Image Key > Mollusca > Pteropoda
Pteropoda
Blainville 1824
Taxonomy
| Phylum |
Mollusca |
| Class |
Gastropoda |
| Subclass |
Orthogastropoda |
| Superorder |
Heterobranchia |
| Order |
Opisthobranchia |
| Suborder |
Thecosomata |
Size
- Range in size from a few mm to 1 or 2 cm.
Distinguishing characteristics
- Planktonic opisthobranch molluscs belonging to two Orders:
- Thecosomata (shelled bodies):
- Thecosome pteropds have a very thin transparent calcareous shell that can be coiled or triangular.
- The foot has two very large parapodia or wings, hence the name pteropod or wing-foot. Note that pteropod is not a formal taxonomic term.
- The wings are used for swimming as well as suspension feeding on microplankton using cilia.
- Both the shells and body are very delicate and easily damaged, and are rarely caught completely intact.
- Gymnosomata (naked bodies):
- Gymnosomes are more robust, lack a shell and the wings are much smaller, appearing as lateral lobes.
- Gymnosome pteropods are carnivorous.
Distribution
- Very common in the open ocean.
|
