? Sea Pens
Pennatula aculeata
Scientific classification
Kingdom: Animalia Phylum: Cnidaria Class: Anthozoa Subclass: Alcyonaria (Octocorallia) Order: Pennatulacea Verrill, 1865
Families
Suborder Sessiliflorae Anthoptilidae Chunellidae Echinoptilidae Funiculinidae Kophobelemnidae Protoptilidae Renillidae Scleroptilidae Stachyptilidae Umbellulidae Veretillidae Suborder Subselliflorae Pennatulidae Pteroeididae Virgulariidae

Sea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 14 families within the order; they are thought to have a cosmopolitan distribution in tropical and temperate waters worldwide. Sea Pens are grouped with the octocorals ("soft corals"), together with Sea Whips and Sea Feathers. Overhead view of a sea pen (Pennatula aculeata) from USGS. Photo by Dann Blackwood and Page Valentine. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa {trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (flatworms, echinoderms, etc. ... Classes Anthozoa - Corals and sea anemones Cubozoa - Sea wasps or box jellyfish Hydrozoa - Hydroids, hydra-like animals Scyphozoa - Jellyfish Cnidaria (from New Latin cnida nematocyst, fr. ... Orders Subclass Alcyonaria (Octocorallia)   Alcyonacea - Soft corals   Gorgonacea - sea fan,sea feather   Helioporacea   Pennatulacea - sea pen, sea pansy   Stolonifera   Telestacea Subclass Ceriantipatharia   Antipatharia - black coral, thorny coral   Ceriantharia - tube-dwelling anemone Subclass Hexacorallia   Actiniaria - Sea anemone   Scleractinia - stony coral Subclass Zoantharia   Corallimorpharia   Ptychodactiaria   Rugosa†   Zoanthidea - zoanthid Anthozoa is a class... Addison Emery Verrill (1839 - 1926) was an American zoologist. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Classes Anthozoa - Corals and sea anemones Cubozoa - Sea wasps or box jellyfish Hydrozoa - Hydroids, hydra-like animals Scyphozoa - Jellyfish Cnidaria (from New Latin cnida nematocyst, fr. ... Orders Scleractinia Corals are gastrovascular marine cnidarians (phylum Cnidaria; class Anthozoa) existing as small sea anemone-like polyps, typically forming colonies of many individuals. ...

Although named after their feather-like appearance redolent of antique fountain pens, only Sea Pen species belonging to the suborder Subselliflorae live up to the comparison. Those belonging to the much larger suborder Sessiliflorae lack feathery structures and grow in club-like or radiating forms. The latter suborder includes what are commonly known as Sea Pansies. A fountain pen is a writing instrument, more specifically a pen, that contains a reservoir of water-based ink that is fed to a nib through a feed via a combination of gravity and capillary action. ...

As octocorals, Sea Pens are composed of many tiny individual animals called polyps (somewhat like miniature sea anemones), each with eight tentacles. Unlike other octocorals, however, a Sea Pen's polyps are specialized to specific functions: a single polyp develops into a rigid, erect stalk (the rachis) and loses its tentacles, forming a bulbous "root" or peduncle at its base. Other polyps branch out from this central stalk, forming water intake structures (siphonozooids), feeding structures (autozooids) with nematocysts, and reproductive structures. The entire colony is fortified by calcium carbonate in the form of spicules and a central axial rod. In zoology, a polyp is one of two forms of individuals found in many species of cnidarians. ... Families Many, see text. ... Tentacles can refer to the elongated flexible organs that are present in many invertebrates, and sometimes to the hairs of the leaves of some insectivorous plants. ... In zoology, a polyp is one of two forms of individuals found in many species of cnidarians. ... Cnidocytes are prey-capture and defensive cells found on animals of the phylum Cnidaria. ...

Uprooted Sea Pen with the bulbous peduncle in view.

