''Spiculosiphon oceana'' is a giant species of

foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and ot ...

(a phylum of unicellular

eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

s). Its appearance and lifestyle mimics that of a

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

. It was discovered in 2013 in underwater caves 30 miles off the coast of Spain.

Description

At () long, ''Spiculosiphon oceana'' is the largest

found in the Mediterranean. The species creates a test (shell) made out of

sponge spicules Spicules are structural elements found in most sponges. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators. Sponge spicules are made of calcium carbon ...

, "gluing" them together with a protein it secretes, much like sponges do. The spicules it uses are carefully selected and laid parallel to the main stalk of the creature. Because of its large size and its appearance, ''S. oceana'' was originally mistaken as a multi-cellular animal from the sponge family. ''Spiculosiphon oceana'' lives on the sea floor. It lies in wait and extends its

pseudopod A pseudopod or pseudopodium (plural: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that is emerged in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filamen ...

s outside its shell to capture prey, primarily

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

, that get trapped on the spicules of its shell. Thus, it captures prey much in the same way as carnivorous sponges. In addition to the visual and lifestyle similarities of ''S. oceana'' and sponges, the creatures live in similar habitats. Thus, it is likely a case on convergent evolution dictated by the environmental constraints. In May 2014, The

International Institute for Species Exploration The International Institute for Species Exploration (IISE) is a research institute located in Syracuse, New York. Its mission is to improve taxonomical exploration and the cataloging of new species of flora and fauna. Since 2008, IISE has publ ...

selected ''S. oceana'' as one of the Top 10 New Species of the previous year.

Discovery and taxonomic history

''Spiculosiphon oceana'' was on the Seco de Palos

seamount A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...

, southeast of Spain. It was formally described in the June 10, 2013 issue of ''

Zootaxa ''Zootaxa'' is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press (Auckland, New Zealand). The journal was established by Zhi-Qiang Zhang in 2001 and new issues are published multiple times a week. ...

''. The specific name is a reference to the non-profit group Oceana who co-discovered the species with Centro de Estudios Avanzados de Blanes (CEAB-CSIC). ''Spiculosiphon oceana'' is the second species of '' Spiculosiphon'', the first being '' Spiculosiphon radiata''. ''S. oceana'' is roughly twice the size of its sister species, which was found in Norway.

References

{{Taxonbar, from=Q16918627 Monothalamea Biota of the Mediterranean Sea Protists described in 2013