Family ANNECTOCYMIDAE Hayward & Ryland, 1985

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Introduction

The family was introduced by Hayward & Ryland (1985) to replace the poorly defined and perhaps spurious Diaperoeciidae Canu (1918). It originally embraced two genera, Annectocyma Hayward & Ryland (1985) and Entalophoroecia Harmelin (1976), but systematic review of cyclostome faunas will probably result in other genera being assigned to it. Colonies of Annectocyma and Entalophoroecia are notoriously plastic; both commence as encrusting, narrow lobes which characteristically develop erect, branching, clavate growths, often intergrown with hydroids and other erect bryozoans.

The ancestrula gives rise to a narrowly lobed, dichotomously branching, encrusting colony, which may develop erect, cylindrical to clavate stems, also branching, with autozooids disposed in whorls. Autozooids are budded in alternating longitudinal series, the erect peristomes quincuncially arranged, or forming irregular transverse rows. Pseudopores are prominent, and internal hooked spines may be seen in the interior of the skeleton. The gonozooid is elongate, pyriform, often at a dichotomy in encrusting growth forms, or forming the clavate end of an erect branch. The gonozooid is not lobed laterally; its ooeciostome is situated distally or medially, and has a its flared aperture. Encrusting colonies of Entalophoroecia spread by regular dichotomous division of their lobes. Annectocyma, additionally, develops adventitious branches, the first being produced by the ancestrula after the establishment of the primary buds.

All species referred to Diaperoecia Canu need to be re-examined before they can be confidently assigned to a genus within the Annectocymidae. Pustulopora australis Busk, referred to Diaperoecia by Bock (1982), appears to belong to the family, and almost certainly other Australian species previously assigned to Entalophora, Pustulopora, or Diastopora will prove to be annectocymids. Harmelin (in litt. 9.9.1989 to the late Shane Parker) referred D. australis to Annectocyma after examination of specimens. A. australis is 'fairly common in Bass Strait', and the brown colonies are 'usually found encircling stems of hydroid colonies or flexible bryozoan colonies' (Bock, 1982).

Bryozoans from existing collections which appear to belong to this family are common at shallow subtidal depths. However, unidentified material with similar colony forms has been collected to depths as great as 800 m.

Diagnosis

Colony well calcified, encrusting with dichotomously branched lobes, which may give rise to erect, cylindrical, branching stems, with whorls of autozooids. Zooid walls with prominent pseudopores, peristomes erect, forming transverse rows. The gonozooid is elongated, occurring at bifurcations of zooid rows, or forming a clavate end of an erect branch. Ooeciostome distal or medial, with a flared aperture.

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.

Canu, F. 1918. Les ovicelles des Bryozoaires cyclostomes. Étude sur quelques familles nouvelles et anciennes. Bulletin de la Société Géologique de France 4 16: 324-335

Harmelin, J.-G. 1976. Le sous-ordre des Tubuliporina (Bryozoaires Cyclostomes) en Méditerranée. Écologie et systematique. Mémoires de l'Institut Océanographique, Monaco 10: 1-326

Hayward, P.J. & Ryland, J.S. 1985. Systematic notes on some British Cyclostomata (Bryozoa). Journal of Natural History 19: 1073-1078

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