Fertilization in the sea-urchin as a function of sperm-to-egg ratio.
D000818:Animals; D005260:Female; D005306:Fertilization; D008297:Male; D008954:Models, Biological; D010063:Ovum; D012617:Sea Urchins; D012623:Seawater; D013053:Spectrophotometry; D013075:Sperm Capacitation; D013094:Spermatozoa