Family OIKOPLEURIDAE

Museums

Museum list

Regional Maps

Family OIKOPLEURIDAE

Compiler and date details

P. Kott, Queensland Museum, Brisbane, Queensland, Australia

Introduction

Oikopleuridae have ovoid bodies, straight endostyles, and the spiracles have tubular passages from the internal pharyngeal openings to the external ones in the vicinity of the rectum. Stomach walls have numerous small cells and a row of only a few large cells. A row of large (Fol's) fibroblasts is on both parts of the antero-dorsal oikoplast epithelium.

Appendicularia flagellum Chamisso, 1821, the first recorded organism of the class, although barely recognisable at family level, has a species description and accompanying figures that make the general affinity of the organism clear enough (see Fenaux 1993). Mertens (1830) believed that he had the same species from the Bering Strait but renamed it Oikopleura chamissonis. Fenaux (1993) believes that either Oikopleura labradoriensis Lohmann, 1892 or Oikopleura vanhoeffeni Lohmann, 1896 could be conspecific with either Appendicularia flagellum or Oikopleura chamissonis Mertens, 1830, type species of the genus Oikopleura Mertens, 1830, or with both. Whichever species are found to be synonyms, the genus name Appendicularia Chamisso has priority over Oikopleura Mertens and this is emphasised in discussions on a case put to the International Commission on Zoological Nomenclature (Case 23, 1922). At the time the decision was to table the question until more information was presented. However, the much used names Oikopleura and Oikopleuridae are used here pending an application to the Commission for Zoological Nomenclature to validate them. Further, the description of a neotype from (Bering Strait) is required to establish the identity of O. chamissonis, as the type specimen is not available.

The family is the most diverse in the class. It is represented in Australian waters by nine species of Oikopleura Mertens, 1830, and one each of Megalocercus Chun, 1887, Stegosoma Chun, 1887, Althoffia Lohmann, 1892 (all in the subfamily Oikopleurinae); and one of Bathochordaeus Chun, 1900 (in the subfamily Bathochordaeinae; Fenaux & Youngbluth 1990). The commonly occurring species are Oikopleura rufescens Fol, 1872, Oikopleura dioica Fol, 1872 and Oikopleura longicauda (Vogt, 1854). The family has been reviewed by Lohmann (1933) and Fenaux (1993), and Thompson (1945) has documented its occurrence in eastern Australian waters.