Periphylla periphylla

Geographic Range

Periphylla periphylla can be found in numerous locations around the world including the South Shetland Islands, South Sandwich Islands, South Georgia Island, the Southern Ocean, Antarctica, the Antarctic Peninsula, and other marine habitats worldwide. The only large body of water they are not found in is the Arctic Ocean. While it has a wide distribution, P. periphylla is significantly more abundant in some Norwegian Fjords. (BBC, 2005; Brueggeman, 1998; Dupont and Aksnes, 2010)


These members of the Class Scyphozoa live anywhere from the surface to 1000 meters deep in the ocean. At night, or when feeding, they may get closer to the surface. This vertical migration occurs particularly at latitudes farther from the equator, as is the case of medusae under ice in Antarctica. Much research has focused on the abundance of P. periphylla in Norwegian fjords, where the distribution follows a vertical layering pattern. Distribution also seems to be strongly affected by the location of food, as well as physical conditions. For example, P. periphylla may not approach the surface if strong winds result in turbulence.

Periphylla periphylla tends to live in deeper waters in subtropical and tropical regions. Depths vary with latitude, as it can live in shallow areas north of 42°N. This species likely submerges when it is closer to the equator due to the temperature of the water in the surface layer. Periphylla periphylla can survive temperatures up to 19.8 °C, although most specimens are collected at temperatures between 4 °C and 11 °C. There may be a connection between temperature tolerance, temerature-dependent metabolic rates, and food supply. Vertical mixing can also affect the jellyfish's submerging at a certain latitude.

The vertical location of these jellyfish is also linked to light intensity. The pigment that gives P. periphylla red-brown color can have a lethal affect when exposed to light. Since light intensity is based on depth, individuals tend to migrate to depths with relatively low light exposure. (Arai, 1997; BBC, 2005; Bamstedt, et al., 2003; Brueggeman, 1998; Dupont and Aksnes, 2010; Jarms, et al., 2002; Kaartvedt, et al., 2007)

  • Range depth
    1000 to surface m
    3280.84 to ft
  • Average depth
    500 m
    1640.42 ft

Physical Description

Periphylla periphylla are deep-sea medusae with twelve stiff tentacles, which extend from a thick, bell shaped body. These animals have dark red and/or brown stomachs, and are bioluminescent. They can be up to 20 cm long, and their bodies, or central domes, have a diameter of up to 35 cm. The coronal groove, located on the lower portion of the bell, helps to contain prey, and also provides flexibility for movement. The coronal groove divides the aboral surface into the central dome and the peripheral zone, which contains radial thickenings called pedalia and marginal lappets that contain some sense organs. This zone also contains the tentacles, which are useful in moving prey to the mouth. The mouth is very simple and is located on the manubrium. Externally, males and females of this species are similar. No indication of geographical or seasonal variation was reported.

The pigment that gives P. periphylla their red-brown color is protoporphyrin (also known as porphyrin), which can lead to tissue damage as a result of photosynthesis. The pigment is not harmful to this species as they do not usually stay in shallow waters.

Periphylla periphylla contain relatively high levels of lactate dehydrogenase, an enzyme important to anaerobic metabolic functions. This is likely useful for movement in ocean layers with minimal amounts of oxygen.

The Q10 value of an organism is its temperature coefficient- the factor of change in respiration caused by an increase in temperature of 10 °C. The value for P. periphylla, calculated in the range of 5°C - 10°C, was found to be 2.6. This value indicates that temperature affects the biochemical reactions of the organism. A value of 1 would mean that the organism is insensitive to temperature.

The water content of P. periphylla is 95.7 - 96.6 percent of the total wet weight. The measured salinity of the surrounding water when this was measured was 33.1-33.3 percent.

Periphylla periphylla are one of the only five scyphozoan species that is bioluminescent. The bioluminescence, along with with its red-brown coloring and the direction of its tentacles, make it easy to distinguish. The blue or blue-green light emission occurs as a result of stimulation and is concentrated in specific parts of the organism, such as the marginal lappets and near the coronal groove. Members of these species exhibit bioluminescence as a response to a short pulse of alternating current with a series of flashes. (Arai, 1997; BBC, 2005; Brueggeman, 1998)

  • Sexual Dimorphism
  • sexes alike
  • Range length
    20 (high) cm
    7.87 (high) in


Studies on live specimens obtained from Lurefjorden in Norway showed the life cycle of P. periphylla involves direct development from egg to young medusae, lacking a planula, polyp stage, and an ephyra stage.

