Final Article Submission edit

Compass jellyfish
 
Scientific classification  
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Scyphozoa
Order: Semaeostomeae
Family: Pelagiidae
Genus: Chrysaora
Species:
C. hysoscella
Binomial name
Chrysaora hysoscella
(Linnaeus, 1766)

Chrysaora hysoscella, commonly known as the compass jellyfish, is a very common species of jellyfish that inhabits the coastal waters in cold and temperate regions of the Atlantic Ocean[1]. It is a 'true' jellyfish displaying radial symmetry with distinct brown markings shaped like elongated V's on its bell[1]. C. hysoscella adults are highly susceptible to the parasite Hyperia medusarum but this hasn't had any significant effects on the population.[2] This organism has a benthic polyp stage before developing into a pelagic adult medusae.[1] Compass jellyfish consume a variety of marine invertebrates and plankton and are preyed on by very few.[3] C. hysoscella contribute to the global issue of jellyfish overpopulation which is concerning to humans for various reasons including recreational interference, economic turmoil for fishing communities, and depleted fish resources.[4]

Body Plan edit

As an adult, the compass jellyfish has an average diameter of 24 cm, ranging from 15-38 cm.[3] It usually has 16 brown elongated V-shaped markings on the translucent yellow-white bell. The markings surround a central brown spot and resemble the face of a compass, hence the common name 'compass jellyfish'.[1] It is usually colored yellowish white, with some brown. Its 24 tentacles are arranged in eight groups of three. Each tentacle has stinging cells for capturing prey and defense from predators.[5] A sense organ is located between each group of tentacles, which can perceive changes in light and helps the jellyfish determine and maintain its position in the water column.[1] It has 4 oral arms that can be distinguished from the tentacles because the arms are noticeably longer and have a folded, frilly appearance.[5] These arms are used to facilitate transfer of captured prey from the tentacles to the mouth which is between the oral arms at the center of the underside of the bell.[5]

Habitat edit

 
Chrysaora hysoscella in Vancouver Aquarium
Video of the Chrysaora hysoscella (compass jellyfish) from the Monterey Bay Aquarium

The compass jellyfish is usually found relatively close to shore,[2] predominantly in coastal waters of the northeast Atlantic, particularly the Celtic, Irish and North Seas.[6] It is also known to inhabit the southern Atlantic Ocean, particularly the Mediterranean Sea and coastal regions of South Africa and False Bay[7][6]. They inhabit these waters mostly at the top of the water column,[8][9] and although they inhabit shallow water, they move up and down in the water column often ranging from surface waters to just above the seabed.[8] They are rarely found deeper than 30 m from the surface.[8][2]

Feeding and Predation edit

Compass jellyfish are carnivores, consuming other marine invertebrates and plankton.[3] They feed on a variety of benthic and pelagic organisms including but not limited to: dinoflagellates, copepods, crustacean eggs, larval fish, and chaetognaths.[3] They stun and capture their prey with stinging cells on their tentacles.[1] The oral arms facilitate movement of captured prey into the oral opening.[5] Compass jellyfish have very few predators. They are known to be consumed by the leatherback sea turtle and ocean sunfish.[7]

Life Cycle edit

Like other Scyphozoans, Chrysaora hysoscella undergo metamorphosis as the organism develops and experiences a polyp and then medusa form. Females release planular larvae which swim to find a suitable place to settle. The planulae attach to a benthic substrate and develop into a sessile polyp which releases immature medusae through asexual reproduction called strobilation.[10][11] Chrysaora hysoscella function as a male upon maturity and then develop female gametes, meaning this organism is classified as protandrously hermaphroditic.[12][11]

Reproduction edit

Chrysaora hysoscella utilize both sexual and asexual reproduction throughout development.[12] Mature individuals reproduce sexually by broadcast spawning. Males release sperm from their mouths into the water column.[1] Females fertilize the sperm internally and can fertilize sperm from multiple male partners.[12] The larvae released from the female settle as benthic polyps that reproduce asexually.[11] The polyps release multiple ephyrae through strobilation.[10] Ephyrae are the earliest form of the medusa stage. Research indicates that Chrysaora hysoscella polyps are capable of releasing ephyrae overtime and therefore are not limited to a single reproductive event.[11][10]

Parasite Hyperia medusarum edit

Adult Chrysaora hysoscella are often parasitised by Hyperia medusarum. C. hysoscella found inshore and closer to the surface are more likely to have the parasite. The parasite can be found inside of the body cavity in the umbrella and gonads but tends to move from umbrella to gonads if there is space for them there. The gonads are more enriched in Carbon and protein content then any other part of the body, making this region the ideal location to settle and feed. They have also been found on the oral arms of the jellyfish where they can eat prey caught by the medusae.[2]

