Craspedacusta sowerbyi
Encyclopedia
Craspedacusta sowerbyi is a freshwater jellyfish in the phylum Cnidaria
. Since it is classified as a hydrozoan, it is one of many jellyfish
that are also known as hydromedusae ("medusa" is another word for jellyfish). Hydromedusan jellyfish differ from scyphozoan jellyfish because they have a muscular, shelf-like structure called a velum
on the ventral surface, attached to the bell margin. C. sowerbyi is found throughout the world in bodies of fresh water.
reservoirs, lake
s, impoundments, gravel pits or quarries
. They have also been seen in river systems such as the Allegheny River
, the Ohio River
and the Tennessee River
in the United States
and the Wang Thong River
of Thailand
. They prefer standing water, and are not generally seen in fast flowing streams or rivers.
C. sowerbyi has a global distribution - it has been found in countries on almost every continent (so far there are no reports from South America) and nearly every state in America (no reports yet from Montana, Wyoming, North Dakota, South Dakota, Alaska or Hawaii) and most provinces in Canada (no reports yet from Alberta, Saskatchewan).
C. Sowebyi has also been recently found in the Cauvery river of Karnataka, India , and backwaters of the Hemavathi River in Hassan in Karnataka
Recently, Dr. Marco Antonio Moreno León reported the first record of the freshwater jellyfish Craspedacusta sowerbyi (Lankester 1880) in Mexico; the jellyfish was collected in Adolfo Lopez Mateos (ALM) reservoir, one of the main reservoirs in Sinaloa State NW in Mexico. This report of the population of C. sowerbyi represents an exceptional case of freshwater jellyfish at this latitude on the American Continent.
The medusa's appearance is sporadic and unpredictable from year to year. It is not uncommon for C. sowerbyi to appear in a body of water where it had never been documented before, in very large numbers, and its appearance may even be reported on the local news.
During the abnormal heat in the summer 2010 in Russia sightings of C. sowerbyi were reported in the Moscow river.
On August 21st 2010, C. sowerbyi was spotted and captured on the northwest corner of Falcon Lake in Manitoba
, Canada
. Scientists believe this is due to a recent heatwave in the Whiteshell Provincial Park
area. It is proposed the C. sowerbyi came to Falcon Lake
on waterfowl
originating from Star Lake, Manitoba
, Canada
. Falcon Lake along with Star Lake remain the only two confirmed sightings of C. sowerbyi in Manitoba
.
including daphnia
and copepods. Prey is caught with their stinging tentacles. Drifting with its tentacles extended, the jelly waits for suitable prey to touch a tentacle. Once contact has been made, nematocysts on the tentacle fire into the prey, injecting poison
which paralyzes the animal, and the tentacle itself coils around the prey. The tentacles then bring the prey into the mouth, where it is released and then digested.
, which lives in colonies attached to underwater vegetation, rocks, or tree stumps, feeding and asexually reproducing
during spring and summer. Some of these offspring are the sexually reproducing
medusa
e. Fertilized eggs develop into small ciliated larva
e called planula
. The planula then settle to the bottom, and develop into polyps. However, the majority of C. sowerbyi populations existing in the United states are either all male or all female, so there is no sexual reproduction in those populations.
During the cold winter months, polyps contract and become resting bodies, called podocysts. It is believed that podocysts are transported by aquatic plants or animals to other bodies of water. Once conditions become favorable, they develop into polyps again.
Cnidaria
Cnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance,...
. Since it is classified as a hydrozoan, it is one of many jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
that are also known as hydromedusae ("medusa" is another word for jellyfish). Hydromedusan jellyfish differ from scyphozoan jellyfish because they have a muscular, shelf-like structure called a velum
Velum
Velum may refer to:* Superior medullary velum, part of the nervous system that stretches between parts of the brain* Veil , the veil-like membrane of immature mushrooms extending from the margin of the cap to the stem and torn by growth...
on the ventral surface, attached to the bell margin. C. sowerbyi is found throughout the world in bodies of fresh water.
Form
C. sowerbyi medusae are about 20–25 mm in diameter, somewhat flatter than a hemisphere, and very delicate, when fully grown. They have a whorl of up to 400 tentacles tightly packed around the bell margin. Hanging down from the center of the inside of the bell is a large stomach structure called a manubrium, with a mouth-opening with four frilly lips. Circulation of nutrients is facilitated by four radial canals which originate at the edges of the stomach (manubrium), and which are also connected to a ring canal, located near the bell margin. Most of the body is transparent or translucent, with a whitish or greenish tinge. The (usually) four large flat sex organs (gonads) are attached to the four radial canals, and are usually opaque white. The many tentacles each contain thousands of cells called cnidocytes, which contain nematocysts (also known as cnidocysts), and are used to capture prey and pass it to the mouth. Food is taken in the mouth opening, and waste is finally expelled out of the same opening.Habitat and Distribution
C. sowerbyi is usually found in calm, freshwaterFreshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
reservoirs, lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, impoundments, gravel pits or quarries
Quarries
Quarries - The "Royal Quarries" — not found in Scripture — is the namegiven to the vast caverns stretching far underneath the northern hill, Bezetha, on which Jerusalem is built. Out of these mammoth caverns stones, a hard limestone, have been quarried in ancient times for the buildings in the...
