Magelonidae
Fauchald 1977
Taxonomy
| Phylum | Annelida |
| Class | Polychaeta |
| Subclass | Palpata |
| Order | Canalipalpata |
| Suborder | Spionida |
| Family | Magelonidae |
Size
- Larvae can reach up to 4 mm.
Description
- Common benthic surface-feeders that live as burrowers in sand and mud (as adults).
Distinguishing characteristics
- Long and slender body.
- Prominent dorso-ventrally flattened spatulate prostomium.
- Two long ventrolateral palps.
- Palps have rows of adhesive papillae rather than a ciliated groove.
- Each papilla only has 2 cells (unlike adult); one has a single sensory cilium.
- Long larval chaetae.
- Asymmetrical larval tentacles.
- No eye.
Distribution
- Widely distributed throughout the world.
- Larvae of Spionidae are generally the most common developmental stages of polychaete found in plankton samples.
Ecology
- Benthic sessile or semi-sessile.
- Deposit or suspension feeders.
- Various types of development:
- pure broadcast spawning
- planktotrophic and/or lecithotrophic larvae (brooding in capsules or cocoons).
- Periods of development can be long lasting and can result in large numbers of larvae in coastal areas.
- Locomotion: Lecithotrophic larvae are weak swimmers. Planktotrophic larvae are strong swimmers (performed by propulsion by the cilia).