Articles on this page are available in 1 other language: Spanish (1) (learn more)

Overview

Distribution

O. validus is distributed throughout Antarctica and the Antarctic Peninsula, South Shetland Islands, South Orkney Islands, South Sandwich Islands, South Georgia Island, Shag Rocks, Marion and Prince Edward Islands, and Bouvet Island at depths from 0 to 914 meters (Clark, 1962; Clark, 1963; Bernasconi, 1970)
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Depth range based on 119 specimens in 1 taxon.
Water temperature and chemistry ranges based on 78 samples.

Environmental ranges
  Depth range (m): 0 - 2902
  Temperature range (°C): -1.951 - 12.221
  Nitrate (umol/L): 6.335 - 36.002
  Salinity (PPS): 33.660 - 35.088
  Oxygen (ml/l): 4.036 - 8.053
  Phosphate (umol/l): 0.761 - 2.502
  Silicate (umol/l): 2.840 - 135.683

Graphical representation

Depth range (m): 0 - 2902

Temperature range (°C): -1.951 - 12.221

Nitrate (umol/L): 6.335 - 36.002

Salinity (PPS): 33.660 - 35.088

Oxygen (ml/l): 4.036 - 8.053

Phosphate (umol/l): 0.761 - 2.502

Silicate (umol/l): 2.840 - 135.683
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Dispersal

The starfish O. validus has a demersal feeding larva with a brief pelagic phase to allow the dispersion without exposing the larvae to the hazardous surface waters.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Trophic Strategy

O. validus is an omnivorous. Its diet includes the bivalves Limatula hodgsoni and Laternula elliptica, the sponges Rossella racovitzae, Rossella nuda, Scolymastra joubini, Tetilla leptoderma, and Homaxinella balfourensis, the hydroid Halecium arboreum, the sea star Acodontaster conspicuus, the sea urchin Sterechinus neumayeri, the isopod Glyptonotus antarcticus, bryozoans, suspended matter, animal dtritus, red algae, amphipods, crustacean nauplii larvae, ostracods, shrimp, ectoprocts, diatoms, and seal feces (Conlan et al., 2006).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Associations

O. validus is prey of the sea anemone Urticinopsis antarcticus and the sea star Macroptycaster accrescens (Conlan et al., 2006).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

General Ecology

Odontaster validus is the commonest and most abundant sea star inhabiting the shallow environment around the Antarctic continent (Dearborn, 1977; McClintock et al., 1988).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life History and Behavior

Life Cycle

The larval development of Odontaster is extremely slow; it remains in the bipinnaria larval stage for about 2 months in the laboratory condition (Chia, 1970). In McMurdo Sound the period of spawning is from June to mid October (Pearse et al., 1986; Bosch & Pearse, 1990).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life Expectancy

O. validus may live for about 100 years (Pearse, 1969).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Growth

Odontaster validus has a late sexual maturity and slow rate of growth. This starfish may grow only 1-2 g year-1, takes 3-6 years to reach sexual maturity (Pearse, 1969).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Stefano Schiaparelli

Partner Web Site: Census of Antarctic Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Barcode data: Odontaster validus

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Statistics of barcoding coverage: Odontaster validus

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 2
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Wikipedia

Odontaster validus

Odontaster validus is a species of starfish in the family Odontasteridae. Its range includes the Southern Ocean and the seas around the mainland and islands of Antarctica.

Description[edit]

Odontaster validus can grow to about 10 cm (4 in) in diameter. The disc is broad, thick and cushion-like, creased by interambulacral grooves. There is a large madreporite near the centre and the surface is covered in small granulations organised in radial rows. The five short arms are wide at the base tapering sharply and the tip is often raised off the substrate showing the pale coloured tube feet beneath. The colour of the upper or aboral surface is plain red while the underside is pink.[1]

Distribution[edit]

Odontaster validus is the commonest starfish found in Antarctica. Its range includes the Antarctic Peninsula, the South Shetland Islands, the South Orkney Islands, South Georgia and the South Sandwich Islands, the Shag Rocks, the Prince Edward Islands and Bouvet Island. It is found at depths down to 900 metres.[2]

Biology[edit]

