Air fern | |
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A "potted" air fern | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Cnidaria |
Class: | Hydrozoa |
Order: | Leptothecata |
Family: | Sertulariidae |
Genus: | Sertularia |
Species: | S. argentea |
Binomial name | |
Sertularia argentea | |
Synonyms | |
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The air fern (Sertularia argentea) is a dead and dried colony of hydrozoans, a species of marine animal in the family Sertulariidae related to corals and jellyfish.
Air ferns are typically dyed green and sold as a curiosity, as a decorative "indoor plant"; the same skeletons of former colonies of hydroids are sold in their natural dried state as the sea fir and Neptune plant as underwater decorations for aquariums.
Despite a superficial resemblance to plants, air ferns are actually animal skeletons or shells of marine hydroids of the class Hydrozoa, phylum Cnidaria. The dried colonies are often dyed green, but the coloring will dissolve when soaked in water. Undyed ferns are sometimes labeled as "Neptune plants".
The fernlike branches of S. argentea are composed of many small, chitinous chambers where individual animals once lived. When the colony was alive, a polyp with numerous tentacles occupied each of the chambers, called hydrotheca.
Sometimes dried bryozoa are sold as "air ferns." [1]
Most commercially sold air ferns are collected as a by-product by trawlers in the North Sea.[ citation needed ]
Bryozoa are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about 0.5 millimetres long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869 living species are known. Originally all of the crown group Bryozoa were colonial, but as an adaptation to a mesopsammal life or to deep‐sea habitats, secondarily solitary forms have since evolved. Solitary species has been described in four genera; Aethozooides, Aethozoon, Franzenella and Monobryozoon). The latter having a statocyst‐like organ with a supposed excretory function.
Hydrozoa is a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria.
Stenolaemata are a class of exclusively marine bryozoans. Stenolaemates originated and diversified in the Ordovician, and more than 600 species are still alive today. All extant (living) species are in the order Cyclostomatida, the third-largest order of living bryozoans.
Cheilostomatida, also called Cheilostomata, is an order of Bryozoa in the class Gymnolaemata.
Fragmentation in multicellular or colonial organisms is a form of asexual reproduction or cloning, where an organism is split into fragments upon maturation and the spilted part becomes the new individual.
Bugula is a genus of common colonial arborescent bryozoa, often mistaken for seaweed. It commonly grows upright in bushy colonies of up to 15 cm in height.
Leptothecata, or thecate hydroids, are an order of hydrozoans in the phylum Cnidaria. Their closest living relatives are the athecate hydroids, which are similar enough to have always been considered closely related, and the very apomorphic Siphonophorae, which were placed outside the "Hydroida". Given that there are no firm rules for synonymy for high-ranked taxa, alternative names like Leptomedusa, Thecaphora or Thecata, with or without the ending emended to "-ae", are also often used for Leptothecata.
Conica are a cnidarian suborder of the Leptomedusae. They make up the bulk of their order; their internal relationships are not well resolved, and most of the roughly 30 families are not yet assigned to a superfamily.
Phylactolaemata is a class of the phylum Bryozoa whose members live only in freshwater environments. Like all bryozoans, they filter feed by means of an extensible "crown" of ciliated tentacles called a lophophore, and like nearly all bryozoans, they live in colonies, each of which consists of clones of the founding member. Unlike those of some marine bryozoans, phylactolaemate colonies consist of only one type of zooid, the feeding forms known as autozooids. These are supported by an unmineralized "exoskeleton" made of gelatinous material or protein, secreted by the zooids. The class contains only one extant order, Plumatellida.
Flustra foliacea is a species of bryozoans found in the northern Atlantic Ocean. It is a colonial animal that is frequently mistaken for a seaweed. Colonies begin as encrusting mats, and only produce loose fronds after their first year of growth. They may reach 20 cm (8 in) long, and smell like lemons. Its microscopic structure was examined by Robert Hooke and illustrated in his 1665 work Micrographia.
Eudendrium ramosum, sometimes known as the tree hydroid, is a marine species of cnidaria, a hydroid (Hydrozoa) in the family Eudendriidae of the order Anthoathecata.
Obelia longissima is a colonial species of hydrozoan in the order Leptomedusae. Its hydroid form grows as feathery stems resembling seaweed from a basal stolon. It is found in many temperate and cold seas world-wide but is absent from the tropics.
Solanderia is the sole genus of hydrozoans in the monotypic family Solanderiidae. They are commonly known as tree hydroids or sea fan hydroids.
Hydrocorella africana, the shell-mimic hydroid, is a small colonial encrusting hydroid in the family Hydractiniidae.
Fenestella is a genus of bryozoans or moss animals, forming fan–shaped colonies with a netted appearance. It is known from the Middle Ordovician to the early Upper Triassic (Carnian), reaching its largest diversity during the Carboniferous. Many hundreds of species have been described from marine sediments all over the world.
Schuchertinia milleri, commonly known as the Miller hydractinia, hedgehog hydroid or snail fur, is a small colonial hydroid in the family Hydractiniidae, found in the eastern Pacific Ocean. It forms mat-like colonies on rocks, or sometimes on the mollusc shells occupied by hermit crabs.
Electra posidoniae is a species of bryozoan in the family Electridae. It is endemic to the Mediterranean Sea, and is commonly known as the Neptune-grass bryozoan because it is exclusively found growing on seagrasses, usually on Neptune grass, but occasionally on eelgrass.
Callopora lineata is a species of colonial bryozoan in the family Calloporidae. It is found on rocky shores in the Atlantic Ocean and the Mediterranean Sea.
Chorizopora brongniartii is a species of bryozoan in the family Chorizoporidae. It is an encrusting bryozoan, the colonies forming spreading patches. It has a widespread distribution in tropical and temperate seas.
Lichenalia is an extinct genus of cystoporate bryozoan belonging to the family Rhinoporidae. It is known from the Upper Ordovician to the Middle Silurian periods, which spanned from approximately 460 to 430 million years ago. The genus had a cosmopolitan distribution, with fossil specimens found in various regions of the world, including North America, Europe, and Asia.