Using their root-like peduncles to anchor themselves in sandy or muddy substrate, the exposed portion of sea pens may rise up to 2 metres in some species, such as the Tall Sea Pen (Funiculina quadrangularis). Sea Pens are sometimes brightly coloured; the Orange Sea Pen (Ptilosarcus gurneyi) is a notable example. Rarely found above depths of 10 metres, Sea Pens prefer deeper waters where turbulence is less likely to uproot them. Some species may inhabit depths of 2,000 metres or more. Download high resolution version (573x604, 28 KB)An unidentified species of sea pen with the bulbous peduncle in view. ... Download high resolution version (573x604, 28 KB)An unidentified species of sea pen with the bulbous peduncle in view. ...

While generally sessile animals, Sea Pens are able to relocate and re-anchor themselves if need be. They position themselves favourably in the path of currents, ensuring a steady flow of plankton, the Sea Pens' chief source of food. Their primary predators are nudibranchs and starfishs, some of which feed exclusively on Sea Pens. When touched, Sea Pens emit a bright greenish light; this is known as bioluminescence. They may also force water out of themselves as a defensive act, deflating and retreating into their peduncle. Photomontage of plankton organisms Plankton are drifting organisms that inhabit the water column of oceans, seas, and bodies of fresh water. ... Infraorders See text Nudibranchs (Nudibranchia), form the largest suborder of the order Opisthobranchia, subclass Orthogastropoda, class Gastropoda in the phylum Mollusca. ... NON TECHNICAL AND OF LOW INTELLIGENCE COMPUTER USER CALLING TECH SUPPORT. SEE S.E.C.S. ALSO This page is a candidate for speedy deletion. ... Bioluminescence is the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy. ...

Like other anthozoans, Sea Pens reproduce by co-ordinating a release of sperm and eggs into the water column; this may occur seasonally or throughout the year. Fertilized eggs develop into larvae called planulae which drift freely for about a week before settling on the substrate. Mature Sea Pens provide shelter for other animals, such as juvenile fish. Analysis of rachis growth rings indicates Sea Pens may live for 100 years or more, if the rings are indeed annual in nature. Orders Subclass Alcyonaria (Octocorallia)   Alcyonacea - Soft corals   Gorgonacea - sea fan,sea feather   Helioporacea   Pennatulacea - sea pen, sea pansy   Stolonifera   Telestacea Subclass Ceriantipatharia   Antipatharia - black coral, thorny coral   Ceriantharia - tube-dwelling anemone Subclass Hexacorallia   Actiniaria - Sea anemone   Scleractinia - stony coral Subclass Zoantharia   Corallimorpharia   Ptychodactiaria   Rugosa†   Zoanthidea - zoanthid Anthozoa is a class... Groups Conodonta Hyperoartia Petromyzontidae (lampreys) Pteraspidomorphi (early jawless fish) Thelodonti Anaspida Cephalaspidomorphi (early jawless fish) Galeaspida Pituriaspida Osteostraci Gnathostomata (jawed vertebrates) Placodermi Chondrichthyes (cartilaginous fish) Acanthodii Osteichthyes (bony fish) Actinopterygii (ray-finned fish) Sarcopterygii (lobe-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) A fish is a poikilothermic (cold-blooded) water-dwelling...

The Sea Pen fossil record is patchy and disputed by some; while the earliest accepted fossils are known from the Cambrian-aged Burgess Shale, similar fossils from the late Proterozoic (Vendian) may represent the dawn of Sea Pens. Precisely what the Proterozoic fossils are, however, is not decided. A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ... The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon and ended about 490 million years BP with the beginning of the Ordovician period. ... The Burgess shale (named after Mount Burgess, near where the shale was found) is a black shale found high up in the Canadian Rockies in Yoho National Park near the town of Field, British Columbia. ... In geology, the Proterozoic is an eon prior to the first abundant complex life on earth. ... The Vendian biota (also known as Vendian forms, Vendian fauna(s), and Vendazoa) are a group of ancient lifeforms that are found in rocks a bit older than the Cambrian faunas that represent the oldest fossils of classical paleontology. ...