title: An ultrastrutural investigation on preliminaries in fertilization of Ascidia malaca (Urochordata).
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization; D008297:Male; D010063:Ovum / Q000648:ultrastructure*; D013094:Spermatozoa / Q000648:ultrastructure*; D014561:Urochordata / Q000502:physiology*; D015053:Zygote / Q000648:ultrastructure