''Mastigias'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of true

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

in the family

Mastigiidae Mastigiidae is a family of true jellyfish. The family is native to the Indo-Pacific, but a species of ''Mastigias'' has been introduced to the West Atlantic, and ''Phyllorhiza punctata'' has been introduced to the West Atlantic and Mediterranea ...

. It contains seven described

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

. Members of this

are found widely in coastal regions of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, including saline lakes of

Palau Palau,, officially the Republic of Palau and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country and microstate in the western Pacific. The nation has approximately 340 islands and connects the western chain of the Caro ...

(e.g.,

Jellyfish Lake Jellyfish Lake ( pau, Ongeim'l Tketau, lit=Fifth Lake) is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror an ...

), but there are also records from the West Atlantic at

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

and

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

. The West Atlantic records are most likely the result of accidental introductions by humans.

Species

According to the ''

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

'', this genus includes seven

: * ''

Mastigias albipunctatus ''Mastigias'' is a genus of true jellyfish in the family Mastigiidae. It contains seven described species. Members of this genus are found widely in coastal regions of the Indo-Pacific, including saline lakes of Palau (e.g., Jellyfish Lake), bu ...

'' * ''

Mastigias andersoni ''Mastigias'' is a genus of true jellyfish in the family Mastigiidae. It contains seven described species. Members of this genus are found widely in coastal regions of the Indo-Pacific, including saline lakes of Palau (e.g., Jellyfish Lake), bu ...

'' * ''

Mastigias gracilis ''Mastigias'' is a genus of true jellyfish in the family Mastigiidae. It contains seven described species. Members of this genus are found widely in coastal regions of the Indo-Pacific, including saline lakes of Palau (e.g., Jellyfish Lake), bu ...

'' * ''

Mastigias ocellatus ''Mastigias ocellatus'', the golden medusa, is a species of jellyfish in the family Mastigiidae. It is native to the southern Pacific Ocean. Description The medusa of ''M. ocellatus'' grows to a diameter of about . The surface of the bell is sc ...

'' – golden medusa * ''

Mastigias pantherinus ''Mastigias'' is a genus of true jellyfish in the family Mastigiidae. It contains seven described species. Members of this genus are found widely in coastal regions of the Indo-Pacific, including saline lakes of Palau (e.g., Jellyfish Lake), bu ...

'' * ''

Mastigias papua The spotted jelly (''Mastigias papua''), lagoon jelly, golden medusa, or Papuan jellyfish, is a species of jellyfish from the Indo-Pacific oceans. Like corals, sea anemones, and other sea jellies, it belongs to the phylum Cnidaria. ''Mastigias p ...

'' – spotted jelly * ''

Mastigias siderea ''Mastigias siderea'' is a species of jellyfish in the family Mastigiidae. It is native to the southern Pacific Ocean. Description The medusa of ''M. siderea'' grows to a diameter of about . There are about 60 marginal lappets and the surface ...

Synapomorphies

For reproduction, ''Mastigias'' pupua has adopted a mono-mode reproductive strategy that develops only free-swimming buds. ''Mastigias'' organisms also are able to produce swimming frustules, a hard and porous cell wall covering diatoms. Mastigias papua 04

Habitat

The genus ''Mastigias'' is native to the western and central Indo-Pacific, from Australia to Japan, and Micronesia to the Indian Ocean. However, most ''Mastigias'' organisms choose to live in landlocked marine lakes. Behavioral differences among this genus do occur with varying habitats. Marine lake ''Mastigias''' swim slower than their oceanic ancestors. The ''Mastigias'' genus may have to adapt to a habitat with warmer temperatures. With growing temperature deviation above the average, organisms within this genus have seen a decrease in population as well as growing mortality rates.

Interactions

Mastigias jellyfish have a symbiotic relationship with zooxanthellae living in host gastrodermal cells where they exhibit phased division. The ''Mastigias'' genus of jellyfish symbiotically produce ephyrae only in the presence of Symbiodinium, in a process called stobilation.

References

{{Taxonbar, from=Q3298068 Mastigiidae Scyphozoan genera