Spotted jelly
Mastigias papua, Monterey Bay Aquarium, Monterey, California
Mastigias papua is an umbrella jellyfish ( Scyphozoa ) that is found in lagoons and lakes island in the Pacific Ocean. The species has been found by their mass occurrence in Ongeim'l Tketau ( Jellyfish Lake ) on the island of Koror island upstream Eil Malk ( Palau ) a certain notoriety among diving sports fans and in the media. The taxonomic status of the species and its ubiquity is, however, discussed the basis of new morphological and molecular data. It is probably more of a Artkomplex of several cryptic species.
Features
The hemispherical shade can have a diameter up to 200 mm reach ( ssp. salii ). The base color is bluish surface is covered with fine warts. The basic color of individual subspecies has, however, modified by the incorporation of zooxanthellae to light brown. Between the eight shielding cloth deep furrows are formed. Oral arms reach approximately half the length of the screen diameter. The upper third of the arm is simple, the lower two-thirds of a triptych. The arms usually end in a clavate thickening. The arms may be greatly reduced in some subspecies. The rhopalialen channels are slender and branch out.
Distribution, occurrence and life
According to the data published so far is the kind of Indonesia in the west, across the Philippines to Japan, and spread to the south across New Guinea to Palau. Should confirm the recent molecular biological data, the range of the actual Mastigias papua would probably be severely limited. The animals live in lagoons, brackish water lakes, marine lakes and mangroves.
Taxonomy and Nomenclature
The distribution and extent of the species has been hit hard by new morphological and molecular studies in doubt. The species was first completely revised 1910 by Alfred Goldsborough Mayer. The holotype of the species comes from Waigeo, the largest island of the four main islands of Raja Ampat archipelago off West New Guinea (Indonesia). So far, no copy from the locus typicus with newer methods could be investigated. Recent studies from other localities, however, provide the previously assumed wide geographical distribution of the species in doubt. Dawson ( 2004, 2005 ) presented large molecular biological and morphological differences as well as differences in the lifestyles of the populations of Mastigias papua in the various marine lakes and the adjacent open lagoons on Palau determine which justify definitely a separation on subspecies level. Specimens from the mouth of Berau (East Kalimantan ) and from Tufi ( Oro Province, Papua New Guinea also have a very large molecular genetic distance to populations on Palau, lying on type - level. Thus there are probably at least three cryptic species before. the locations of the three populations studied ( Berau, Tufi and Palau ), however, are each over 1000 km from the locus typicus of Mastigias papua away. Excluding material from the type locality, it is currently not possible to decide which of the three populations studied Mastigias papua or whether even a fourth kind hides in the Artkomplex which is previously known as Mastigias papua. It is therefore more likely that the populations of Palau are unable to provide to Mastigias papua, but represent a separate species. Around this taxonomic to be able to go step but is also an examination of the remaining species of the genus Mastigias (M. albipunctata Stiasny, 1920, M. andersoni Stiasny, 1926, M. gracilis ( Vanhoffen, 1888 ), M. ocellatus ( Modeer, 1791 ), M. pantherinus Haeckel, 1880, M. roseus ( Reynaud, 1830) and M. Sidereus Chun, 1896), which have been described from the Indian Ocean and western Pacific based on morphological differences, is necessary. It must also be taken into account that Alfred Goldsborough Mayer has synonymized in his great summary work " Medusae of the World" is another type (of Japan ), and a variety with Mastigias papua, which could well be their own independent species according to the above experiences. Here again, no data are available yet. Mastigias papua is in its present form a Artkomplex of at least three, even more five or more cryptic species. Therefore, by Dawson ( 2005) established subspecies are in five different marine lakes on Palau as Mastigias cf papua ssp. referred to.
- Mastigias cf papua ssp. remengesaui Dawson, 2005 ( UET era Ongael, Ongael, Koror, Palau ). The species is characterized by numerous, different-sized white spots on the Exumbrella. Inter-and perradiale channels, the mouth close to lots of tentacles and their tips are often colored blue. The screen has a brown color, which is caused by the zooxanthellae. The planktonic medusae are about 15 cm tall. They are only occasionally frequent, but also missing completely at certain times. They can be found from a depth of around 4 m to the lake level.
- Mastigias cf papua ssp. nakamurai Dawson, 2005 ( Goby Lake, Ngermeuangel, Koror, Palau ) The brown color is in small medusae complemented by bruising. For smaller and larger medusae also yellow spots at the screen edge are available. The medusae are about 15 cm tall. They come throughout the year before in the water column from 0 to 7 m.
- Mastigias cf papua ssp. etpisoni Dawson, 2005 ( " Jellyfish Lake " Ongeim'l Tketau, Mecherchar, Koror, Palau ). The medusae are brown, with no blue pigmentation, fine white spots rarely occur. Otherwise, no stains are present. The thickened end portions of the eight arms oral relatively short and wide. The largest jellyfish grow up to 23 cm. The medusae are planktonic and usually the whole year round in the water column from 0 to 13 m depth available.
- Mastigias cf papua ssp. saliii Dawson, 2005 ( Clear Lake, Koror, Palau ). The light brown color caused by the zooxanthellae is complemented by a blue pigmentation in the inter-and perradialen channels. The thickened end portions of the eight oral arms are short to medium in length and lanceolate. The medusae are up to 20 cm tall. They live in depths 0-9 m and are usually quite often. You can also completely missing. The salinity of the water is at the time of occurrence of medusae significantly decreased ( from 22.6 to 28.1 psu. Polyps are found in 6-7 m depth on decomposing leaves.
- Mastigias cf papua ssp. remeliiki Dawson, 2005 ( UET era Ngermeuangel, Ngermeuangel, Koror, Palau ). The color is golden brown owing to the embedded zooxanthellae. Spots on the Exumbrella missing in most copies. But what you provided, they are frequently and irregularly shaped. The blue pigment is completely absent. The thickened end portions of the eight oral arms are paddle-shaped, lanceolate or rarely tricuspid and always very short. The medusae are about 8 to 12 inches tall. The medusae come throughout the year before in the water column ( 0-16 m). The water is usually slightly brackish ( 24.5 to 31.5 psu). The polyps were attached in about 6 to 16 m water depth to hard substrates, decaying leaves and wood have been found.
The subspecies caused by the isolation of populations of Lagunenart by rising sea levels after the last interglacial period. The sinks are on karst cavities with the sea in conjunction; the lake level approximately equal to the sea level. This means that the deepest lakes ( " Jellyfish Lake " Ongeim'l Tketau: 60 m deep ) are also the oldest lakes and can not be older than 12,000 years old.