Antedon is a genus of sessile, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period.[2]
Characteristics
Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri 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 the morphological features in antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri.[4]
Feeding
Antedon is a filter feeder, feeding on small particules within the water colunm. Their feeding rhythms were observed and the tend to feed almost continuously. Antedon does not feed with a diurnal 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 of pinnules along the arms. These pinnules function in triplets along each side of the arm and demonstrate a triplanar arrangement characteristic.[5]
Species
The following species are recognised in the World Register of Marine Species:[1]
- Antedon arabica AH Clark & AM Clark
- Antedon bifida (Pennant, 1777)
- Antedon duebeni Böhlsche, 1866
- Antedon mediterranea (Lamarck, 1816)
- Antedon nuttingi (AH Clark, 1936)
- Antedon parviflora (AH Clark, 1912)
- Antedon petasus (Düben & Koren, 1846)
References
- ^ a b Antedon - de Freminville, 1811 World Register of Marine Species. Retrieved 2011-10-13.
- ^ Antedon pinnulata The Fossil Museum. Retrieved 2011-10-13.
- ^ Family Antedonidae Marine Species Identification Portal. Retrieved 2011-10-13.
- ^ De Domenicoa, F.; S. Giacobbea; P. Rinellib (2009). "The genus Antedon (Crinoidea, Echinodermata) in the Strait of Messina and the nearby Tyrrhenian Sea (Central Mediterranean)". Italian Journal of Zoology. 76 (1): 70–75. doi:10.1080/11250000802086011.
- ^ La Touche, Robert W. (November 1978). "The feeding behaviour of the featherstar Antedon bifida (Echinodermata: Crinoidea)". Journal of the Marine Biological Association of the United Kingdom. 58 (4): 877–890. doi:10.1017/S0025315400056836. ISSN 1469-7769.