Chondrophore facts for kids
Quick facts for kids Chondrophores |
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| Blue button (Porpita porpita) | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Hydrozoa |
| Order: | Anthoathecata |
| Suborder: | Capitata |
| Family: | Porpitidae Goldfuss, 1818 |
| Type genus | |
| Porpita |
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The chondrophores or porpitids are a small and unusual group of hydrozoans. They are the family Porpitidae.
They all live at the surface of the open ocean, and are colonies of carnivorous, free-floating hydroids. Their life-style in the plankton is similar to that of pelagic jellyfish.
The chondrophores look like a single organism but are cooperatives of polyps.
The most familiar members of the family Porpitidae are the blue button (Porpita porpita) and the by-the-wind sailor (Velella velella).
Structure
Chondrophores may look like a jellyfish, but they really are not. Like the siphonophores they are not a single animal. They are a colony of clones, genetically identical zooids. These zooids are small, highly modified individual polyps. Though structurally similar to other cnidarians, the zooids do not live by themselves: they are attached to each other. Each type of zooid depends for survival on the others doing what it cannot do by itself.
This kind of set-up is also found in the siphonophores: the Portuguese man o' war. They evolved independently, and are classified in different orders.
Fossil record
A rare soft-bodied fossil was got from Mississippian strata in northeastern Kentucky. It was interpreted as a chondrophorine float. The origin of the group was probably in the Neoproterozoic era, some 650–540 million years ago.
Images for kids
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Velella velella on the southern coast of Sicily.
