Notaspidea

In the subordination Nudibranche (Greek νῶτον: back, άσπις: Shield ) or Pleurobranchacea ( πλευρά: side, flank, βράγχια: gills), German Flankenkiemer or Seitenkiemer, even back plate screw, a heterogeneous group of opisthobranch, both housing bearing snails and slugs were summarized. The eponymous for the German designation feature is an external right gill. The taxon is omitted in the taxonomy of Bouchet & Rocroi ( 2005).

• 2.1 Current classification by Bouchet & Rocroi (2005)
• 2.2 Old classification by Ponder & Lindberg (1997)

Features

Anatomy

Characteristics of Flankenkiemer are an external Federkieme ( Cteniden ) on the right side, a shallow dish and rolled rhinophores. The snails of the families Tylodinidae and Umbraculidae that recall of the unrelated limpets and are therefore also called " false slugs " have large outer shells and a small jacket. When Pleurobranchidae family, the conditions are reversed: You have a clearly visible shell and an inner shell. The shell is a product of evolutionary regression in the adult stage and may even be completely absent.

Nutrition

Grown Flankenkiemer are meat or scavengers.

Protection mechanisms

Many species produce toxic skin secretions to defend themselves.

System

The taxon Nudibranche 1883 drawn up by the French zoologist Paul Henri Fischer, who in this case the two families Pleurobranchidae Menke, 1828 ( sea slugs to side -lying external feathery gills ) and Tylodinidae Gray, 1847 ( marine gastropods napfschneckenähnlichem housing and right -lying external feathery gills ) summarized. This group was also adopted by Johannes Thiele (1929-1935) in its recognized until the 1990s taxonomy of the worm. The monophyly of the group was challenged in 1985 by Louise Schmekel and since then rejected by several other authors. The characterizing feature of the Federkieme on the right side of the body, was now considered Plesiomorphie and the species as a paraphyletic group. However, the Nudibranche dive yet into the scheme of Ponder & Lindberg (1997 ), in which they include the families Pleurobranchidae Menke, 1828 Tylodinidae Gray, 1847, and Umbraculidae Dall, 1889. Bouchet & Rocroi (2005) reject the group in the currently accepted classification of snails, which is based on molecular genetic studies, and represent the two previously summarized groups in different taxa within the opisthobranchs. The Umbraculoidea which comprise the Umbraculidae and Tylodinidae, hereafter are a sister group of the Cephalaspidea with which they are among the Euopisthobranchia while forming the Pleurobranchidae with the nudibranchs, their sister group, the Nudipleura.

Current classification by Bouchet & Rocroi (2005)

In the taxonomy of Bouchet & Rocroi (2005) the taxon Nudibranche was retired.

The families of the Nudibranche went into the new clades Nudipleura (H. Wägele & R. C. Willan, 2000), Umbraculida (W. H. Dall, 1889 ) and the new superfamilies Pleurobranchoidea (J. E.Gray, 1827), Umbraculoidea (W. H. Dall, 1889) on. The superfamilies have been introduced for the sake of consistency and the discoverers of the names attributed to giving families.

• Class Gastropoda Cuvier, G., 1797 Clade Heterobranchia J. E. Gray, 1840 informal group Opisthobranchia H. Milne Edwards, 1848 Clade Aplysiomorpha P. H. Fischer, 1883
• Clade Cephalaspidea P. H. Fischer, 1883
• Clade Gymnosomata H. M. D. de Blainville, 1824
• Clade Nudipleura Wägele H. & R. C. Willan, 2005 Superfamily Nudibranchia H. M. D. de Blainville, 1814
• Superfamily Pleurobranchoidea J. E. Gray, 1827 Family Pleurobranchidae J. E. Gray, 1827

• Superfamily Umbraculoidea W. H. Dall, 1889 (1827) Family Tylodinidae J. E. Gray, 1847
• Family Umbraculidae W. H. Dall, 1889 (1827)

Old classification by Ponder & Lindberg (1997)

• Class Gastropoda Cuvier, G., 1797 Subclass Orthogastropoda F. W. Ponder & D. R. Lindberg, 1995 Subclass Apogastropoda L. Salvini - Plawen & G. Haszprunar, 1987 Superorder Heterobranchia J. E. Gray, 1840 Group Euthyneura J. W. Spengel, 1881 H. Milne Edwards 1848 order Opisthobranchia Subordination Nudibranche P. H. Fischer, 1883 Family Pleurobranchidae J. E. Gray, 1827
• Family Tylodinidae J. E. Gray, 1847
• Family Umbraculidae W. H. Dall, 1889