. They have also been seen in river systems such as the Allegheny River
Allegheny River
The Allegheny River is a principal tributary of the Ohio River; it is located in the Eastern United States. The Allegheny River joins with the Monongahela River to form the Ohio River at the "Point" of Point State Park in Downtown Pittsburgh, Pennsylvania...
, the Ohio River
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...
and the Tennessee River
Tennessee River
The Tennessee River is the largest tributary of the Ohio River. It is approximately 652 miles long and is located in the southeastern United States in the Tennessee Valley. The river was once popularly known as the Cherokee River, among other names...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and the Wang Thong River
Wang Thong River
The Wang Thong River is a river in Thailand. Its source lies in the Phetchabun Mountains in the Khao Kho District, Thailand.It flows through Thung Salaeng Luang National Park and forms Namtok Sri Dit and Namtok Kaeng Sopha in the Wang Thong District of Phitsanulok Province, and finally flows...
of Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
. They prefer standing water, and are not generally seen in fast flowing streams or rivers.
C. sowerbyi has a global distribution - it has been found in countries on almost every continent (so far there are no reports from South America) and nearly every state in America (no reports yet from Montana, Wyoming, North Dakota, South Dakota, Alaska or Hawaii) and most provinces in Canada (no reports yet from Alberta, Saskatchewan).
C. Sowebyi has also been recently found in the Cauvery river of Karnataka, India , and backwaters of the Hemavathi River in Hassan in Karnataka
Recently, Dr. Marco Antonio Moreno León reported the first record of the freshwater jellyfish Craspedacusta sowerbyi (Lankester 1880) in Mexico; the jellyfish was collected in Adolfo Lopez Mateos (ALM) reservoir, one of the main reservoirs in Sinaloa State NW in Mexico. This report of the population of C. sowerbyi represents an exceptional case of freshwater jellyfish at this latitude on the American Continent.
The medusa's appearance is sporadic and unpredictable from year to year. It is not uncommon for C. sowerbyi to appear in a body of water where it had never been documented before, in very large numbers, and its appearance may even be reported on the local news.
During the abnormal heat in the summer 2010 in Russia sightings of C. sowerbyi were reported in the Moscow river.
On August 21st 2010, C. sowerbyi was spotted and captured on the northwest corner of Falcon Lake in Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. Scientists believe this is due to a recent heatwave in the Whiteshell Provincial Park
Whiteshell Provincial Park
Whiteshell Provincial Park is a 2,729 km2 park centrally located in Canada in the province of Manitoba. It can be found in the southeast of the province along the Manitoba-Ontario border, approximately 130 km east of Winnipeg. The park is located in the Canadian Shield region and has many...
area. It is proposed the C. sowerbyi came to Falcon Lake
Falcon Lake
Falcon Lake may refer to:*Falcon Lake , Canada*in the United States**Falcon International Reservoir , formed by the international crossing at Falcon Dam**Falcon Lake **Falcon Lake...
on waterfowl
Waterfowl
Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....
originating from Star Lake, Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. Falcon Lake along with Star Lake remain the only two confirmed sightings of C. sowerbyi in Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
.
Feeding
C. sowerbyi is a predator on zooplanktonZooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
including daphnia
Daphnia
Daphnia are small, planktonic crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style...
and copepods. Prey is caught with their stinging tentacles. Drifting with its tentacles extended, the jelly waits for suitable prey to touch a tentacle. Once contact has been made, nematocysts on the tentacle fire into the prey, injecting poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
which paralyzes the animal, and the tentacle itself coils around the prey. The tentacles then bring the prey into the mouth, where it is released and then digested.
Natural history
C. sowerbyi begins life as a tiny polypPolyp
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body...
, which lives in colonies attached to underwater vegetation, rocks, or tree stumps, feeding and asexually reproducing
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
during spring and summer. Some of these offspring are the sexually reproducing
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
medusa
Medusa (biology)
In biology, a medusa is a form of cnidarian in which the body is shaped like an umbrella, in contrast with polyps. Medusae vary from bell-shaped to the shape of a thin disk, scarcely convex above and only slightly concave below...
e. Fertilized eggs develop into small ciliated larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e called planula
Planula
A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species. The planula forms from the fertilized egg of a medusa, as the case in scyphozoans and some hydrozoans, or from a polyp, as in the case of anthozoans...
. The planula then settle to the bottom, and develop into polyps. However, the majority of C. sowerbyi populations existing in the United states are either all male or all female, so there is no sexual reproduction in those populations.
During the cold winter months, polyps contract and become resting bodies, called podocysts. It is believed that podocysts are transported by aquatic plants or animals to other bodies of water. Once conditions become favorable, they develop into polyps again.
External links
- http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=1068 USGS' page about C. sowerbyi
- http://www.jellyfish.iup.edu An authoritative and detailed website about Craspedacusta sowerbyi
- http://www.microscopy-uk.org.uk/mag/artdec99/fwjelly2.html
- http://www.microscopy-uk.org.uk/mag/artnov99/fwjelly.html
- Kaeng Bang Rachan at Tourism Authority of Thailand (reference to freshwater jellyfish in the Wang Thong River in Thailand)
- GLANSIS Species FactSheet