''Mastigias'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of true

jellyfish Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animal ...

in the family

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

. It contains seven described

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

. 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, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

(e.g., Jellyfish Lake), but there are also records from the West Atlantic at

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

and

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

. 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 catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

'', this genus includes seven

: * '' Mastigias albipunctatus'' * '' Mastigias andersoni'' * '' Mastigias gracilis'' * '' Mastigias ocellatus'' – golden medusa * '' Mastigias pantherinus'' * '' Mastigias papua'' – spotted jelly * '' Mastigias siderea''

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

strobilation Strobilation or transverse fission is a form of asexual reproduction consisting of the spontaneous transverse segmentation of the body. It is observed in certain cnidarians and helminths. This mode of reproduction is characterized by high offspri ...

References

{{Taxonbar, from=Q3298068 Mastigiidae Scyphozoan genera