Effects of Global Warming edit

Scyphozoa populations are increasing with the warming climate and warmer ocean temperatures. Studies suggest that warmer winter temperatures allow for a longer strobilation period and subsequently higher ephyra production per polyp, higher percentages of polyp strobilation, and higher polyp survival rate. Polyps will be more successful in warmer temperatures but not in extreme temperatures. C. hysoscella are predicted to migrate further northwards to maintain ideal conditions.[10]

Impact edit

Thriving jellyfish populations have been found to take over as top predators in areas that fin fish have been over-exploited[3]. Increased abundance of jellyfish negatively impacts fish populations in the same region because jellyfish feed on fish eggs and larvae.[9] Jellyfish and larval fish can also share common dietary preferences. Competition for food resources can result in depleted fish populations. Overpopulation of jellyfish is a concern to humans for many reasons.[4] Jellyfish stings are painful and sometimes deadly to humans. Fishing nets can be overwhelmed with jellyfish bycatch or torn by jellyfish caught in the nets. Jellyfish can clog water inlets to power plants, causing serious problems for power production. Jellyfish can invade aquaculture cages, ruining the production of the organism being farmed.[4]

References edit

  1. ^ a b c d e f g Dawson, Kailyn; Giordano, Cara. "Chrysaora hysoscella Compass jellyfish". Animal Diversity Web. University of Michigan Museum of Zoology.
  2. ^ a b c d Beucher, E; Sparks, C; Brierley, A; Boyer, H; Gibbons, M (2001). "Biometry and size distribution of Chrysaora hysoscella (Cnidaria, Scyphozoa) and Aequorea aequorea (Cnidaria, Hydrozoa) off Namibia with some notes on their parasite Hyperia medusaru". Journal of Plankton Research. 23 (10): 1073.
  3. ^ a b c d e Flynn, B.A.; Gibbons, M.J. (2007). "A note on the diet and feeding of Chrysaora hysoscella in Walvis Bay Lagoon, Namibia, during September 2003". African Journal of Marine Science. 29 (2): 303–307. doi:10.2989/AJMS.2007.29.2.15.197.
  4. ^ a b c Vince, Gaia. "Jellyfish blooms creating ocean of slime". BBC.
  5. ^ a b c d "Chrysaora". Britannica. Encyclopedia Britannica.
  6. ^ a b Doyle, T; Houghton, J; Buckely, S; Hays, G; Davenport, J (2007). "The broad-scale distribution of five jellyfish species across a temperate coastal environment". Hydrobiologia. 579: 29–39.
  7. ^ a b Jones, Georgina. A field guide to the marine animals of the Cape Peninsula. SURG, Cape Town, 2008. ISBN 978-0-620-41639-9
  8. ^ a b c Hays, Graeme C.; Doyle, Thomas K.; Houghton, Jonathan D. R.; Lilley, Martin K. S.; Metcalfe, Julian D.; Righton, David (27 January 2008). "Diving behaviour of jellyfish equipped with electronic tags". Journal of Plankton Research. 30 (3): 325–331. doi:10.1093/plankt/fbn003. Retrieved 2 May 2016.
  9. ^ a b Sparks, Conrad; Buecher, Emmanuelle; Brierley, Andrew S.; Axelsen, Bjørn E.; Boyer, Helen; Gibbons, Mark J. (2001). Jellyfish Blooms: Ecological and Societal Importance. Springer Netherlands. pp. 275–286. doi:10.1007/978-94-010-0722-1_22. ISBN 978-94-010-3835-5.
  10. ^ a b c d Holst, S; Jarms, G (2012). "Effects of low salinity on settlement and strobilation of Schyphozoa (Cnidaria): Is the lion's mane Cyanea capillata (L.) able to reproduce in the brackish Baltic Sea" (PDF). Hydrobiologia. 645.
  11. ^ a b c d Holst, S; Jarms, G (2007). "Substrate choice and settlement preferences of planula larvae of five scyphozoa (Cnidaria) from German Bight, North Sea". Marine Biology. 151 (3): 863–871.
  12. ^ a b c Piraino, S.; DeVito, D.; Shmich, J.; Bouillon, J.; Boero, F. (2006). "Evidence of reverse development in Leptomedusae (Cnidaria, Hydrozoa): the case of Laodicea undulata (Forbes and Goodsir 1851)". Marine Biology. 149 (2): 339-346.

