Similarly. 80-95% of sh ovelnose sturgeon Scaphirhynchus platorynchus spermatozoa were motile immed iately when diluted in distilled water, with a velocity of 200 mu m s(-1), a flagellar beat frequency of 48 Hz and a period of motility of 2-3 min. In both species, after sperm dilution in a swimming solution composed of 20 m M Tris-HCl (pH 8.2) and 20 mM NaCl a majority of the samples showed 100% mo tility of spermatozoa with flagella beat-frequency of 50 Hz within the 5 s following activation and a higher velocity than in distilled water. In such a swimming medium, the time of motility was prolonged up to 9 min for padd lefish and 5 min for sturgeon and a lower proportion of sperm cells had dam age such as blebs of the flagellar membrane or curling of the flagellar tip , compared with those in distilled water. The shape of the flagellar waves changed during the motility phase, mostly through a restriction at the part of the flagellum most proximal to the head. A rotational movement of whole cells was observed for spermatozoa of both species. There were significant differences in velocity of spermatozoa between swimming media and distille d water and between paddlefish and shovelnose sturgeon. (C) 2000 The Fisher ies Society of the British Isles.