Ptychogastriidae

from Wikipedia, the free encyclopedia
Ptychogastriidae
Ptychogastria asteroides

Ptychogastria asteroides

Systematics
Trunk : Cnidarians (Cnidaria)
Class : Hydrozoa (Hydrozoa)
Subclass : Trachylina
Order : Trachymedusae
Family : Ptychogastriidae
Scientific name
Ptychogastriidae
Mayer , 1910

The Ptychogastriidae are a family of jellyfish from the order of trachymedusae .

features

The Ptychogastriidae have eight radial canals and have neither stalk nor centripetal canals. Your stomach stalk (manubrium) is either simple without mesenteries or eight-lobed with eight mesenteric sections. The gonads sit either on the manubrium, on the manubrial lobes, or on the radial canals next to the manubrial lobes.

The edge tentacles, some of which are provided with adhesive discs, are either grouped in bundles or are concentrated on the different levels of the outer screen. In the latter case they are particularly numerous. The club-shaped sense organs ( statocysts ) are free.

Way of life and distribution

Unlike many other Trachymedusae, they do not belong to the plankton but to the epibenthos , i.e. they live close to the ground. Ptychogastria polaris can be found in arctic waters, Tesserogastria musculosa has so far only been found in a fjord near Oslo.

Systematics

The family contains two genera with a total of three species with another dubious fourth species.

swell

  • 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
  • PL Kramp: Synopsis of the Medusae of the World. , in: Journal of the Marine Biological Association of the United Kingdom, 1961, Vol. 40, p. 243, PDF Online
  • FS Russell: Trachymedusae. , in: Fich. Ident. Zooplancton, Vol.164, 1980, pp. 3-4, PDF online

Individual evidence

  1. ↑ World Hydrozoa Database -Ptychogastriidae