Family LEKYTHOPORIDAE Levinsen, 1909

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• Lekythoporidae Levinsen, 1909.
• Aulopocellidae Vigneaux, 1949.

Introduction

The family Lekythoporidae was introduced by Levinsen (1909) for Lekythopora and its type species, L. hystrix, described from Port Phillip Bay by MacGillivray (1883). Levinsen also included species now assigned to the genera Turritigera, Catadysis, and Orthoporidra. The family also includes the Australian genus Aulopocella and the New Zealand genera Harpago and Jugescharellina described by Gordon (1989), (Bock & Cook 2000).

The Lekythoporidae is characterised by its unusual astogeny. Colonies are principally constructed by 'reversed frontal budding' (Cook & Hayward 1983), and arise from a minute encrusting base. They are usually semi-erect, or erect and branched; minute conical colonies are later supported by rhizoids. Erect colonies usually have few branches; one species also has reticulate colonies.

Zooids are orientated with the asci and primary orifices facing towards the centre of the branch, and subsequent generations arise from frontal buds with the same orientation. All calcified walls are interior. The distal part of each zooid, and the very long peristome, are curved outward at an angle of 90º. Structures such as the ovicells, which are diverticula of the morphologically distal wall of the peristome, therefore appear at the branch surface to be topographically proximal in position. Avicularia typically occupy the edge of the peristome, communicating with a frontal septula through a long, often twisted tube in the calcification. Other avicularia arise frontally, but all structures are usually rapidly obscured, even obliterated, by the development of massive, extrazooidal calcification within a few generations of the growing tips of the branches.

Genera tend to be distinguished by orientation of zooids within the branches, which may be radial, bilaminar, or unilaterally twisted. The Lekythoporidae is overwhelmingly distributed in the Southern Hemisphere (Moyano 1985; Hayward 1993; 1995). The majority of species is cryophilic, occurring in either the Antarctic and sub-Antarctic, or at great depths in the southern oceans off South America, South Africa, and Australasia. The Recent Australian species of Catadysis and Aulopocella occur from slope depths off Victoria (Bock & Cook 2000), and Orthoporidra solida was collected by the 'Challenger' from nearly 5000 metres in the South Australian Basin. In contrast, Lekythopora and Poecilopora are known only from shallow shelf waters from southeastern Australia, and also occur in the Upper Eocene to Miocene deposits of Victoria.

The affinities of the Lekythoporidae have been regarded as closest to the Celleporidae, i.e. by Cook & Hayward (1983) and by Moyano (1985). The celleporid genus Orthoporidroides may certainly be assigned to the Celleporidae, but closely resembles some species of Lekythoporidae, except for its budding pattern, which is not reversed. On the other hand, Gordon (1989) has made a persuasive case for associating the Lekythoporidae with the other completely reverse frontally budded family, the Conescharellinidae. The characters of the ovicells and avicularia of these two families are, however, completely different. In addition, genera with 'normal' and reversed frontal budding occur within the family Lepraliellidae, i.e. Celleporaria and Sphaeropora. In fact, colonies with integrated reversed frontal budding are being described increasingly from cheilostome families. The Dhontiscidae, described by Gordon (1989) has umbonuloid frontal ontogeny and small, 'conescharelliniform' colonies. A single species of the cribrimorph genus Anaskopora, also has been found to have conescharelliniform, frontally budded colonies, whereas other species have a different astogenetic pattern (Arnold & Cook 1997).

Diagnosis

Colony principally erect, branches arising from a minute encrusting base, heavily calcified, sometimes reticulate, becoming massive. Following the earliest astogenetic stages, all budding is frontal and reversed, so that the proximal orificial sinus appears on the topographically distal side. The secondary orifice occurs at the end of a tubular peristome. Avicularia are adventitious and oral, or interzooidal. The ovicell is a globular diverticulum of the distal peristome, with a frontal area or pore, which appears to be proximal in position.

General References

Arnold, P. & Cook, P.L. 1997. Some Recent species of the genus Anaskopora Wass, 1975 (Bryozoa: Cribriomorpha) from Queensland. Memoirs of the Queensland Museum 42: 1-11

Bock, P.E. & Cook, P.L. 2000. Lekythoporidae (Bryozoa, Cheilostomata) from the Tertiary and Recent of southeastern Australia. Memorie di Scienze Geologiche 52(1): 167-174

Cook, P.L., & Hayward, P.J. 1983. Notes on the family Lekythoporidae (Bryozoa, Cheilostomata). Bulletin of the British Museum (Natural History) 45: 55-76

Gordon, D.P. 1989. The marine fauna of New Zealand: Bryozoa: Gymnolaemata (Cheilostomida Ascophorina) from the western south Island continental shelf and slope. New Zealand Oceanographic Institute Memoir 97: 1-158

Hayward, P.J. 1993. New species of cheilostomate Bryozoa from Antarctica and the Subantarctic southwest Atlantic. Journal of Natural History 27: 1409-1430

Hayward, P.J. 1995. Antarctic cheilostomatous Bryozoa. Oxford, New York, Tokyo : Oxford University Press 355 pp.

Levinsen, G.M.R. 1909. Morphological and systematic studies on the cheilostomatous Bryozoa. Copenhagen : Nationale Forfatteres Forlag 431 pp.

Macgillivray, P.H. 1883. Descriptions of new or little-known Polyzoa. Part 3. Transactions and Proceedings of the Royal Society of Victoria 19: 191-195

Moyano G., H.I. 1985. Bryozoa Lekythoporidae; Discusion general y nuevas especies de los generos Catadysis y Orthoporidra de Chile Austral y de la Antartida. Gayana Zoologia, Concepcion 49: 103-149

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