View source for Chiropsella bronzie

{{Short description|Species of fish}}
{{Speciesbox
| taxon = Chiropsella bronzie
| authority = [[Lisa-ann Gershwin|Gershwin]], 2006
}}

'''''Chiropsella bronzie''''' is a species of [[box jellyfish]].<ref>{{cite WoRMS |author1=Collins, A.G.|author2= Jarms, G. |year=2021 |title=World List of Cubozoa. ''Chiropsella bronzie'' Gershwin, 2006 |id=390003 |access-date=5 April 2021}}</ref>  It is considered much less of a threat to humans than some of its relatives. The species was described in 2006, and is one of four species in the genus ''Chiropsella''.<ref name=":1" /> ''Chiropsella bronzie'' can be found in shallow waters off the coast of [[Queensland|Queensland, Australia]].<ref name=":1">{{Cite journal|last=Gershwin|first=Lisa-ann|date=2006-06-12|title=Comments on ''Chiropsalmus'' (Cnidaria: Cubozoa: Chirodropida): a preliminary revision of the Chiropsalmidae, with descriptions of two new genera and two new species|url=http://dx.doi.org/10.11646/zootaxa.1231.1.1|journal=Zootaxa|volume=1231|issue=1|pages=1|doi=10.11646/zootaxa.1231.1.1|issn=1175-5334}}</ref>

== Taxonomy ==
''Chiropsella bronzie'' was previously misidentified in 1880 as ''[[Chiropsalmus quadrigatus|Chiropsalmus quadrigata]]'', an Indian Ocean cubozoan of the same order.<ref>{{Cite web|title=WoRMS - World Register of Marine Species - Chiropsalmus quadrigatus Haeckel, 1880|url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=527672|access-date=2021-04-01|website=www.marinespecies.org}}</ref> It was later correctly identified as a new species by Gershwin in 2006.<ref name=":1" /> The species name ''bronzie'' is named after the [[Royal Life Saving Society Australia|Royal Life Saving Society's]] bronze medallion award for a qualified Life Saver.<ref name=":1" />

The order Chirodropida consists of three major families: [[Chirodropidae]], [[Chiropsalmidae]]'','' and [[Chiropsellidae]] containing the [[genera]] ''Meteorona'' and ''Chiropsella.'' Out of all cubozoan relationships, research has shown that the ''Meteorona kishinouyei'' and ''Chiropsella bronzie'' are the closest relatives, as they are the most phylogenically similar.<ref name=":6">{{Cite journal|last1=Toshino|first1=Sho|last2=Miyake|first2=Hiroshi|last3=Shibata|first3=Haruka|date=2015-05-11|title=Meteorona kishinouyei, a new family, genus and species (Cnidaria, Cubozoa, Chirodropida) from Japanese Waters  |journal=ZooKeys|issue=503|pages=1–21|doi=10.3897/zookeys.503.9047|issn=1313-2989|pmc=4440269|pmid=26019668|doi-access=free }}</ref> Both species have similar morphological traits, such as an unbranched gastrovascular cavity saccule, whereas most other cubozoans' gastro cavity saccules are branched.<ref name=":6" /> Some morphological traits used to distinguish the two species are differences in number of tentacles and pedalium shape.

A morphological exception that ''C. bronzie'' holds, compared to other members of the order Chirodropida, is the presence of gastric filaments in its stomach, where other members lack these structures.<ref name=":6" /> Because of this exception, there has been proposals of adjusting Chirodropida taxonomy with the potential addition of another family.

== Description ==

''Chiropsella bronzie'' belongs to the order Chirodropida, which can be distinguished from other box jellyfish by the presence of muscular masses on the medusa's four corners and saccules found in the gastrovascular cavity. The adult bell of the ''Chiropsella bronzie'' is small and rounded, and ranges from 3 to 5&nbsp;cm in diameter,<ref name=":0">{{Cite journal|last1=Garm|first1=A.|last2=O'Connor|first2=M.|last3=Parkefelt|first3=L.|last4=Nilsson|first4=D.-E.|date=2007-10-15|title=Visually guided obstacle avoidance in the box jellyfish Tripedalia cystophora and Chiropsella bronzie|journal=Journal of Experimental Biology|language=en|volume=210|issue=20|pages=3616–3623|doi=10.1242/jeb.004044|pmid=17921163|issn=0022-0949|doi-access=free}}</ref> not exceeding 8&nbsp;cm high and wide.<ref name=":1" /> Each corner of the ''C. bronzie'' medusae holds up to 9 tentacles on each stalk, or pedalium.<ref name=":2">{{Cite journal|last=Bentlage|first=Bastian|date=2013|title=Description of the chirodropid box jellyfish Chiropsella rudloei sp. nov. (Cnidaria: Cubozoa) from Madagascar|url=http://www.journals.cambridge.org/abstract_S1755267213000924|journal=Marine Biodiversity Records|language=en|volume=6|pages=e118|doi=10.1017/S1755267213000924|issn=1755-2672}}</ref><ref name=":1" />

