sea pen


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sea pen,

long, slender colonial organism of the same phylum as the jellyfish. Sea pen colonies are formed by several genera of the order Pennatulacea. The colony consists of a stalk formed by an organism called a primary polyp (see polyp and medusapolyp and medusa,
names for the two body forms, one nonmotile and one typically free swimming, found in the aquatic invertebrate phylum Cnidaria (the coelenterates). Some animals of this group are always polyps, some are always medusae, and some exhibit both a polyp and a medusa
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) and short branches formed by secondary polyps. The stalk, embedded in sand or mud, holds the colony upright. Sea pens differ from the closely related sea pansiessea pansy,
fleshy, leaf-shaped colony of marine organisms belonging to the genus Renilla in the same phylum as the jellyfish. The colony consists of a stalk formed by a large organism called a primary polyp (see polyp and medusa) that is thrust into soft bottom material;
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 and sea feathers by the form of the colony. Sea pens are marine organisms; they are found on Atlantic and Pacific coasts in shallow to moderately deep water. Some reach a length of 2 ft (61 cm) or more. They belong in the phylum CnidariaCnidaria
or Coelenterata
, phylum of invertebrate animals comprising the sea anemones, corals, jellyfish, and hydroids. Cnidarians are radially symmetrical (see symmetry, biological).
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, class Anthozoa, order Pennatulacea.

sea pen

[′sē ‚pen]
(invertebrate zoology)
The common name for cnidarians constituting the order Pennatulacea.
References in periodicals archive ?
Sea whips and orange sea pens were more abundant at the northern sites (Table 2, blocking variable P<0.
Our observations of bite-strikes on the sea pen Ptilosarcus gurneyi are similar to reports of feeding on Virgularia sp.
White-plumed anemones were most dense in mud-gravel habitats, and sea pens were most dense in low-relief mixed-sediments (Fig.
The sea pen will be 250 feet long, 100 feet wide and 24 feet deep or more, depending on the actual depth of the bay or fiord that's selected.
So far we've built the sea pen and we have a base camp in the national park, Karimunjawa National Park, and we were in the process of confiscating the first three dolphins--two spinner dolphins and a bottlenose dolphin--and 30 minutes before the confiscation, somebody pulled the rug from under us and everything came to a stop.
From there, a military helicopter waited to chauffeur the dolphins to a natural sea pen on the coast of Nicaragua's Corn Island, where marine mammal specialist Ric O'Barry began their rehabilitation.
In Canada she was put in another sea pen and released when her original pod swam by.
The RSPCA said sea pens can provide a more natural environment for captive dolphins but the process needs careful consideration, substantial planning and will also require substantial financial support.
Mud is ideal for delicate blonde and red sea pens and burrowing animals like langoustine and ocean quahog.
Sea floors that have not been dredged or trawled tend to be covered with a dense reef of living creatures: oysters, fan mussels and many other shelly species, soft corals, sea pens, sea fans, sponges, coralline seaweeds, peacock worms and anenomes.
The most commonly used grow-out systems for sea cucumbers are earthen ponds, sea pens, sea cages, and release into delimited areas of seabed (i.
Until now, scientists had long believed the rocks were made up of ocean sediments and that Dickinsonia and other primeval creatures fossilized in the outcroppings were sea dwellers similar to jellyfish or sea pens that lived just before the Cambrian explosion began about 540 million years ago, when all the major animal groups suddenly appeared.