Genus Pseudorhiza Von Lendenfeld, 1882

Museums

Regional Maps

• Pseudorhiza Von Lendenfeld, R. 1882. Über eine übergangsform zwischen Semostomen und Rhizostomen. Zoologischer Anzeiger 5: 380–383 [380].

  Type species:

   Pseudorhiza aurosa Von Lendenfeld, 1882 by subsequent designation, see Mayer, A.G. 1910. Medusae of the World. Vol. 1 and 2, The Hydromedusae. Vol. 3, The Scyphomedusae. Washington, D.C. : Carnegie Institution 735 pp., 76 pls. [reprinted by A. Asher & Co., 1977] [682].
• Monorhiza Haacke, W. 1887. Die Scyphomedusen des St. Vincent Golfes. Jenaische Zeitschrift für Naturwissenschaft 20: 588–638, 3 pls [614].

  Type species:

   Pseudorhiza haeckelii Haacke, 1884 (=Monorhiza haeckelii (Haacke, 1887)) by original designation.

Taxonomic Decision for Synonymy

• Mayer, A.G. 1910. Medusae of the World. Vol. 1 and 2, The Hydromedusae. Vol. 3, The Scyphomedusae. Washington, D.C. : Carnegie Institution 735 pp., 76 pls. [reprinted by A. Asher & Co., 1977] [682]

Introduction

The genus Pseudorhiza has a long and complicated nomenclatural history, a summary of which has recently been submitted for publication (Gershwin & Zeidler, in review).

Briefly, pending publication, von Lendenfeld (1882) described the species P. aurosa, and figured it with 8 symmetrically-placed appendages, i.e., one on each moutharm; this form has not been reported since, and is likely to be apocryphal. Haacke (1884) described the species P. haeckelii, with only a single asymmetrically-placed appendage, i.e., one on one moutharm. Occasionally specimens are found with two moutharms, and once I have seen a photograph of a specimen with three moutharms, but by a huge margin, one is the norm. To emphasize this difference, Haacke (1887) subsequently moved his species to the genus Monorhiza, which has not been adopted by other authors.

However, this form was previously described by Péron & Lesueur (1810) under the names Favonia octonema and Lymnorea triedra. Both of these species were long regarded as unidentifiable hydromedusae (except by Agassiz, 1862: 159, who treated them as obscure rhizostomes), and as such were eventually suppressed from the scientific literature.

Distribution

States

Northern Territory, South Australia, Tasmania, Victoria, Western Australia

Diagnosis

Lychnorhizidae with mouth-arms with very long terminal clubs, with or without filaments between the mouths; eight radial canals reaching bell margin, eight only reaching ring canal; in each of the 16 spaces 10 centripetal unbranched, blind vessels.

Diagnosis References

Kramp, P.L. 1961. Synopsis of the medusae of the world. Journal of the Marine Biological Association of the United Kingdom 40: 1-469 [367]

General References

Agassiz, L. 1862. Contributions to the Natural History of the United States of America. Second monograph. In five parts — Pt. I Acalephs in general. Pt. II Ctenophore. Pt. III. Discophorae. Pt. IV. Hydroidae. Pt. V. Homologies of the Radiata. Boston, London : Little Brown, Trubner Vol. IV i-viii, 380 pp. + (1-10), pls 20-35. [159]

Haacke, W. 1884. Pseudorhiza haeckelii, sp.n. der Endspross des Discomedusenstammes. Biologisches Zentralblatt 4: 291–294 [291]

Haacke, W. 1887. Die Scyphomedusen des St. Vincent Golfes. Jenaische Zeitschrift für Naturwissenschaft 20: 588–638, 3 pls

Péron, F. & Lesueur, C.A. 1810. Tableau des caractères génériques et spécifiques de toutes les espèces de méduses connues jusqu'à ce jour. Annales du Muséum National d'Histoire Naturelle. Paris 14: 325–366

Von Lendenfeld, R. 1882. Über eine übergangsform zwischen Semostomen und Rhizostomen. Zoologischer Anzeiger 5: 380–383 [380]

History of changes