''Chiropsella bronzie'' and other box jellyfish have very developed eyes and sensory structures. Box jellyfish have true eyes, which are found in clusters called [[Rhopalium|rhopalia]]. ''Chiropsella bronzie'' has 24 eyes and 4 morphologically different types on rhopalia, Two of these eyes are camera type eyes, which consist of one upper lens and one lower lens eyes, and two pigment slit eyes. However, similar to ''[[Tripedalia cystophora]]'', ''C. bronzie'' have shown to have weaker eyes than other cubazoa species due to weaker lenses to focus images on the retina.<ref name=":3">{{Cite journal|last1=O’Connor|first1=Megan|last2=Garm|first2=Anders|last3=Nilsson|first3=Dan-E.|date=2009-06-01|title=Structure and optics of the eyes of the box jellyfish Chiropsella bronzie|url=https://doi.org/10.1007/s00359-009-0431-x|journal=Journal of Comparative Physiology A|language=en|volume=195|issue=6|pages=557–569|doi=10.1007/s00359-009-0431-x|pmid=19347342|s2cid=9563849 |issn=1432-1351}}</ref> This is most likely due to eyes being ellipsoid in shape and very soft, unlike the spherical shape of other cubozoa that contain more sensory power.<ref name=":3" /> Research also suggests that ''C. bronzie'' are most likely color blind, a factor that does not inhibit obstacle avoidance.<ref name=":4">{{Cite journal|last=Coates|first=M. M.|date=2003-08-01|title=Visual Ecology and Functional Morphology of Cubozoa (Cnidaria)|journal=Integrative and Comparative Biology|volume=43|issue=4|pages=542–548|doi=10.1093/icb/43.4.542|pmid=21680462|issn=1540-7063|doi-access=free}}</ref><ref name=":0" /> This variation in box jellyfish sensory systems is expected due to the wide range of habitat cubozoa occupy, including sandy beaches, [[mangroves]], kelp forests, the open ocean, and coal reefs.<ref name=":4" /><ref>{{Cite journal|last1=Morandini|first1=André Carrara|last2=Soares|first2=Marcelo de Oliveira|last3=Matthews-Cascon|first3=Helena|last4=Marques|first4=Antonio Carlos|date=2006|title=A survey of the Scyphozoa and Cubozoa (Cnidaria, Medusozoa) from the Ceará coast (NE Brazil)|journal=Biota Neotropica|volume=6|issue=2|doi=10.1590/s1676-06032006000200021|issn=1676-0603|doi-access=free}}</ref> The complexity of box jellyfish eyes allows for more advanced swimming and navigational behavior, such as increased awareness of surroundings and directional swimming.

== Distribution and habitat ==
Cubozoan are distributed globally, but are commonly found in tropical waters in the Indo-Pacific region. ''C. bronzie'' is located in shallow waters near Queensland, Australia,<ref name=":5">{{Cite journal|last1=Gordon|first1=M.|last2=Hatcher|first2=C.|last3=Seymour|first3=J.|date=November 2004 |title=Growth and age determination of the tropical Australian cubozoan Chiropsalmus sp.|url=http://dx.doi.org/10.1007/s10750-004-2655-7|journal=Hydrobiologia|volume=530-531|issue=1–3|pages=339–345|doi=10.1007/s10750-004-2655-7|s2cid=24935723 |issn=0018-8158}}</ref> specifically from [[Cooktown, Queensland|Cooktown]] to [[Townsville]], Australia.<ref name=":2" /> These beach habitats contain mangrove trees, sandy bottoms, and coral reefs. After heavy rainfalls, ''C. bronzie'' habitats include sunken natural debris, such as branches and large rocks, that jellyfish need to navigate.<ref name=":0" />

==Ecology ==
The life cycle of cubozoans can be simplified down to four stages: egg, swimming larvae, sessile [[Polyp (zoology)|polyps]], and swimming [[Jellyfish|medusae]]. Body plans are reorganized between each stage during metamorphosis, with the exception of development from egg to larvae. In the final metamorphosis, box jellyfish develop complex nervous systems, including advanced visual organs.<ref name=":7">{{Cite journal|last1=Gurska|first1=Daniela|last2=Garm|first2=Anders|date=2014-07-21|title=Cell Proliferation in Cubozoan Jellyfish Tripedalia cystophora and Alatina moseri|journal=PLOS ONE|language=en|volume=9|issue=7|pages=e102628|doi=10.1371/journal.pone.0102628|issn=1932-6203|pmc=4105575|pmid=25047715|bibcode=2014PLoSO...9j2628G |doi-access=free }}</ref> The rhopalia nervous system (RNS) is also developed during the final body reorganization.<ref name=":7" />

