Family MARGARETTIDAE Harmer, 1957

Museums

Regional Maps

• Margarettidae Harmer, 1957.
• Tubucellariidae Busk, 1884.

Taxonomic Decision for Synonymy

• Harmer, S.F. 1957. The Polyzoa of the Siboga Expedition. Part 4. Cheilostomata Ascophora II. Siboga-Expéditie Report 28D: 641-1147

Introduction

The family Margarettidae was introduced by Harmer (1957) for species previous referred to the genus Tubucellaria. The family included one genus, Margaretta Gray (1843). Colonies are erect, branched and nodal, attached by cuticular rhizoids arising from an erect ancestrula. Each internode is cylindrical and may be slightly curved, and is composed of from 2 to 8 alternating series of long, tubular zooids. Each node is formed by 2 to 3 cuticular tubes, arising from a calcified 'basis rami' on the frontal side of a zooid at the distal end of the previous internode. The frontal calcification of the autozooids is profusely porous, and secondary calcification obscures the outlines of the zooids. An ascopore opens proximally to the secondary orifice, which is at the end of a tubular peristome. Spines and avicularia are absent from all species. The ovicell is immersed in the distal wall of the peristome, and brooding zooids are marked by inflated, prominent, often curved peristomes.

Margaretta has a world-wide, warm-water range from the shallow shelf. The commonest Australian species is M. hirsuta, which was described from Victoria in 1880 by MacGillivray (Bock 1982). M. hirsuta is marked by the presence of a pair of very long setiform cuticular appendages which arise from the sides of the secondary orifice, and give the colony a hairy appearance (cf. Cellaria pilosa). M. hirsuta also occurs as a Pliocene fossil from Victoria (Stach 1935). In addition, three other species have been reported from Australia. M. watersi, M. tenuis, and M. triplex all occur from Torres Strait and the Queensland coast (Harmer 1957; Ryland & Hayward 1992). A record of Tubucellaria cereoides by MacGillivray (1885) belongs to M. watersi (Harmer 1957).

Diagnosis

Colony erect, nodal, well calcified, arising from an erect ancestrula and anchored by numerous rhizoids. Internodes often long and curved, formed by whorls of zooids with porous, lepralioid frontal shields, and terminal orifice with tubular peristome. Ascopore present. Avicularia absent. Brooding in peristomial ovicells with elongated peristomes.

General References

Bock, P.E. 1982. Bryozoans (Phylum Bryozoa). pp. 319-394 in Shepherd, S.A. & Thomas, I.M. (eds). Marine Invertebrates of Southern Australia. Handbook of the Flora and Fauna of South Australia Adelaide : Government Printer Part 1 491 pp.

Gray, J.E. 1843. Additional radiated animals and Annelides. pp. 292-295 in Dieffenbach, E. (ed.). Travels in New Zealand: with contributions to the geography, geology, botany and natural history of that country. London : John Murray Vol. 2.

Harmer, S.F. 1957. The Polyzoa of the Siboga Expedition. Part 4. Cheilostomata Ascophora II. Siboga-Expéditie Report 28D: 641-1147

Macgillivray, P.H. 1880. Polyzoa. 27-52, pls 45-49 in McCoy, F. (ed.). Prodromus of the Zoology of Victoria Decade 5. Melbourne : George Robertson Vol. 5.

Macgillivray, P.H. 1885. Polyzoa. 13-31, pls 94-99 in McCoy, F. (ed.). Prodromus of the Zoology of Victoria Decade 10. Melbourne : George Robertson.

Ryland, J.S. & Hayward, P.J. 1992. Bryozoa from Heron Island, Great Barrier Reef. Memoirs of the Queensland Museum 32(1): 223-301

Stach, L.W. 1935. Victorian Lower Pliocene Bryozoa, pt. 1. Proceedings of the Royal Society of Victoria 47(2): 338-351

History of changes