| Antedon | |
|---|---|
.jpg) | |
| Antedon mediterranea | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Crinoidea |
| Order: | Comatulida |
| Family: | Antedonidae |
| Subfamily: | Antedoninae |
| Genus: | Antedon de Freminville, 1811[1] |
| Species | |
See text | |
Antedon is agenus of sessile, stemlesscrinoids. The genus first appeared in thefossil record in theCretaceous period.[2]
Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number ofcirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate.[3] There is great variability in themorphological features in antedonids found in different habitats and the main distinguishing feature among thespecies is the number of cirri.[4]
Antedon is afilter feeder, feeding on small particules within thewater colunm. Their feeding rhythms were observed and the tend to feed almost continuously.Antedon does not feed with adiurnal rhythm and they feed at all times of the day including at night. They show no proof that the feed via a tidal feeding rhythm either and even when at the bottom of the sea floor at 50 cm/s current speeds, their arms continue to flap.Antedon posture while feeding reveals an arrangement ofpinnules along the arms. These pinnules function in triplets along each side of the arm and demonstrate a triplanar arrangement characteristic.[5]
The following species are recognised in the World Register of Marine Species:[1]