The life cycle contains a total of 14 developmental stages. Stage 1, which can last anywhere from 1 to 10 days, are the eggs, which are relatively large, and at first are sessile and on average, do not live as deep as fully grown individuals. In Stage 2 (5-14 days in duration), the egg has flattened slightly in the middle. In stage 3, the first signs of the coronal groove can be seen. In Stage 4 (6-16 days in duration), wavy structures may be observed, as well as radial lines pointing toward what will become the mouth. This is also the stage in which the first movements occur. By Stage 5, marginal lappets will have appeared, and the coronal groove is clearly visible. The main feature of Stage 6 is the newly developed tentacle buds. In this stage, one may also see larger marginal lappets, and the organism will have started to regain a spherical shape. Bell pulsations allow it to swim. The pigment porphyrin increases during development, although it first becomes visible in Stage 7, when the mouth also forms. In Stage 8, the tentacles are the same length as the marginal lappets, and the central disc begins to flatten. Individuals resembling young medusa, begin feeding and are fully motile in Stage 9. At this stage, marginal lappets will be at least 0.9 mm long. The duration of development from Stage 1 to 9 is estimated to last 2-3 months.

Pigmentation develops in the tips of the twelve tentacles by Stage 10. The pigmentation continues to spread in Stage 11, and by Stage 12, the tentacles are completely pigmented. In Stage 13, the marginal lappets and the coronal furrow are pigmented, and the pigment continues to move towards the bell.

The final stage, Stage 14, is when the medusa is completely pigmented. In this stage gonads appear and sexual dimorphism can be observed, however, the process of sex determination is unknown. At the end of this stage, the individual is a fully mature medusa.

Members of this species are bioluminescent, exhibiting a blue fluorescence, during all stages of life. (BBC, 2005; Jarms, et al., 2002)


While very little is known about the details of reproduction of P. periphylla, mating most likely occurs near the surface. One observation is that only mature individuals are found near the surface, whereas smaller, immature individuals tended to stay a little lower, even at night. Examination of these mature specimens revealed gonads with mature sperm or eggs (respective to the determined sex). Little is also known about the social structure of P. periphylla.

The life-cycle of P. periphylla does not depend on season, so at any one time, an individual may be at a different stage. Reproduction occurs year round.

Observers have also noted that patches of these medusae seem to be denser in water that have dust and foam, which might indicate that individuals take advantage of water movements in order to aggregate.

While there is little more conclusive knowledge about the mating behaviors of P. periphylla, observed behaviors are similar to those of Tripedalia cystophora and Carybdea sivickisi, whose individuals exhibit internal fertilization, achieved by the male holding the female until sperm is transferred. However, since it is now known that these individuals continuously spawn, it is possible that they exhibit external fertilization. In order to conclusively determine what occurs, further observations are required. (Tiemann and Jarms, 2010; Tiemann, et al., 2009)

Periphylla periphylla breeds year-round. Individuals of this species are either male or female, and they reproduce sexually. Very little is known about fertilization in this species, including whether external or internal fertilization occurs. The frequency of breeding has not been determined.

Individuals of this species undergo direct development, growing gradually in size throughout their 14 stages of development, from egg to sexual maturity. While the time from stage 1 to 9 is believed to be 2-3 months, the length of time until sexual maturation is still unknown.

Female members of this species continuously produce a few, relatively large, eggs over a long period of time. Upon maturation they spawn (release gametes) continuously.

One unique feature of P. periphylla that separates it from other species of the Order Coronatae is that the medusae have complete and fully developed follicles. (Jarms, et al., 2002; Tiemann and Jarms, 2010; Tiemann, et al., 2009)

  • Breeding interval
    The breeding interval of Periphylla periphylla is currently undetermined.
  • Breeding season
    Periphylla periphylla breed year-round.

Observations of parental involvement of mature P. periphylla have not been made. Other scyphozoan species, however, do not display this behavior. (Arai, 1997)

  • Parental Investment
  • no parental involvement


Little is known about the lifespan of P. periphylla. However, individuals of this species may have relatively long lives compared to similar species, perhaps as much as several decades. Mortality might be slightly lower in Norwegian Fjords, where this species is abundant. The life span of these jellyfish is also affected by light exposure, which may cause its pigments to have a lethal affect on the individual.

