Ganesha (genus)
| Ganesha | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the order | ||||||||||||
| Ganeshida | ||||||||||||
| Moser , 1908 | ||||||||||||
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| Ganeshidae | ||||||||||||
| Moser, 1907 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Ganesha | ||||||||||||
| Moser, 1907 | ||||||||||||
| species | ||||||||||||
Ganesha is a genus of the rib jellyfish (Ctenophora) from the class Tentaculata . It was described in 1907 by the Swiss zoologist Fanny Moser . The genus combines the characteristics of different orders like a mosaic, so that it is the only genus in the monotypical family of Ganeshidae and the order of Ganeshida. The genus comprises two species, both of whichhave been foundvery rarely in the Indian Ocean .
construction
Ganesha has an elongated, oval, very thin-walled body in a lateral view, which is flattened in the plane of the tentacles . The mouth and throat (pharynx) are unusually wide. Inward, this leads to the central “stomach”, the infundibulum . At the rear (aboral) end it branches into two sections, these lengthen into two paragastric channels , which finally run past the throat to the side of the mouth, where they form a (circumoral) ring channel surrounding the mouth (whether this ring channel is completely closed, but is unknown). The eight meridional canals are perpendicular to the main body axis of the animals, they run on the side facing away from the mouth under the comb ribs and also open into the ring canal. The ribs of the same length on the outside carry the rows of eyelashes characteristic of the trunk, these are relatively large in Ganesha , but few, they are broad at the base and narrow towards the outside.
The structure of the Ganeshida is similar to that of the Lobata rib jellyfish as well as that of the Cydippida species: the uncompressed body, which is circular in cross section, has a large mouth (but not as with these two mouth lobes) and no auricles , cone-shaped, flagellated appendages like those of the Lobata.
Ganesha use two very small, heavily branched tentacles to catch prey , which arise from tentacle sheaths at the edge of the mouth and can be withdrawn into them.
distribution and habitat
Both species have been caught, rarely, in coastal waters of the Indian Ocean. The species Ganesha annamita has never been found since it was first described in 1946.
Systematics
The Ganeshida belong to the group of tentacle-bearing rib jellyfish. Their exact systematic position is unclear, according to morphological arguments the Lobata could be their sister group . In molecular analyzes, e.g. B. phylogenetic DNA analyzes, they could not be included so far, since no gene sequences are known and no material that could be analyzed was available.
There are two types . The species Ganesha elegans was also described by Fanny Moser, originally as Lampetia elegans , based on material from Indonesia and later transferred to the new genus Ganesha by herself . The order Ganeshida was re-established for the species by Moser after their new and better preserved material was available from the island of Ambon . Ganesha annamita was described in 1946 by the Russian-born zoologist Constantin Dawydoff .
swell
- Ganeshida at WoRMS World Register of Marine Species , accessed February 10, 2016.
- Fanny Moser (1908): Cténophores de la Baie d'Amboine. Revue Suisse de Zoologie 16 (1): 1–26.
- Paul Simion: Les cténophores: de leur position dans l'arbre des métazoaires (approche phylogènomique) à leur diversité taxonomique (phylogénie moléculaire et anatomie comparée). Zoology des invertébrés. Université Pierre et Marie Curie, Paris 2014 ( online , French).