Asteropseidae Family of Starfish

Two Starfish of the Asteropseidae Family are found in this website:

Phylogeny: The Asteropseidae Sea Stars or Asteropsrid are members of the Asteropseidae Family of Sea Stars. Like Sea Urchins and Sea Cucumbers, belong to the Phylum Echinodermata.  The Echinodermata are of great scientific interest because, via fossil records, they have been dated to the Cambrian Age (over 500,000,000 years ago) with 7,000 living and 13,000 extinct individual species. They are in the class Asteroidae, which means their arms have a broad attachment point where the arms join the disk and taper as they extend from the disk. They are in the order Valvatida, which is characterized by the individuals having the presence of conspicuous marginal ossicles. The Asteropseidae Family is one of fifteen families in this order. The Asteropseidae Family is small with six genera and only one species per genus. Species in the Asteropseidae Family are also known as Asteropseids.

Morphology:  Asteropseids have a wide central disk that is surrounded by five or six wide, tapering arms. The arms are usually shorter than the width of the disk. The arms are sometimes webbed. They have a thick skin on their aboral (dorsal) surface that may give the animal a rubbery, leathery, or velvety texture. The surface may have conical spines and/or pedicellariae. Some species in this family have marginal spines. The disc contains most of the organs, with the mouth on the ventral side and the anus and madreporite (entry plate for the water vascular system) on the dorsal surface. They have a water vascular system, tube feet, and a complete digestive system, but they lack a head, eyes, nervous system, or excretory system. Some feed via inserting the stomach out through the mouth surrounding the prey, secreting enzymes to digest the food and then retracting the stomach when finished eating. Sea Stars in the Asteropseidae Family may be brightly colored. Asteropseids reach a maximum of 30 cm (12 inches) in diameter. 

Distribution:  Asteropseids reside on hard substrates including coral, rock, and man-made objects such as pilings. They are generally found in shallow water, with only a few species reaching depths up to 100 m (328 feet). They are found worldwide in tropical to temperate seas. Three species from the Asteropseidae Family are found in Mexican waters.

Reproduction:  Asteropseid Sea Stars  are gonochoric (male or female for life). They generally reproduce sexually through broadcast spawning, with external fertilization, but some species brood their eggs. The eggs hatch into planktonic larva. The larvae start life in a bilaterally symmetrical form and in adulthood gain their radial symmetry. They are in their larval form for several weeks before beginning their benthic life. They can also reproduce asexually through fragmentation or fission.

Ecosystems Role:  Asteropseids feed by grazing on algae, bryozoans, and sponges, or they may be predators that prey on hydroids, sea cucumbers, sea pens, other sea stars, sea urchins, and tunicates. In turn they are preyed upon by shore birds, crabs, fish, and other sea stars.