Pyrosoma atlanticum

File:Pyrosoma atlanticum (12256).jpg

A colony of P. atlanticum is cylindrical and can grow up to {{cvt|60|cm|ft}} long and {{cvt|4–6|cm|in}} wide. The constituent zooids form a rigid tube, which may be pale pink, yellowish, or bluish. One end of the tube is narrower and is closed, while the other is open and has a strong diaphragm. The outer surface or test is gelatinised and dimpled with backward-pointing, blunt processes. The individual zooids are up to {{cvt|8.5|mm|in}} long and have a broad, rounded branchial sac with gill slits. Along the side of the branchial sac runs the endostyle, which produces mucus filters. Water is moved through the gill slits into the centre of the cylinder by cilia pulsating rhythmically. Plankton and other food particles are caught in mucus filters in the processes as the colony is propelled through the water. P. atlanticum is bioluminescent and can generate a brilliant blue-green light when stimulated.[http://species-identification.org/species.php?species_group=zmns&id=588 Pyrosoma atlanticum] Marine Species Identification Portal. Retrieved 2011-11-11.

P. atlanticum is found in temperate waters in all the world's oceans, usually between 50°N and 50°S. It is most plentiful at depths below 250 m (800 ft).[http://www.sealifebase.org/summary/speciessummary.php?id=55860 Pyrosoma atlanticum - Péron, 1804] SeaLifeBase. Retrieved 2011-11-11. Colonies are pelagic and move through the water column. They undergo a large diurnal migration, rising toward the surface in the evening and descending around dawn. Large colonies may rise through a vertical distance of 760 m (2,500 ft) daily, and even small colonies a few millimetres long can cover vertical distances of 90 m (300 ft).{{cite journal |author1=Andersen, Valérie |author2=Jacques Sardou |name-list-style=amp |year=1994 |title=Pyrosoma atlanticum (Tunicata, Thaliacea): diel migration and vertical distribution as a function of colony size |journal=Journal of Plankton Research |volume=16 |issue=4 |pages=337–349 |doi=10.1093/plankt/16.4.337 }}

A study in the Indian Ocean comparing different zooplankton organisms found that colonies of P. atlanticum were the most efficient grazers of particles above 10 μm in diameter, catching a higher proportion of the particles than other grazers. This implies the species uses high biomass intake as a strategy, rather than investing in energy-conservation mechanisms.{{cite journal |author1=Perissinotto R. |author2=P. Mayzaud |author3=P. D. Nichols |author4=J. P. Labat |title=Grazing by Pyrosoma atlanticum (Tunicata, Thaliacea) in the south Indian Ocean |journal=Marine Ecology |year=2007 |volume=330 |page=1 |doi=10.3354/meps330001 |bibcode=2007MEPS..330....1P |url=https://www.int-res.com/abstracts/meps/v330/feature/ |access-date=2011-11-12|doi-access=free }}

Growth occurs by new rings of zooids being budded off around the edge of the elongating colony. A pair of luminescent organs is on either side of the inlet siphon of each zooid. When stimulated, these turn on and off, causing rhythmic flashing. No neural pathway runs between the zooids, but each responds to the light produced by other individuals, and even by light from other nearby colonies.{{cite journal |author=Bowlby, Mark R. |author2=Edith Widder |author3=James Case |year=1990 |title=Patterns of stimulated bioluminescence in two pyrosomes (Tunicata: Pyrosomatidae) |journal=Biological Bulletin |volume=179 |issue=3 |pages=340–350 |jstor=1542326 |doi=10.2307/1542326 |pmid=29314963 |url=https://www.biodiversitylibrary.org/part/24992 }}

P. atlanticum remains as one of the least studied planktonic grazers, according to a 2021 study. In the study, {{cite journal |last1=Berger |first1=Alexis |last2=Blackwelder |first2=Patricia |last3=Frank |first3=Tamara |last4=Sutton |first4=Tracy T. |last5=Pruzinsky |first5=Nina M. |last6=Slayden |first6=Natalie |last7=Lopes |first7=Jose V. |title=Microscopic and genetic characterization of bacterial symbionts with bioluminescent potential in Pyrosoma atlanticum |journal=Frontiers in Marine Science |date=3 February 2021 |volume=8 |page=606818 |doi=10.3389/fmars.2021.606818 |doi-access=free }} the researchers took samples of the pyrosome's microbiome. The results of the study found that a possible source of bioluminescence in P. atlanticum is the abundance of Photobacterium in its microbiome. However, there is still debate, as a 2020 study found a potential endogenous pyrosome luciferase in the organism's transcriptome homologous to Renilla luciferase (RLuc). Further study of the luciferase showed that it reacted with coelenterazine to produce light, much like RLuc.{{Cite journal|last1=Tessler|first1=Michael|last2=Gaffney|first2=Jean P.|last3=Oliveira|first3=Anderson G.|last4=Guarnaccia|first4=Andrew|last5=Dobi|first5=Krista C.|last6=Gujarati|first6=Nehaben A.|last7=Galbraith|first7=Moira|last8=Mirza|first8=Jeremy D.|last9=Sparks|first9=John S.|last10=Pieribone|first10=Vincent A.|last11=Wood|first11=Robert J.|date=2020-10-20|title=A putative chordate luciferase from a cosmopolitan tunicate indicates convergent bioluminescence evolution across phyla|journal=Scientific Reports |language=en |volume=10 |issue=1 |page=17724 |doi=10.1038/s41598-020-73446-w|pmid=33082360|pmc=7576829|bibcode=2020NatSR..1017724T |doi-access=free}}

