Swima
Encyclopedia
Swima is a genus
of polychaete
worm
that lives in the deep ocean. This deep ocean
pelagic
(free-swimming) annelid
has modified bioluminescent
gill
s that can be cast off from an individual. These discarded gills somewhat resemble green "bombs" that remain illuminated for several seconds after they have been discarded. It is thought that this is a defensive mechanism rather than reproductive, as it is seen in both mature and juvenile individuals. Animals of the Swima genus are closely related to the recently discovered Teuthidodrilus
genus, another pelagic cirratuliform of the bathyal zone
.
of Monterey Bay
, off the coast of California
.
, S. bombiviridis has been formally named.
s, a single medial subulate branchia
, and four pair of small segmental branchiae modified as elliptical, bioluminescent sacs.
, referring to the animal's ability to swim. The species name, bombiviridis, is derived from the Latin prefix bombus, meaning humming or buzzing (from which the English word bomb is derived), and the suffix viridis, which is Latin for the color green. Swima bombiviridis therefore translates to "swimming green bomber".
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of polychaete
Polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...
worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
that lives in the deep ocean. This deep ocean
Bathyal zone
The bathyal zone or bathypelagic – from Greek βαθύς , deep – is that part of the pelagic zone that extends from a depth of 1000 to 4000 metres below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The average temperature hovers at about 39°F...
pelagic
Pelagic fish
Pelagic fish live near the surface or in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or the lake. They can be contrasted with demersal fish, which do live on or near the bottom, and reef fish which are associated with coral reefs.The marine pelagic...
(free-swimming) annelid
Annelid
The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...
has modified bioluminescent
Bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...
gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s that can be cast off from an individual. These discarded gills somewhat resemble green "bombs" that remain illuminated for several seconds after they have been discarded. It is thought that this is a defensive mechanism rather than reproductive, as it is seen in both mature and juvenile individuals. Animals of the Swima genus are closely related to the recently discovered Teuthidodrilus
Teuthidodrilus
Teuthidodrilus , is a genus of marine polychaete worms discovered by marine biologists from the Scripps Institution of Oceanography in November 2010...
genus, another pelagic cirratuliform of the bathyal zone
Bathyal zone
The bathyal zone or bathypelagic – from Greek βαθύς , deep – is that part of the pelagic zone that extends from a depth of 1000 to 4000 metres below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The average temperature hovers at about 39°F...
.
Discovery
The first specimens of the Swima genus were discovered in the deep trenchesOceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor....
of Monterey Bay
Monterey Bay
Monterey Bay is a bay of the Pacific Ocean, along the central coast of California. The bay is south of San Francisco and San Jose, between the cities of Santa Cruz and Monterey....
, off the coast of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
Taxonomy
There are currently three species recognised within the Swima genus, of which only the type speciesType species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
, S. bombiviridis has been formally named.
- S. bombiviridis (also known as Green Bomber Worm or Bombardier Worm) Osborn et al., 2009, from Monterey BayMonterey BayMonterey Bay is a bay of the Pacific Ocean, along the central coast of California. The bay is south of San Francisco and San Jose, between the cities of Santa Cruz and Monterey....
, CaliforniaCaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area... - S. sp. 1, Shining Bomber
- S. sp. 2, Tawi-Tawi Bomber
Anatomy and physiology
Animals of the Swima genus are characterized by a thick gelatinous sheath, transparent body, simple nuchal organNuchal organ
The nuchal organ is a ciliated pit or groove present at the posterior end of the prostomium of annelid worms, some cephalopods, and other invertebrates....
s, a single medial subulate branchia
Branchia
Branchia may refer to:* Branchia, an Ancient Greek word for gills.* Branchia , a genus of arthropods....
, and four pair of small segmental branchiae modified as elliptical, bioluminescent sacs.
Etymology
The genus name, Swima, is derived from the LatinLatin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, referring to the animal's ability to swim. The species name, bombiviridis, is derived from the Latin prefix bombus, meaning humming or buzzing (from which the English word bomb is derived), and the suffix viridis, which is Latin for the color green. Swima bombiviridis therefore translates to "swimming green bomber".