Latest Echinoderm Stories
Scientists reorganise the animal phylogenetic tree An international team of scientists including Albert Poustka from the Max Planck Institute for Molecular Genetics in Berlin has discovered that Xenoturbellida and the acoelomorph worms, both simple marine worms, are more closely related to complex organisms like humans and sea urchins than was previously assumed. As a result they have made a major revision to the phylogenetic history of animals. Up to now, the acoelomate worms were viewed as...
Two groups of lowly marine worms are related to complex species including vertebrates (such as humans) and starfish, according to new research. Previously thought to be an evolutionary link between simple animals such as jellyfish and the rest of animal life - the worms' surprising promotion implies that they have not always been as simple as they now appear.Although the marine worms Xenoturbella and Acoelomorpha are very simple animals "“ they lack a developed nervous system or gut "“...
The impact on levels of carbon dioxide in the Earth's atmosphere by the decaying remains of a group of marine creatures that includes starfish and sea urchin has been significantly underestimated."Climate models must take this carbon sink into account," says Mario Lebrato, lead author of the study. The work was done when he was at the National Oceanography Centre, Southampton (NOCS) and affiliated with the University of Southampton's School of Ocean and Earth Science (SOES); he is...
By Alvarado, Juan Jose Abstract: Between October 2003 and July 2005, aggregation behavior of the sea urchin Astropyga pulvinta Lamarck was studied in Bahia Culebra, Costa Rica. This sea urchin forms aggregations during part of the year and then disappears. I quantified the number of individuals present in a defined area each month, their aggregation behavior between day and night, and their size. Also, temperature and nutrient concentrations of the water were sampled. There were...
By Crawford, Terry J Crawford, Bruce J Abstract: In Rarotonga, Linckia multifora (Lamarck) exists in two forms: a blue gray type that is found on the reef intertidally and a red form that is found subtidally. Both types reproduce asexually by regeneration of autotomized arms, as well as sexually, but the relative potential for sexual reproduction varies greatly between these different sites. In the laboratory, reciprocal crosses of the blue gray intertidal form and the red subtidal form...
Genetic analysis of an obscure, worm-like creature retrieved from the depths of the North Atlantic has led to the discovery of a new phylum, a rare event in an era when most organisms have already been grouped into major evolutionary categories. The analysis also appears to shed light on the ancestor of chordates, the backboned animals that include human beings and two small invertebrate groups closely related to one another: lancelets and tunicates.Its a tremendous surprise that this...
Latest Echinoderm Reference Libraries
The Mediterranean feather star is a filter feeder that obtains food by straining suspended matter and food particles from water. The star has a stalk that has up to forty tendrils, (threadlike organs) which help the star cling to hard surfaces. The “body” of the star is called a calyx and is shaped like a small cup. This calyx is surrounded by feathery pinnules bearing arms. These arms are quite unique in the fact that they can regenerate if one should get broken off; these arms extend to...
The Rosy feather star is a species of starfish in the Antedonidae family. It is found in North West Europe along the coast. The specific area of the coast is between the Shetland Islands south to Portugal. There have been sightings in Algeria, Tunisia, West Africa and Venezuela. The Western and Eastern coasts of the British Isles has a climate that promotes the growth of the Antedon bifida. It grows between the low tide mark and 650 feet deeper. Clinging to rocks, seaweed and mollusks, it...
The European Spider Crab (Maja squinado), also known as the Spiny Spider Crab, is a species of migratory crab found in the north-east Atlantic and the Mediterranean Sea. This species migrates usually in autumn, an some crabs may cover more than 100 miles in eight months. It feeds on a great variety of organisms, with seaweeds and mollusks dominating in winter, and echinoderms such as sea urchins and sea cucumbers in summer. Females can produce up to 4 broods per year. This species is the...