Due to the large geographic range of P. periphylla, factors such as local predation and food availability should be taken into account while determining regional lifespans. For example, in clear water, predators might be more likely to find medusae, so the average lifespan may be lower.

Periphylla periphylla are difficult to maintain and raise for long periods of time, which may explain why no data have been recorded regarding the longevity of these medusae in captivity. (BBC, 2005; Dupont and Aksnes, 2010; Jarms, et al., 1999; Sornes, et al., 2008)

  • Average lifespan
    Status: wild
    30 years


Few details of the behavior of young P. periphylla are available. Adults are free-swimming (motile). Movement is largely due to pulsations caused by the organism's strong radial deltoid muscles in the bell. These muscles extend to the coronal muscle from the gastric region and are important in modifying the swimming beat (speed) of the individual.

The majority of individuals in this species swim with their tentacles first in the aboral direction. A second, less common swimming position is when the tentacles are placed perpendicular to the direction of movement.

The shape of the bell suggests that these medusae were designed to remain stationary and act as ambushers, moving only once prey has made contact. Their constant swimming is therefore considered very unusual.

Most P. periphylla display vertical migration behavior. These individuals stay in lower layers during the day, and move to upper layers during the night. This pattern of migration may be linked to the migration of one of their food sources, krill.

Details regarding social interactions between members of this species, if any, are unknown. (Arai, 1997; Kaartvedt, et al., 2007; Sornes, et al., 2008)

Home Range

Home ranges of P. periphylla are not known.

Communication and Perception

Periphylla periphylla are bioluminescent at all stages of life, and this bioluminescence may be used as a warning to predators. Periphylla periphylla react to light - it can be lethal to those mature individuals. Members of this species lack an acoustically sensitive organ (such as the gas bladder of fish) and react very little to sound. They also react to tactile stimulation, producing bioluminescent light that spreads from the point of stimulation to the nerve nets of the individual. (Bamstedt, et al., 2003; Jarms, et al., 2002; Kaartvedt, et al., 2007)

  • Communication Channels
  • visual

Food Habits

Periphylla periphylla use tentacles to grasp their prey, and with the help of marginal lappets, bend them inwards to transfer the prey into the mouth of the individual. Some research has indicated that the location of prey has an effect on the movement of these medusae.

One of the earliest studies that was conducted on the diets of different scyphozoans included P. periphylla. Fourteen specimens contained food, and 100% of the prey were copepods, the majority being calanoid copepods. These medusae also feed on krill (such as Meganyctiphanes norvegica), a type of zooplankton, as well as chaetognaths and ostracods. They may also eat small fish and other medusae. (Arai, 1997; BBC, 2005; Kaartvedt, et al., 2007; Sornes, et al., 2008)

  • Animal Foods
  • fish
  • aquatic crustaceans
  • cnidarians
  • other marine invertebrates
  • zooplankton


In the Northern Atlantic ocean, two common predators of P. periphylla at depths of below 1000 meters are Alepocephalus bairdii and Coryphaenoides rupestris. A third predator is the pelagic shrimp Notostomus robustus. Along with nematocysts, the bioluminescence could be a form of defense, as it may repel potential predators by signaling danger or distastefulness. Anemones, such as Isotealia antarctica, are also potential predators, as well as sea spiders, if they are able to make contact with an individual. (Arai, 1997; Brueggeman, 1998; Jarms, et al., 2002)

Ecosystem Roles

Pelagic amphipods, genus Hyperia, live on, or even in, P. periphylla. It has not yet been determined if they are parasitic.

Periphylla periphylla are predators of copepods, krill, chaetognaths, and ostracods. They are also the prey of organisms such as Alepocephalus bairdii and Coryphaenoides rupestris. (Arai, 1997; BBC, 2005; Brueggeman, 1998; Jarms, et al., 2002; Sornes, et al., 2008)

Economic Importance for Humans: Positive

Due to their role as both predator and prey to other species, P. periphylla is part of several food webs, and it is possible that its presence is necessary to maintain the populations of its prey, and to the survival of its predators. This could, consequently, affect fishing industries. However, there are no well documented benefits that P. periphylla provide to humans.

