Annual gonadal variation in sea urchins of the orders Echinothurioida and Echinoida
Molecular phylogenies and divergence times of sea urchin species of Strongylocentrotidae, Echinoida
Agassiz, 1863) Genero Centrostephanus Peters, 1855 Centrostephanus coronatus (verrill, 1867) Orden Echinoida
Claus, 1876 Familia Echinometridae Gray, 1825 Genero Echinometra Gray, 1825 Echinometra vanbrunti (A.
Superorder Echinacea Order Echinoida
Family Echinidae Genus Psammechinus AGASSIZ y DESOR, 1846 Psammechinus affinis FUCHS P1.
Even more strikingly, crosses between sea urchin species in the order Temnopleurida and the order Echinoida
(Brandhorst and Davenport, 2001) unite lineages that have been separate for only about 40 million years (Smith, 1988).
In two other large orders, Echinoida
and Diadematoida, respectively, 69% of 65 species and 54% of 48 species were sampled.
Molecular phytogenies and divergence times of sea urchin species of Strongylocentrotidae, Echinoida
We polarized the ancestral character state in the Echinoida
by placing Holothuria atra (Holothuridae) as an outgroup.
Bilaterally symmetrical feeding larvae occur in four classes--Asteroida, Ophiuroida, Holothuroida, and Echinoida.
The early larval stages of this species have been described previously (Mortensen, 1931; Shetty, 1960) and were said to resemble larvae of the family Echinometridae (order Echinoida, superorder Camerodonta).
The five genera in which bindin was previously sequenced belong to two echinoid orders, the Echinoida
and the Arbacioida.
Of these, eight involve brood-protection (Cidaroida, Temnopleuroida, Echinoida
, Spatangoida [including Schizasteridae and Brissidae], Holasteroida, Cassiduloida, Clypeasteroida).