Glossary
Glossary
Every technical term used here, defined.
- Terms
- 1,702
- With an illustration
- 23
- Cross-references
- 66
- Used in profiles
- 1,807
4 terms beginning with Y
yolk
Substance in an animal egg consisting of protein and fat that nourishes the developing embryo.
Used in 112 profiles
yolk sac
A membranous sac containing yolk attached to the ventral surface of embryos and early larvae in some fishes. Retained for a period post-hatching in those species which form yolk sac larvae.
Used in 221 profiles
yolk sac larva
Post-hatching larval stage occurring in many fish species whereby the yolk sac remains attached to the ventral surface for a period. The larva does not feed normally until the yolk is fully-absorbed.
yolk sac viviparity
Form of livebearing in which the larvae are mostly nourished by a yolk sac which is fully-absorbed prior to birth.