Schizocoelous
Encyclopedia
Schizocoely is a process by which some animal embryos develop. Animal
s which develop through schizocoely are known as schizocoelomates. Schizocoely occurs when a coelom
(body cavity) is formed by splitting the mesoderm
al embryonic tissue.
Schizocoelous development is typically attributed to protostomes: phyla Mollusca
, Annelida, and Arthropoda, but some deuterostomes can exhibit schizocoely as well.
The term refers to the order of organization of cells in the gastrula leading to development of the coelom
. In these three phyla of organisms, the mesoderm
(the middle germ layer
) forms as a solid mass of migrated cells from the single layer of the gastrula. The new mesoderm then splits, creating the pocket-like cavity of the coelom.
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s which develop through schizocoely are known as schizocoelomates. Schizocoely occurs when a coelom
Coelom
The coelom is a fluid-filled cavity formed within the mesoderm. Coeloms developed in triploblasts but were subsequently lost in several lineages. Loss of coelom is correlated with reduction in body size...
(body cavity) is formed by splitting the mesoderm
Mesoderm
In all bilaterian animals, the mesoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the ectoderm and endoderm , with the mesoderm as the middle layer between them.The mesoderm forms mesenchyme , mesothelium, non-epithelial blood corpuscles and...
al embryonic tissue.
Schizocoelous development is typically attributed to protostomes: phyla Mollusca
Mollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
, Annelida, and Arthropoda, but some deuterostomes can exhibit schizocoely as well.
The term refers to the order of organization of cells in the gastrula leading to development of the coelom
Coelom
The coelom is a fluid-filled cavity formed within the mesoderm. Coeloms developed in triploblasts but were subsequently lost in several lineages. Loss of coelom is correlated with reduction in body size...
. In these three phyla of organisms, the mesoderm
Mesoderm
In all bilaterian animals, the mesoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the ectoderm and endoderm , with the mesoderm as the middle layer between them.The mesoderm forms mesenchyme , mesothelium, non-epithelial blood corpuscles and...
(the middle germ layer
Germ layer
A germ layer, occasionally referred to as a germinal epithelium, is a group of cells, formed during animal embryogenesis. Germ layers are particularly pronounced in the vertebrates; however, all animals more complex than sponges produce two or three primary tissue layers...
) forms as a solid mass of migrated cells from the single layer of the gastrula. The new mesoderm then splits, creating the pocket-like cavity of the coelom.
External links
- Enterocoelous and schizocoelous conditions - UTM.edu