Five specimens of the penaeid shrimp Funchalia were found living inside colonies of P. atlanticum. Other amphipods also lived there, including the hyperiids Phronima and Phronimella spp.{{cite journal |author=Lindlay, J. A. |year=2001 |title=Funchalia sp. (Crustacea: Penaeidae) associated with Pyrosoma (Thaliaceae: Pyrosomidae off the Canary Islands |journal=Journal of the Marine Biological Association of the United Kingdom |volume=81 |pages=173–4 |doi=10.1017/s0025315401003551 |s2cid=84501250 |url=http://sabella.mba.ac.uk/501/01/Funchpap.pdf |access-date=2011-11-12 |display-authors=etal |archive-url=https://web.archive.org/web/20120415083902/http://sabella.mba.ac.uk/501/01/Funchpap.pdf |archive-date=2012-04-15 |url-status=dead }}

Predators of P. atlanticum include various bony fishes, such as the spiky oreo, the big-eyed cardinalfish, and the pelagic butterfish, dolphins, and whales such as the sperm whale and giant beaked whale.{{cite journal |last1=Chua |first1=Marcus A.H. |last2=Lane |first2=David J.W. |last3=Ooi |first3=Seng Keat |last4=Tay |first4=Serene H.X. |last5=Kubodera |first5=Tsunemi |title=Diet and mitochondrial DNA haplotype of a sperm whale (Physeter macrocephalus) found dead off Jurong Island, Singapore |journal=PeerJ |date=5 April 2019 |volume=7 |pages=e6705 |doi=10.7717/peerj.6705 |pmid=30984481 |pmc=6452849 |doi-access=free }}{{cite journal |last1=Walker |first1=William A. |last2=Mead |first2=James G. |last3=Brownell |first3=Robert L. |title=Diets of Baird's beaked whales, Berardius bairdii, in the southern Sea of Okhotsk and off the Pacific coast of Honshu, Japan |journal=Marine Mammal Science |date=October 2002 |volume=18 |issue=4 |pages=902–919 |doi=10.1111/j.1748-7692.2002.tb01081.x |url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1098&context=usdeptcommercepub |url-access=subscription }}

File:Pyrosoma elegans 001.png

The following synonyms have been noted:

• Dipleurosoma ellipticum Brooks, 1906 – genus transfer and junior synonym
• Pyrosoma atlanticum dipleurosoma Metcalf & Hopkins, 1919 – junior synonym
• Pyrosoma atlanticum echinatum Metcalf & Hopkins, 1919 – junior synonym
• Pyrosoma atlanticum f. elegans Lesueur, 1815 – junior synonym
• Pyrosoma atlanticum hawaiiense Metcalf & Hopkins, 1919 – junior synonym
• Pyrosoma atlanticum intermedium Metcalf & Hopkins, 1919 – junior synonym
• Pyrosoma atlanticum paradoxum Metcalf & Hopkins, 1919 – junior synonym
• Pyrosoma atlanticum triangulum Neumann, 1913 – junior synonym
• Pyrosoma atlanticum var. giganteum Lesueur, 1815 – junior synonym
• Pyrosoma atlanticum var. levatum Seeliger, 1895 – junior synonym
• Pyrosoma atlanticum var. tuberculosum Seeliger, 1895 – junior synonym
• Pyrosoma benthica Monniot C. & Monniot F., 1966 – junior synonym
• Pyrosoma elegans Lesueur, 1813 – junior synonym
• Pyrosoma ellipticum (Brooks, 1906) – junior synonym
• Pyrosoma giganteum Lesueur, 1815 – junior synonym
• Pyrosoma giganteum var. atlanticum Péron, 1804 – status change
• Pyrosoma rufum Quoy & Gaimard, 1824 – junior synonym
• Pyrosoma triangulum Neumann, 1909 – junior synonym

• Jelly-falls

{{Reflist}}

• {{Commons category-inline|Pyrosoma atlanticum|Pyrosoma atlanticum}}

{{Taxonbar|from=Q4927517}}

Category:Pyrosomatidae

Category:Fauna of the Atlantic Ocean

Category:Fauna of the Indian Ocean

Category:Fauna of the Pacific Ocean

Category:Bioluminescent animals

Category:Animals described in 1804

Category:Taxa named by François Péron

Category:Colonial animals