// Workers AI · dad joke modeWhat did the Pterasteridae say? "We're star-struck.

Pterasteridae Temporal range:
Pteraster capensis
Scientific classification
Kingdom:	Animalia
Phylum:	Echinodermata
Class:	Asteroidea
Order:	Velatida
Family:	Pterasteridae Perrier, 1875
Genera
See text

Pterasteridae is a family of sea stars in the order Velatida, consisting of eight genera.

Description and characteristics

Pterasterids are primarily deep-water, and have an inflated aboral surface. Like many other members of the ordo Velatida, they have a hole in the middle of the central disc called "osculum", from which they can expel mucus for defending against predators.

Many species brood their young in an internal chamber flushed with seawater.

Fossil pterasterids have been found as early as the upper Campanian of the Cretaceous period.

Genera

According to the World Register of Marine Species :

• Amembranaster Golotsvan, 1998 -- 1 species
• Benthaster Sladen, 1882 -- 3 species
• Calyptraster Sladen, 1882 -- 5 species
• Diplopteraster Verrill, 1880 -- 7 species
• Euretaster Fisher, 1940 -- 3 species
• Hymenaster Thomson, 1873 -- 51 species
• Hymenasterides Fisher, 1911 -- 2 species
• Pteraster Müller & Troschel, 1842 -- 46 species

• 
  Euretaster insignis
• 
  Hymenaster echinulatus (both faces)
• 
  Hymenaster sp.
• 
  Pteraster stellifer (both faces)
• 
  Pteraster sp.

External links

• Data related to Pterasteridae at Wikispecies
• Media related to Pterasteridae at Wikimedia Commons