Box jellyfish can exhibit both asexual and sexual reproduction. Sexual reproduction occurs during the medusa stage, where the adult male jellyfish releases sperm into the water, and the female releases eggs to be fertilized. In some cases, the male medusa can directly inseminate the female using a sperm packet. In this case, the eggs will develop inside the bell as opposed to the open water.<ref>{{Cite journal|date= August 2015 |title=Stinging cells help jellyfish to mate|journal=Nature|language=en|volume=524|issue=7566|pages=390|doi=10.1038/524390c|issn=1476-4687|doi-access=free}}</ref> Fertilized eggs then develop into a jellyfish larvae stage called a [[planula]]. These larvae contain cilia that allow them to swim throughout the water column. Box jellyfish remain in the planula larvae phase until settling on a hard surface on the seafloor where they will develop into a polyp.

Box jellyfish can also reproduce by means of asexual reproduction through [[budding]], where settled jellyfish polyps can create small cloned "buds" on their body stalks. Once a bud is fully formed, it will break off of the polyp and develop into a medusae. Another difference between true jellyfish ([[scyphozoa]]ns) and cubozoans is that the entire cubozoan polyp develops into a medusae, as opposed to going through [[strobilation]].<ref>{{Cite web|last=says|first=Hatty Shi|date=2017-03-13|title=How Do Box Jellyfish Reproduce {{!}} Box Jellyfish Life Cycle & Reproduction -|url=https://boxjellyfish.org/how-do-box-jellyfish-reproduce-box-jellyfish-life-cycle/|access-date=2021-04-01|website=Box Jellyfish|language=en-US}}</ref> The habitat of ''Chiropsella bronzie'' polyps is still unknown, but research suggests they settle near or on beaches and mangroves.<ref name=":5" /> In addition, it is unknown how long ''C. bronzie'' remains in the polyp stage before maturing to their final medusa stage. Once reaching the final stage, adult box jellyfish will spawn and begin the reproductive cycle again. Cubozoans have shown to have short life spans of two years of less.

== Behavior ==
Box jellyfish tend to move much faster than other jellyfish, with ''Chiropsella bronzie'' having a maximum speed of 7–8&nbsp;cm per second against a 1&nbsp;cm per second current.<ref name=":0" /> Unlike true jellyfish who tend to simply float along with currents, cubozoans are known to be effective predators that hunt using their complex eyes. Their prey consists of mostly shrimp, specifically ''Acestes australis''.<ref name=":0" />

== Sting and toxicity ==
The venom contained in ''C. bronzie’s'' [[cnidocyte]]s is much less potent than other cubozoans, as there has been no evidence that ''C. bronzie'' can deliver a lethal sting to a human.<ref name=":1" /> However, studies have shown that the venom of ''C. bronzie'' has adversely affected the cardiovascular system of anesthetized rats in laboratory settings by greatly lowering their heart rate.<ref>{{Cite journal|last1=Winter|first1=Kelly L.|last2=Fernando|first2=Ross|last3=Ramasamy|first3=Sharmaine|last4=Seymour|first4=Jamie E.|last5=Isbister|first5=Geoffrey K.|last6=Hodgson|first6=Wayne C.|date=2007-01-10|title=The in vitro vascular effects of two chirodropid (Chironex fleckeri and Chiropsella bronzie) venoms|url=https://www.sciencedirect.com/science/article/pii/S0378427406013002|journal=Toxicology Letters|language=en|volume=168|issue=1|pages=13–20|doi=10.1016/j.toxlet.2006.10.011|pmid=17141433|issn=0378-4274}}</ref> The venom of ''C. bronzie'' may be very similar to that of ''[[Chironex fleckeri]]'', but potentially less potent. This could be confirmed by the fact ''C. bronzie'' are more abundant than ''C. fleckeri'', but have no history to be the cause of human fatalities.<ref name=":5" /> A stronger venom would also allow ''C. bronzie'' to feed on fish, while their diet is limited to smaller prey, like shrimp. More research is needed to increase understanding of just how harmful the venom of ''C. broznie'' can be to humans.

== References ==
{{Reflist}}

{{Taxonbar|from=Q3998507}}

[[Category:Chiropsellidae]]
[[Category:Cnidarians of the Pacific Ocean]]