Stolidobranchia

Gold sea squirt ( Polycarpa aurata ), including the white bryozoans Triphyllozoon inornatum.

The Stolidobranchia (Size: gills and intestine with streamers ) or Pleurogona are sessile live tunicates ( Tunicata, Urochordata ) and are used in traditional systematics therefore to the class of " sea squirts " ( Ascidiacea ) were counted. The animals are sometimes very often. In the Rotalgenzone the western Baltic Sea can provide three-quarters of the total zoomass the Tangbeere ( Dendrodoa grossularia ).

Features

Most species of the group, such as people living in the Mediterranean Red sea squirt, are solitary and are relatively large. Animal poles forming species there are in the family Styelidae. Your body has no limbs, the intestines are on the side of gills intestine, which is traversed by longitudinal vessels and wrinkles. The unpaired gonads lie to the left and right of the body wall, the cloacal cavity develops from a dorsal unpaired invagination.

Outer systematics

The sea squirts do not form a monophyletic group by DNA sequence analysis. A cladogram shows the probable actual relationship of tunicates. The Stolidobranchia are the basal sister group to all other taxa:

Stolidobranchia ( " sea squirts " )

Phlebobranchia ( " sea squirts " )

Salps ( Thaliacea )

Aplousobranchia ( " sea squirts " )

Appendikularien ( Larvacea )

Families

  • Hexacrobylidae Seeliger, 1906
  • Molgulidae Lacaze - Duthiers, 1877
  • Plidaeuridae
  • Pyuridae Hart Meyer, 1908
  • Styelidae Sluiter, 1895
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