Economic Importance for Humans: Negative

The large abundance of P. periphylla in Norwegian fjords has impacted the local fishing industry, as they clog the nets used by fishermen. There have been no adverse effects of this species on humans reported in any other regions. (Dupont and Aksnes, 2010)

Conservation Status

Periphylla periphylla is not a species that is not considered to be threatened, and it does not appear in any animal conservation databases. Much of the research done on this species has been sparked by the abundance of these medusae in Norwegian fjords. (BBC, 2005)

Other Comments

Periphylla periphylla are known by several names, including duncecaps and helmet jellies. (Brueggeman, 1998)


Bhavna Singichetti (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, Renee Mulcrone (editor), Special Projects.



lives on Antarctica, the southernmost continent which sits astride the southern pole.

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

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Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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living in the southern part of the New World. In other words, Central and South America.

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Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

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living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.


an animal that mainly eats meat


uses smells or other chemicals to communicate


having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.


(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.


specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.


found in the oriental region of the world. In other words, India and southeast Asia.

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An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).


generates and uses light to communicate


an animal that mainly eats plankton


the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

radial symmetry

a form of body symmetry in which the parts of an animal are arranged concentrically around a central oral/aboral axis and more than one imaginary plane through this axis results in halves that are mirror-images of each other. Examples are cnidarians (Phylum Cnidaria, jellyfish, anemones, and corals).

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).


uses sight to communicate

year-round breeding

breeding takes place throughout the year


animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)


Arai, M. 1997. A Functional Biology of Scyphozoa. Boundary Row, London: Chapman & Hall.

BBC, 2005. "Periphylla" (On-line). Accessed April 27, 2011 at

Bamstedt, U., S. Kaartvedt, M. Youngbluth. 2003. An evaluation of acoustic and video methods to estimate the abundance and vertical distribution of jellyfish. Journal of Plankton Research, 25 (11): 1307-1318. Accessed April 27, 2011 at

Brueggeman, P. 1998. "Cnidaria – Scyphozoa: jellyfish" (On-line). Scripps Institution of Oceanography Library : UC San Diego. Accessed April 27, 2011 at

Dupont, N., D. Aksnes. 2010. Simulation of optically conditioned retention and mass occurrences of Periphylla periphylla. Journal of Plankton Research, 0 (00): 1-11. Accessed April 27, 2011 at

Jarms, G., H. Tiemann, U. Bamstedt. 2002. Development and biology of Periphylla periphylla (Scyphozoa: Coronatae) in a Norwegian fjord. Marine Biology, 141 (4): 647-657.

Jarms, G., U. Bamstedt, H. Tiemann, M. Martinussen, J. Fossa. 1999. The holopelagic life cycle of the deep-sea medusa Periphylla periphylla (Scyphozoa, Coronatae). Sarsia, 84: 55-65.

Kaartvedt, S., T. Klevjer, T. Torgersen, T. Sornes, A. Rostad. 2007. Diel vertical migration of individual jellyfish (Periphylla periphylla). Limnology and oceanography, 52 (3): 975-983. Accessed April 27, 2011 at

Lucas, C. 2009. Biochemical composition of the mesopelagic coronate jellyfish Periphylla periphylla from the Gulf of Mexico. Journal of the Marine Biological Association of the United Kingdom, 89 (01): 77-81. Accessed April 27, 2011 at

Shimomura, O., P. Flood. 1998. Luciferase of the scyphozoan medusa Periphylla periphylla. The Biological Bulletin, 194: 244-252.

Sornes, T., D. Aksnes, U. Bamstedt, M. Youngbluth. 2007. Causes for mass occurrences of the jellyfish Periphylla periphylla; an hypothesis that involves optically conditioned retention. Journal of Plankton Research, 29 (2): 157-167. Accessed April 27, 2011 at

Sornes, T., A. Hosia, U. Bamstedt, D. Aksnes. 2008. Swimming and feeding in Periphylla periphylla (Scyphozoa, Coronatae). Marine Biology, 153: 653-659.

Tiemann, H., G. Jarms. 2010. Organ-like gonads, complex oocyte formation, and long-term spawning in Periphylla periphylla (Cnidaria, Scyphozoa, Coronatae). Marine Biology, 157 (3): 527-535.

Tiemann, H., I. Sotje, B. Johnston, P. Flood, U. Bamstedt. 2009. Documentation of potential courtship-behaviour in Periphylla periphylla (Cnidaria: Scyphozoa). Journal of the Marine Biological Association of the United Kingdom, 89 (1): 63-66. Accessed April 27, 2011 at