Stages and rates of normal development in the holostean fish, Amia calva

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Abstract
Thirty‐one stages in the normal development of the “living fossil” bony fish, Amia calva, are morphologically defined so as to identify the length of time after fertilization. Experiments were conducted and their results recorded in a study of morphogenetic cell movements in early embryos of this species, as reported previously (Ballard, '84) and in a paper that follows this one in this volume. Rates of progress through these stages are charted at several fairly constant temperatures. External and internal cell displacements from late cleavage to early organogenesis are described from living material and serial sections. Apperarance and changes in organogenesis are also described from dissections of all later stages to the time of disappearance of the yolk and onset of feeding, and they are correlated with earlier published descriptions which were based on specimens inadequately defined by body length or time from fertilization or hatching.