Siphonariidae

Siphonaria zelandica

The Siphonariidae are a family of marine snails küstenbesiedelnder from the order of snails ( Pulmonata ). In English they are called " false limpets " ( false limpets ); In German there is no popular name. They are small to medium-sized snails, which absorb oxygen from the air through the lungs serving as the mantle cavity.

Features

The empty shells can be easily by looking at the inside of the true limpets, with whom they are not related, are different. Here can be found in the Siphonariidae a well recognizable lateral furrow on the right side shell and a corresponding interruption of annular Muskelansatzaufwölbung. At this point, is located in the living animal's blowhole ( Pneumostom ), ie the inlet and outlet opening of the lung.

Way of life

So far investigated, the animals growing from the loose on the rocks small algae they can rasp with their radula feinzähnigen feed. Fixed in the rock encrusted algae can not be included ..

The animals can, as in the Hawaiian Style Siphonaria alternata was shown to exhibit a so-called homing behavior, ie they both return to their starting point.

Distribution and number of species

The Siphonariidae are widespread in tropical to temperate - cold regions of the world. Distribution area are the Litoralgebiete on the southern hemisphere. You can also occur in brackish water. In Europe, only the genus Siphonaria occurs (eg Siphonaria pectinata on the coast of Gibraltar ). There are 75-78 species described.

Paleontology

The family is fossil since the Upper Jurassic ( Oxfordian, approximately 160 million years ago ) is known.

System

External system: The family is temporarily here for paraphyletic group of water snails in the broader sense ( " Basommatophora " ) expected. Their exact position in the taxonomic system is not yet finally resolved. In many cases they will be provided along with the only fossil described family of † Acroreiidae in its own superfamily Siphonarioidea. † The Acroreiidae can be found in the steps of the Coniacian ( about 87 million years ago ) through Ypresium ( about 50 million years ago). The recent findings are from brackish deposits in the Paris Basin. Because of their poverty but the unique feature of classification and assignment of † Acroreiidae and thus also the superfamily Siphonarioidea remains uncertain.

Internal system: There are the following five genera:

  • Known Benhamina Finlay, 1927, only one species ( Benhamina obliquata Sowerby ), New Zealand
  • Kerguelenella A.W. Baden Powell, 1946; 1-3 species; Patagonia, New Zealand, sub-Antarctic islands
  • Pugillaria Iredale, 1924; Prob only one type ( Pugillaria stowae, South Australia and Tasmania )
  • Siphonaria G. B. Sowerby I, 1823; about 67 species worldwide
  • Williamia di Monterosato, 1884; 5-6 species, inter alia, North America
John Edward Gray Patellidae Oxfordian (stage)
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