Family CONESCHARELLINIDAE Levinsen, 1909
Compiler and date details
May 2010 - Liz Greaves
July 2001 - Dr Philip Bock
- Conescharellinidae Levinsen, 1909.
- Biporidae Gregory, 1893.
Introduction
Gregory (1893) introduced the subfamily Biporinae for ascophorans with an orificial sinus or with an ascopore ('trypa'), with patelliform colonies and regularly arranged avicularia. Levinsen (1909) introduced the Conescharellinidae for Conescharellina and Flabellopora, originally described from Philippines and China Sea respectively by d'Orbigny (1852). Bassler (1953) added Bipora (including Zeuglopora), Trochosodon, and Crucescharellina to the Conescharellinidae. Although Biporidae has at times been recognised as having seniority, Bock & Cook (2004) discuss the history of the relationships and conclude that Conescharellinidae has been in common usage and should thus be considered the senior synonym. Six of the seven genera occur in Australia (Bock & Cook, 2004).
Many past attempts to explain the astogeny of the colonies, from Tenison Woods's (1880) first descriptions, to the investigations of Whitelegge (1887), Maplestone (1909; 1910), Silén (1947) and Harmer (1957), lacked full understanding of frontal budding (Banta 1972), and reversed frontal budding (Cook & Lagaaij 1976).
Colonies are formed entirely by reversed frontal budding. The ancestrula is part of a binary complex including a rhizoid. Autozooids are orientated with the proximal orificial sinus and the ascus directed antapically, away from the ancestrula. All calcified zooid walls are frontal and interior, and alternating zones of buds derived from frontal septulae increase rapidly in size with astogeny. Kenozooids (lunoecia) produce further rhizoids as the colony grows, usually near the earliest astogenetic region. Avicularia are interzooidal and form distinctive patterns. Ovicells are known in few species; they are extremely delicate and sometimes asymmetrical (Harmer 1957).
Colonies are minute, and therefore not often recorded. Conescharellina rarely exceeds 8 mm in diameter, whereas the leaf-like lobes of Flabellopora attain a width of 30 mm, but usually are much smaller. Genera are characterised by the orientation of the zooids in the colony structure. Conescharellina and Trochosodon are radially arranged in conical or lens-shaped colonies. In Zeuglopora and Flabellopora, the cone is laterally compressed, forming a superficially bilaminar structure. Colonies of Bipora show an intermediate condition and are fan-shaped. In Crucescharellina the cone is vertically compressed, the zooids occurring in branched, star-shaped groups.
At maturity, kenozooids and extrazooidal calcification covers the earliest astogenetic regions. In Conescharellina, the antapical budding region also develops a cover of extrazooidal porous calcifications called cancelli.
Recent Conescharellinidae have an overwhelmingly Indo-west Pacific, sometimes abyssal, distribution, always in fine, soft sediments. Colonies are anchored by rhizoids or within the upper layers, and may have an entirely interstitial life cycle, even the larvae spending their short motile existence within the sediment (Cook & Chimonides 1985). All the Australian genera have been reported from shelf depths in New South Wales, and several also from Queensland. Conescharellina has a very wide Australian distribution and is also known from Victorian Miocene deposits. The earliest fossil record is from the early Eocene of France (Taylor 1993).
General References
Banta, W.C. 1972. The body wall of cheilostome Bryozoa, V. Frontal budding in Schizoporella unicornis floridana. Marine Biology, Berlin 14: 63-71
Bock, P.E., Cook, P.L. 2004. A review of Australian Conescharellinidae (Bryozoa: Cheilostomata). Memoirs of Museum Victoria 61(2): 135-182
Cook, P.L., & Lagaaij, R. 1976. Some Tertiary and Recent conescharelliniform Bryozoa. Bulletin of the British Museum (Natural History) 29: 317-376
Cook, P.L. & Chimonides, P.J. 1985. Larval settlement and early astogeny of Parmularia (Cheilostomata). pp. 71-78 in Nielsen, C. & Larwood, G.P. (eds). Bryozoa: Ordovician to Recent. Fredensborg : Olsen & Olsen.
Gregory, J.W. 1893. On the British Palaeogene Bryozoa. Transactions of the Zoological Society of London 13: 219-279
Harmer, S.F. 1957. The Polyzoa of the Siboga Expedition. Part 4. Cheilostomata Ascophora II. Siboga-Expéditie Report 28D: 641-1147
Maplestone, C.M. 1909. The results of deep-sea investigations in the Tasman Sea, 1. The expedition of HMCS "Miner", no. 5: The Polyzoa. Records of the Australian Museum 7: 267-273
Maplestone, C.M. 1910. On the growth and habits of the Biporae. Transactions of the Royal Society of Victoria 23: 37073
Silén, L. 1947. Conescharellinidae (Bryozoa Gymnolaemata) collected by Prof. Dr. Sixten Bock's expedition to Japan and the Bonin Islands 1914. Arkiv för Zoologi 39A: 1-59
Taylor, P.D. 1993. Bryozoa. pp. 465-489 in Benton, M.J. (ed.). The Fossil Record 2. London & New York : Chapman & Hall 845 pp.
Tenison-Woods, J.E. 1880. On some Recent and fossil species of Australian Selenariadae (Polyzoa). Transactions of the Philosophical Society of Adelaide 1880: 1-12
Whitelegge, T. 1887. Notes on some Australian Polyzoa. Proceedings of the Linnean Society of New South Wales 2 2(2): 337-347
History of changes
| Published | As part of group | Action Date | Action Type | Compiler(s) |
|---|---|---|---|---|
| 25-Mar-2014 | BRYOZOA Ehrenberg, 1831 | 25-Mar-2014 | MODIFIED | Dr Robin Wilson (NMV) Elizabeth Greaves (NMV) |
| 12-Feb-2010 | (import) |