Family BICELLARIELLIDAE Levinsen, 1909

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Family BICELLARIELLIDAE Levinsen, 1909

Compiler and date details

July 2001 - Dr Philip Bock

Introduction

The family Bicellariellidae, as first introduced by Levinsen (1909) included Bugula and Beania among its genera. Bassler (1953) excluded these and placed them in the families Bugulidae and Beaniidae respectively. He also used the emended name Bicellariellidae for the family, which included Klugella (now assigned to the Bugulidae), and Petalostegus, now assigned to the Petalostegidae.

As noted in the section on Bugulidae, the Bicellariellidae has often been merged in the Bugulidae in the past. However, genera with 'turbinate' zooids have tended to be separated. The turbinate zooid has a long, often tubular, proximal gymnocyst, constricted and then unilaterally expanded distally around the frontal membrane. Numerous oral, distal and marginal spines, sometimes jointed, arise from the margin of the frontal area, which may be orientated almost at right-angles to the proximal gymnocyst. Avicularia are pedunculate, but may be considerably modified from the bird's-head type. Ovicells are prominent and usually open at an angle to the operculum.

The family is represented in Australia by one species of Bicellariella (MacGillivray, 1881), four species of Cornucopina (Levinsen 1909), and three of Dimetopia (Busk 1852; MacGillivray 1880). In addition, eleven species of Cornucopina have been described from the southern oceans, the Antarctic and subantarctic by Hastings (1943) and reviewed by Hayward (1995).

Bicellariella ciliata was originally described from Europe by Linnaeus (1758), and has been reported from many other areas, including Port Phillip Heads (MacGillivray, 1881). The local material appears very similar to published descriptions (eg Ryland & Hayward 1977). A specific associated nudibranch, Janolus hyalinus, presumably a predator on the bryozoan, is reported associated with this species from Australia as well as from England (Miller & Willan 1986).

Cornucopina grandis Busk (1852) has large, densely branched, almost globular, pink colonies, reaching 100 mm in height and breadth (Bock 1982). It occurs in southern Australia from depths of 20 to greater than 1200 m. The zooids have very long, curved spines (Harmer, 1926). Hastings (1943) gave details of the early astogeny, ovicells and avicularia of some southern ocean species. Some avicularia are extremely long (more than 3 mm), and spine-like, with the distal end flaring like a bugle. Similar avicularia occur in Nordgaardia. Colonies of Cornucopina tuba are host for Aetea curta Jullien(McKinney, 1988).

Dimetopia has funnel-shaped zooids, with symmetrically placed ovicells. Avicularia are absent. Two species, D. spicata and D. cornuta were described by Busk (1852); however, D. spicata is the junior synonym of D. barbata (Lamouroux 1816) (Stach 1937). A third species, D. hirta, was described by MacGillivray (1886); additional descriptions with illustrations were made by MacGillivray (1880, 1889). All were from fairly shallow water in Bass Strait, but additional material has been collected at depths up to 300 m.

An undescribed 'bicellariellid' was reported from the Early Eocene of the Indian Ocean by Labracherie (1975). Single separated zooids collected from the Miocene of Victoria have been identified as Dimetopia species (unpublished data).

Diagnosis

Colony erect, bushy, profusely branched, unjointed, weakly calcified, attached by rhizoids. Zooids turbinate, with long, tubular gymnocyst and rounded, terminal opesia, surrounded by long, jointed spines. Avicularia small, pedunculate. Ovicells small, independent and hyperstomial, with a membranous outer layer.