6 Yolk Absorption in Embryonic and Larval Fishes
1988; Academic Press; Linguagem: Inglês
10.1016/s1546-5098(08)60203-4
ISSN1557-8011
AutoresThomas A. Heming, Randal K. Buddington,
Tópico(s)Fish Ecology and Management Studies
ResumoThis chapter discusses the yolk absorption in embryonic and larval fishes. The rate and efficiency of yolk absorption are influenced by a number of environmental factors, including temperature, light, oxygen concentration, and salinity. Fish eggs are not motile, and thus developing embryos are unable to actively exploit the most favorable environments available, at least until after hatching. In teleost eggs, the yolk syncytium together with overlaying mesoderm and ectoderm spreads to enclose the entire yolk mass. Endoderm does not follow the movement of the teleost blastodisc rim and, consequently, the yolk is not enclosed by an endodermal layer. Yolk platelets are mobilized more rapidly than the oil globule from the yolk mass, especially after hatching. The rate at which yolk reserves are depleted must be a function of the surface area of the absorptive layer and the metabolic activity of that layer.
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