Odontaster validus is an omivorous scavenger and consumes anything it finds including carrion, detritus, the faeces of seals, red algae, bivalve shells, sponges, hydroids, other starfish, sea urchins, isopods, bryozoans, amphipods, crustacean larvae, ostracods, shrimps and diatoms.[2] They have been observed aggregating on banks of mussels that have been exposed and damaged and on injured starfish, Acodontaster conspicuus.[3] In turn, they are preyed upon by sea anemones and other species of starfish.[2] It is an ecologically important species because of its consumption of benthic larvae and the control it exerts on the starfish Acodontaster conspicuus and the nudibranch Doris spp. which themselves tend to limit the growth of sponges that tend to dominate the seabed.[4]

Odontaster validus takes 3 to 6 years to reach maturity but may live for 100 years.[2] This is a consequence of the animal being cold-blooded, the harsh environmental conditions in which it lives and the low metabolic rate that ensues.[2] In McMurdo Sound, where it has been extensively studied, the water temperature is about −1.8 °C (28.8 °F).[5] The initiation of oogenesis occurs from August to February and the eggs take about 18 months to mature. Spawning takes place between May and September and may be linked to seasonal changes in light levels, sunrise taking place in McMurdo Sound in August.[5] The larval development is also slow with the first, bipinnaria, stage lasting 2 months. The larvae remain near the seabed during this time but become pelagic for up to 6 months as brachiolaria larvae which allows them to disperse widely. They then return to the seabed, undergo metamorphosis and develop into juvenile starfish.[2]

Research[edit]

Odontaster validus does not attack members of its own species but can attack starfish of other species. This seems to be due to chemoreceptors which can identify conspecifics by their odour.[6] Starfish often converge on food sources and a study was undertaken to examine how they do this. It was found that food-deprived individual Odontaster validus could distinguish between the odours emitted by satiated and by starved starfish of the same species. They were strongly attracted to the former and took little notice of the latter.[6]

Odontaster validus is much less sensitive to higher water temperatures than the other Antarctic marine species on which it feeds which mostly find temperatures above 3 °C lethal. Even when not killed at higher temperatures, many organisms cease to feed, may remain immobile or fail to reproduce and others started metabolising anaerobically.[7] A study was undertaken to examine the implications of this for the Antarctic marine environment if water temperatures rise as a result of global warming.[7]

Another research study examined the parameters required for successful fertilisation of the eggs of Odontaster validus compared to similar temperate water sea stars. It was found that a density of sperm of 105 sperm per millilitre was sufficient to cause a high proportion of eggs to be fertilised and that this was at least ten times the density required by comparable species in less harsh environments. The sperm still retained a minimal fertilisation ability after 24 hours but had a narrow tolerance to variations in water temperature.[8]

References[edit]

  1. ^ a b c Mah, Christopher (2010). "Odontaster validus, Koehler, 1906". World Register of Marine Species. Retrieved 2012-02-15. 
  2. ^ a b c d e f Odontaster validus; Koehler, 1906 Antarctic Field Guide. Retrieved 2011-11-26.
  3. ^ Kidawa, Anna (2005). "Behavioural and metabolic responses of the Antarctic sea star Odontaster validus to food stimuli of different concentration". Polar Biology 28 (6): 449–455. doi:10.1007/s00300-004-0705-2. 
  4. ^ Alexis M. Janosik, Alexis M.; A.R. Mahon; K.H. Halanych (2011). "Evolutionary history of Southern Ocean Odontaster sea star species (Odontasteridae; Asteroidea)". Polar Biology 34 (4): 575–586. doi:10.1007/s00300-010-0916-7. 
  5. ^ a b Pearse, J. S. (1963). The reproductive cycle of the Antarctic asteroid Odontaster validus Koehler. Proceedings of the International Congress of Zoology. p. 111. 
  6. ^ a b Kidawa, Anna (2001). "Antarctic starfish, Odontaster validus , distinguish between fed and starved conspecifics". Polar Biology 24 (6): 408–410. doi:10.1007/s003000100229. Retrieved 2011-11-26. 
  7. ^ a b Peck, Lloyd S, Karen E Webb, Andrew Miller, Melody S Clark, Tim Hill (2008). "Temperature limits to activity, feeding and metabolism in the Antarctic starfish Odontaster validus". Marine Ecology Progress Series 358: 181–189. doi:10.3554/meps07336. Retrieved 2011-11-26. 
  8. ^ Grange, Laura J.; P.A. Tyler; L.S. Peck (2011). "Fertilization success of the circumpolar Antarctic seastar Odontaster validus (Koehler, 1906): a diver-collected study". Proceedings of the American Academy of Underwater Sciences, 30th Scientific Symposium: 140–150. ISBN 978-0-9800423-5-1. 
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!