Olindiidae

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Olindiidae
Olindias formosa

Olindias formosa

Systematics
without rank: Tissue animals (Eumetazoa)
Trunk : Cnidarians (Cnidaria)
Class : Hydrozoa (Hydrozoa)
Subclass : Trachylinae
Order : Limnomedusae
Family : Olindiidae
Scientific name
Olindiidae
Haeckel , 1879

The Olindiidae (often also Olindiasidae, Olindiadidae, earlier also Olindiadae) are a family of Limnomedusae within the cnidarians (Cnidaria).

features

The Olindiidae are metagenetic , relatively small Hydrozoa with a polyp stage and mostly a free-living medusa stage. Only eumedusoids that are free or that remain connected to the polyps are seldom formed. The relatively very small polyps are mostly solitary , rarely they also form colonies. They rarely grow over a millimeter in size. They can be tentacles (and thus "reduced"), or they can have one or more tentacles arranged in a circle. A differentiation of the polyps into dactylozooids (defense polyps) can also be observed occasionally. They do not have an actual theca, but a periderm cup is often formed. In some species the mouth is elongated like a snout. The polyps reproduce very actively asexually through budding, the formation of podocysts and through so-called frustules, worm-shaped structures that can actively move and can grow into polyps after a migration. In some species, polyps can also regress to frustration. The medusas in smaller pools are often of the same sex. This indicates that they are descended from one (or possibly several, coincidentally same-sex) polyp (s). The podocysts are drought-resistant and can even be transported with the wind after a pond has dried up.

The medusas are one to 60 mm in diameter. Centripetal channels may or may not be present. The radial channels are unbranched. The gonads are located along the radial canals or, rarely, on the manubrium (e.g. Limnocnida ). There are no ocelli . The medusa of individual species can have up to 400 or more tentacles. The tentacles can be differentiated. In at least some species, the sex products are released into the open water, where fertilization takes place. Planula-like larvae develop from the fertilized eggs, and after a while they become attached and become polyps. Medusa formation is temperature controlled in at least some species; H. Medusas are only formed at higher temperatures. In Craspedacusta sowerbii , medusa form only from 26 to 27 ° C. Then a polyp can constrict a medusa about every 17 days. The species can therefore not form medusa for several years if these conditions are not achieved in a body of water; it then only reproduces asexually.

Among the species of the Olindiidae family there are often strikingly colored species (such as Olindias phosphoricus ).

Geographical occurrence and way of life

The species of the family are distributed worldwide in the seas, both in the tropics and in the cold seas. However, the family is also home to a number of species that live in fresh and / or brackish water. Craspedacusta sowerbii has now been abducted worldwide.

They live on small crustaceans, rotifers and protozoa .

Systematics

A separate family Limnocnididae is excreted by some older authors. On the other hand, the genus Limnocnida , type genus of the family Limnocnididae, is usually placed in the family Olindiidae in more recent works . The World Hydrozoa Database lists 17 genera for the Olindiidae family with a total of 46 species (including some nomina dubia).

swell

Individual evidence

  1. ↑ Andrew McClary: The Effect of Temperature on Growth and Reproduction in Craspedacusta Sowerbii. Ecology, 40 (1): 158-162, Washington, DC 1959 ISSN  0012-9658
  2. ↑ World Hydrozoa Database - olindiidae

literature

  • Jean Bouillon, Cinzia Gravili, Francesc Pagès, Josep-Maria Gili and Fernando Boero: An introduction to Hydrozoa. Mémoires du Muséum national d 'Histoire naturelle, 194: 1-591, Publications Scientifiques du Muséum, Paris 2006 ISBN 978-2-85653-580-6
  • Marymegan Daly, Mercer R. Brugler, Paulyn Cartwright, Allen G. Collin, Michael N. Dawson, Daphne G. Fautin, Scott C. France, Catherine S. McFadden, Dennis M. Opresko, Estefania Rodriguez, Sandra L. Romano & Joel L. Stake: The phylum Cnidaria: A review of phylogenetic patterns and diversity 300 years after Linnaeus. Zootaxa, 1668: 127-182, Wellington 2007 ISSN  1175-5326 Abstract - PDF
  • Bernhard Werner: Cnidaria tribe . In: Textbook of Special Zoology. Volume I: Invertebrates Part 2: Cnidaria, Ctenophora, Mesozoa, Plathelminthes, Nemertini, Entoprocta, Nemathelminthes, Priapulida. 4th completely revised edition, pp. 11–305, Gustav Fischer Verlag, Stuttgart 1984 ISBN 3-437-20261-8

Web links

Commons : Olindiidae  - Collection of images, videos and audio files

annotation

  1. ↑ The correct form of the surname can not be clearly determined even if the International Rules for Zoological Nomenclature are interpreted to the letter . Family names are formed by adding the ending -idae to the stem of the type genus. Olindias is an arbitrary word formation and should therefore be treated as a proper name, i.e. of non-classical origin. This means that "... for the purposes of the rules, the strain that the author who has introduced a new taxon of the family group has decided to retain; ..." ( IRZN Art. 29.3.3). Haeckel (1879) was the first to introduce a subfamily Olindiadae. Basically, his treatment of the family name would be decisive. However, it is not clear in his work what he has assumed as the tribe of Olindias (e.g. tribe Olindias-, from which Olindiasidae = contracted to Olindiadae, or tribe Olindia-, from which Olindiaidae, or stem Oliandiad-, from which Olindiadidae = in the latter two cases to Olindiadae). What is fairly certain, however, is that he did not adopt Olindi as a tribe, otherwise he would have written Olindiidae or, together, Olindidae. Ernst Haeckel created other (sub-) surnames with the ending -idae. "If the spelling of a name of the family group does not correspond to Article 29.3 in its formation, but the name is in predominant use, this spelling must be retained -..." (Article 29.5). At the moment this is Olindiidae despite the use of the notation Olindiasidae in Daly et al. (2007). The "World Hydrozoa Database" has meanwhile deviated from the notation Olindiasidae and now also uses the notation Olindiidae. The sex of the genus Olindias was not given by Fritz Müller and cannot be derived from the only originally assigned species. In such a case, the gender of the genus is to be assumed as male (IRZN Art. 30.2.3)