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Definition

noun

(embryology) The incomplete cleavage in telolecithal or megalecithal eggs of animals, such as birds and reptiles.

Supplement

Depending mostly on the amount of yolk in the egg, cleavage can be holoblastic (complete or total) or meroblastic (partial).

In meroblastic cleavage, only a portion of the egg divides. This is because of the large amount of yolk in the egg cell that the cleavage furrows do not penetrate the yolk.

Two major types of meroblastic cleavage:

• discoidal cleavage
• superficial cleavage

Synonyms:

• incompete cleavage
• partial cleavage

Compare: holoblastic cleavage