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Summary Stage Literature (344) Attributions Wiki

Name: NF stage 40

XAO ID: 1000052

Definition: "Nieuwkoop and Faber stage 40, corresponding to an embryo of age 2 days, 18 hr at 22-24 Celsius and having the following external morphological criteria: Mouth broken through. Length of gills about twice their breadth, posterior one sometimes also showing a branch. Outlines of proctodeum and tail myotomes forming angles of 90 degrees. Beginning of blood circulation in gills. Length: 6.3 - 6.8 mm."

Preceded By: NF stage 39 Succeeded By: NF stage 41