External links edit

  Media related to Chrysaora hysoscella at Wikimedia Commons

Category:Semaeostomeae Category:Articles containing video clips Category:Animals described in 1766




Article evaluation

I evaluated the article on Scyphozoa. All of the information in the article was relevant to the topic and there were no distracting elements on the page. In the "Commercial importance" section they mentioned that certain types of jellies cause disruptions to the fishing industry but they didn't explain what happened. The article should include more information on this. I learned about it in one of my marine science classes and it's an interesting tid bit that would be useful to know. Since it was included in the article there must be a reliable source that mentions it. If there is no reliable source then the statement should be removed. The only other improvement i would suggest is to add more images, maybe a diagram of the symmetry mentioned in the "Anatomy" section.

The article was neutral, with no apparent biases or inappropriate claims. I was surprised that there was no mention of jellyfish overpopulation in the article. The sources I checked were reliable sources and the links did work.

On the talk page there is very little discussion. There is a discussion about removing the term "true jellyfish" from the page because it can be misleading for readers who do not understand what this means. This article is a part of two projects: "Animals" where it is rated C-Class and High importance, and "Marine Life" where it is also rated C-Class and High importance. The only discussion topic on the talk page is similar to things we discuss in class. It acknowledges that the term "true jellies" was coined because Schyphozoa are the kinds of jellies people are usually referring to when talking about jellyfish. This is something we learn about in marine biology classes.


Article Selection

Turritopsis nutricula is my first choice for my project. The current article is a stub. I found several articles about this species including Morphological and ultrastructural analysis of Turritopsis nutricula during life cycle reversal (10.1016/S0040-8166(03)00028-4), Morphological modification during the reverted life cycle of Turritopsis nutricula, Reversing the life cycle: Medusae transforming into polyps and cell transdifferentiation in Turritopsis nutricula (Cnidaria, Hydrozoa) (10.2307/1543022), and Turritopsis nutricula. These are all from the Web of Science database, I would search other databases for additional sources.

Oxycomanthus japonicus is my second choice for my project. There is currently no article on wikipedia for this species. I found several articles about this species including Staging of Regeneration Process of an Arm of the Feather Star Oxycomanthus japonicus Focusing on the Oral-Aboral Boundary (DOI: 10.1002/dvdy.22429), Nervous system development of two crinoid species, the sea lily Metacrinus rotundus and the feather star Oxycomanthus japonicus (DOI: 10.1007/s00427-010-0317-5), Ciona intestinalis and Oxycomanthus japonicus, Representatives of Marine Invertebrates (10.1538/expanim.58.459), and Development and Growth of the Feather Star Oxycomanthus japonicus to Sexual Maturity (DOI: 10.2108/zsj.25.1075). These are from one database, I would look at other databases for additional sources.

Chrusaora hysoscella if my third choice for my project. The current article is a stub. I found several articles about this species including Biometry and size distribution of Chrysaora hysoscella (Cnidaria, Scyphozoa) and Aequorea aequorea (Cnidaria, Hydrozoa) off Namibia with some notes on their parasite Hyperia medusarum (DOI: 10.1093/plankt/23.10.1073), Observations on the distribution and relative abundance of the scyphomedusan Chrysaora hysoscella (Linne, 1766) and the hydrozoan Aequorea aequorea (Forskal, 1775) in the northern Benguela ecosystem (DOI: 10.1023/A:1011829516239), A note on the diet and feeding of Chrysaora hysoscella in Walvis Bay Lagoon, Namibia, during September 2003 (DOI: 10.2989/AJMS.2007.29.2.15.197), Effects of food and CO2 on growth dynamics of polyps of two scyphozoan species (Cyanea capillata and Chrysaora hysoscella) (DOI: 10.1007/s00227-015-2660-6). These are the results from just one database, I would look at other databases for additional sources.

All three are great choices - Josh

intro: The compass jellyfish (Chrysaora hysoscella) is a very common species of jellyfish that inhabits the coastal waters in cold and temperate regions of the Atlantic Ocean. It is a 'true' jellyfish displaying radial symmetry with distinct brown markings shaped like elongated V's on its bell. This organism has a benthic polyp stage before developing into a pelagic adult medusae. Compass jellyfish consume a variety of marine invertebrates and plankton and are preyed on by very few.

possible sections and subsections for article: -habitat:

lives in coastal waters of the Atlantic and Mediterranean, including near the United Kingdom, Ireland and Turkey. It is also known from the southern Atlantic Ocean from the west coast of South Africa and False Bay[1] (already in article)

found in coastal areas of the northeast Atlantic Ocean, particularly in the Celtic, Irish, and North Seas (greatest abundance between 50.0°–52.0° N). They are also found in the Mediterranean Sea and coastal regions of South Africa.

