
''Sabellastarte spectabilis'' is a
species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...
of
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...
marine
polychaete
Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ...
worm in the
Sabellidae
Sabellidae, or feather duster worms, are a family of marine polychaete tube worms characterized by protruding feathery branchiae. Sabellids build tubes out of a tough, parchment-like exudate, strengthened with sand and bits of shell. Unlike t ...
family. It is commonly known as the feather duster worm, feather duster or fan worm.
[Introduced marine species of Hawaii]
/ref> It is native to tropical waters of the Indo-Pacific but has spread to other parts of the world. It is popular in aquariums because of its distinctive appearance and its ability to remove organic particles and improve water quality.
Polychaetes, or marine bristle worms, have elongated bodies divided into many segments. Each segment may bear setae
In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms.
Animal setae
Protostomes
Annelid setae are stiff bristles present on the body. ...
(bristles) and parapodia
In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; plural: parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in annelids, where they are paired, unjointed ...
(paddle-like appendages). Some species live freely, either swimming, crawling or burrowing, and these are known as "errant". Others live permanently in tubes, either calcareous or parchment-like, and these are known as "sedentary".
Taxonomy
This worm has a complex taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. A ...
history. It was known as ''Sabellastarte sanctijosephi'' when it first appeared in Hawaii in the 20th century.[ The names ''S. punctata'' and ''S. indica'' were used by Hartman (1966) and others. In 2003 Knight-Jones and Mackie undertook a revision of the genus ''Sabellastarte'' and determined that ''Sabellastarte spectabilis'' was the correct name.
]
Description
This large worm can reach millimetres in length and in width. It is buff in colour with purple specks. It lives in a tough, leathery tube covered with fine mud. Projecting from this is a branchial crown of branched tentacle
In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...
s, the radiole
A radiole is a heavily ciliated feather-like tentacle found in highly organized clusters on the crowns of Canalipalpata. Canalipalpata is an order of sessile marine polychaete worms consisting of 31 families (including the Sabellidae, Serpulidae, ...
s, which form a plume. The tentacles are striped in dark and pale brown bands and bear neither stylodes nor eye spots. There are two long, slender palps and a four-lobed collar.
Distribution
The native range of ''S. spectabilis'' is the Indian Ocean and the Red Sea
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...
, but it is now also found on the coasts of Africa and Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Mala ...
and the Gulf of Mexico
The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United S ...
. In 2002 it was reported on pilings, floating docks and harbour walls in Hawaii.USGS
/ref>
Habitat
''S. spectabilis'' is found in holes and cracks and among algae
Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from ...
on reef
A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic processes—deposition (geology), deposition of ...
s and rocky shores. It is sometimes found growing in crevices in the coral ''Pocillopora meandrina
''Pocillopora meandrina'', commonly known as cauliflower coral, is a species of coral occurring in the Indo-Pacific and Pacific oceans. This coral lives in shallow reef environments.
Description
The colonies of ''P. meandrina'' can be fairly sol ...
'', under boulders in still water, in holes in lava, in tidal pools and in channels exposed to heavy surf.
Biology
''S. spectabilis'' is a filter feeder
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...
. Cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
on the tentacles cause currents in the water and organic
Organic may refer to:
* Organic, of or relating to an organism, a living entity
* Organic, of or relating to an anatomical organ
Chemistry
* Organic matter, matter that has come from a once-living organism, is capable of decay or is the product o ...
particles are caught as they float past. They are channelled along mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...
-filled grooves to the mouth. Larger non-food particles are used for building the tube. The tentacles are also used as gills for gas exchange.
This worm can reproduce asexually
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the fu ...
by fragmentation
Fragmentation or fragmented may refer to:
Computers
* Fragmentation (computing), a phenomenon of computer storage
* File system fragmentation, the tendency of a file system to lay out the contents of files non-continuously
* Fragmented distributi ...
, and can regenerate body parts after being damaged. Reproduction can also be by sexual means. Most worms are either male or female and the gamete
A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce ...
s mature in the coelom
The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, it ...
before being released into the water column
A water column is a conceptual column of water from the surface of a sea, river or lake to the bottom sediment.Munson, B.H., Axler, R., Hagley C., Host G., Merrick G., Richards C. (2004).Glossary. ''Water on the Web''. University of Minnesota-D ...
. Some specimens, particularly larger ones, have both male and female gametes and a study concluded that this was consistent with sequential hermaphroditism
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many taxonomic groups of animals (mostly invertebrates) do not have se ...
. Fertilization is external, and after a short time in the plankton
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cr ...
, the trochophore
A trochophore (; also spelled trocophore) is a type of free-swimming planktonic marine larva with several bands of cilia.
By moving their cilia rapidly, they make a water eddy, to control their movement, and to bring their food closer, to captur ...
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
Th ...
e settle out and grow into adult worms.
References
{{Taxonbar, from=Q2574613
Sabellida
Fauna of the Indian Ocean
Animals described in 1878
Taxa named by Adolph Eduard Grube