Combined: the compass jellyfish is found predominantly in coastal waters of the northeast Atlantic ocean, particularly the Celtic, Irish and North Seas. It is also known to live in the southern Atlantic ocean, particularly the Mediterranean Sea and coastal regions of South Africa


-feeding and predation Compass jellyfish are carnivores, consuming other marine invertebrates and plankton. They feed on a variety of benthic and pelagic organisms including but not limited to: dinoflagellates, copepods, crustacean eggs, larval fish, and chaetognaths. They stun and capture their prey with stinging cells on their tentacles. The oral arms facilitate movement of captured prey into the oral opening. Compass jellyfish have very few predators. They are known to be consumed by leatherback sea turtles and ocean sunfish.

-parasite Hyperia medusarum

Adult Chrysaora hysoscella are often parasitised by Hyperia medusarum. Ch. hysoscella found inshore and closer to the surface are more likely to have the parasite. The parasite can be found inside of the body cavity in the umbrella and gonads but tends to move from umbrella to gonads if there is space for them there. The gonads are more enriched in Carbon and protein content then any other part of the body, making this region the ideal location to settle and feed. They have also been found on the oral arms of the jellyfish where they can eat prey caught by the medusae. (Biometry and size distribution of Chrysaora hysoscella (Cnidaria, Scyphozoa) and Aequorea aequorea (Cnidaria, Hydrozoa) off Namibia with some notes on their parasite Hyperia medusarum By:Buecher, E (Buecher, E); Sparks, C (Sparks, C); Brierley, A (Brierley, A); Boyer, H (Boyer, H); Gibbons, M (Gibbons, M)) already cited in article i believe.

-I think there should be a section called "feeding" or something, and within it you could have a subsection on mechanisms and then on diet. I think parasites/diseases should go in a section of its own at the end of the article, and maybe add a couple other ailments if there are any. I think the info here is good but needs to be reorganized, its a little cluttered.

-migration? -global/economic/environmental impact -effects of climate warming on strobilation

Generally, Schypozoa populations are increasing with the warming climate and warmer ocean temperatures. Studies suggest that warmer winter temperatures allow for a longer strobilation period and subsequently higher ephyra production per polyp, higher percentages of polyp strobilation, and higher polyp survival rate. Polyps will be more successful in warmer temperatures but not in extreme temperatures. C. hysoscella are predicted to migrate further North to maintain ideal conditions. (Effects of climate warming on strobilation and ephyra production of North Sea scyphozoan jellyfish)

- Don't use sentences like "a study by so-and-so suggests..." instead say "It is thought that warmer winter..." and then cite it. That way it doesn't sound like it has any sort of bias. I think that this bit would work better as a subsection of the reproduction section. I like the idea of a global/econ/enviro impact, as far as how it impacts economies or habitats. Maybe add an "impacts" section and then have a subsection for econ and enviro each.


-life cycle/life history females release planular larvae which swim to find a suitable place to settle. they attach to a benthic substrate and develop into a sessile polyp which releases immature medusae through asexual reproduction called strobilation. these medusae can revert back to the polyp stage and release more meduasae or continue to develop into adults. once an adult it cannot revert back to a polyp but does develop from male to female. Since Chrysaora hysoscella function as a male upon maturity and then develop female gametes, this organism is classified as protandrously hermaphroditic. -body plan As an adult, the compass jellyfish has a diameter of up to 30 cm. It has a flattened bell-shaped body with tentacles, arms and a mouth on the underside. It usually has 16 brown elongated V-shaped markings on the translucent yellow-white bell. The markings surround a central brown spot and resemble the face of a compass, hence the common name 'compass jellyfish'. It is usually colored yellowish white, with some brown. Its 24 tentacles are arranged in eight groups of three. Each tentacle has stinging cells for capturing prey and defense from predators. A sense organ is located between each group of tentacles, which can perceive changes in light and helps the jellyfish determine and maintain its position in the water column. It has 4 oral arms that can be distinguished from the tentacles because the arms are noticeably longer and have a folded, frilly appearance. These arms are used to facilitate transfer of captured prey from the tentacles to the mouth which is between the oral arms at the center of the underside of the bell.

-reproduction (expand on strobilation) Chrysaora hysoscella utilize both sexual and asexual reproduction throughout development. Mature individuals reproduce sexually by broadcast spawning. Males release sperm from their mouths into the water column. Females fertilize the sperm internally and can fertilize sperm from multiple male partners. The larvae released from the female settle as benthic polyps that reproduce asexually. The polyps release multiple ephyrae through strobilation. The ephyrae then develop into medusae. Research indicates that Chrysaora hysoscella polyps are capabable of releasing ephyrae overtime and therefore are not limited to a single reproductive event.

- I don't know if this would work, but it might be cleaner to organize it into subsections for each portion of the life cycle, but I don't know if there is enough info. Body plan should either be it's own section, or just discussed in the intro paragraph.

Notes from sources