Conescharellina crassa ( Tenison Woods, 1880 )

Bock, Philip E. & Cook, Patricia L., 2004, A review of Australian Conescharellinidae (Bryozoa: Cheilostomata), Memoirs of Museum Victoria 61 (2), pp. 135-182 : 145

Conescharellina crassa ( Tenison Woods, 1880)

Lunulites (Cupularia) crassa Tenison Woods, 1880: 5 , pl. 1 figs

1a–c. Bipora crassa .— Whitelegge, 1887: 343 [reprinted 1888: 18]. Conescharellina crassa .— Livingstone, 1924: 212.— Livingstone,

1925: 301, pl. 46 figs 1–5, text-fig. 1.

Description. (modified in part from Livingstone’s 1925 account). Colony a large, shallow cone, maximum diameter 10 mm, height 5 mm. Zooids arranged in quincunx. Primary orifice elongated, with a fairly narrow but rounded sinus; lateral peristomes raised, marginal peristomes prominent. Adapical pore (“special pore”) large, on the edge of the peristome, forming a tube. Root pores rounded, not lunate. Avicularia small and rounded; with a bar and one ligula; one (possibly the “vibracular pore”) placed adapically to the orifice; others minute, sometimes paired, antapical and lateral, or irregularly scattered among orifices, rounded. Antapical surface “spongy”, (inferred to have consisted of cancelli), and “solid”.

Remarks. Tenison Woods (1880) mentioned “about a dozen specimens” from Cape Three Points and Port Stephens, New South Wales. They were collected from depths of approximately 130–150 metres. Whitelegge (1887, 1888) examined these, the type specimens of C. crassa , that were then in the Macleay Museum, Sydney. He remarked on the raised lateral peristomes, the primary orifice, the subcircular avicularian mandibles and the large, antapically placed pore (inferred by Harmer (1957) to have been an avicularium) but did not mention the antapical surface or the form of root pore. Whitelegge (1887) noted that Tenison Woods’ figure was “the first published figure which exhibits the form of the true operculum-bearing aperture”. This was narrow and elongated, with a rounded sinus. Livingstone (1925) also examined the type specimens, and other colonies from New South Wales. He redescribed C. crassa , noting that some of the “vibracular pores” were “filament pores”, i.e. root pores. These were rounded, not lunate. The raised lateral peristomes obscured the orifice, with its fairly elongated, narrow sinus. The adapical pore (“special pore”) was figured on the edge of the peristome, forming a tube, very similar to the pore illustrated here in C. multiarmata ( Fig. 2D ). Livingstone (1925) was the first to suggest that “lunoecia” and “filament pores” had the same function.

Harmer (1957: 740, pl. 48 figs 1–6, text-figs 70, I, 73) described specimens from West Timor, the Arafura Sea and Holothuria Bank (north-west Australia) as C. crassa . The colonies resembled those reported from eastern Australia in size and shape, having a concave antapical surface lined by cancelli, and bordered by prominent zooids; they were, however, not solid antapically. The orifices had an elongated sinus but were arranged in quincunx, not in apparently radial series. Harmer noted that both the “vibracular pore” of Tenison Woods (1880) and the “filament pore” of Livingstone (1925) might have been avicularia. A small adapical pore (“proximal pore”) was sometimes present in his material but the circular root pores were found scattered among the orifices, not directly associated with the peristomes. Three of Harmer’s preparations have been examined (BMNH Siboga stn 59, West Timor, 390 m, 1964.3.2.8 part, and from Murray Island, Torres Strait, from Haddon, 1890.3.24.17). The latter was mentioned by Kirkpatrick (1890) who described the operculum as “broadly pyriform”. They are large colonies, ranging from 10 to12 mm in diameter but are all very worn. Only one primary orifice is clearly visible: it is wide, with a rounded sinus, unlike Tenison Woods’ figure. Otherwise, Harmer’s C. crassa resembles the original description but only examination of Tenison Woods’ type material, and comparison with that seen by Haswell from Queensland, can decide if any of them are conspecific.

Livingstone (1925: fig. 1) described ovicells in the “smallest specimen” of a group of colonies of C. crassa from north-east of Port Jackson, at 137– 146 m. These were “bean-shaped”, wider than long, flattened frontally. They appear to have had an ectooecial rim bordered by “a row of elongated pores”. The figure of the ovicells depicts these pores as minute and certainly not elongated. Curiously, Livingstone (1925: 303) noted the absence of “special pores” in the smallest colony that bore the ovicells. His illustration (pl. 46 fig. 3) leaves no doubt that the adapical pore is depicted. As its presence is a necessary part of ovicell development, his observation requires explanation. The illustration of the ovicells in C. crassa given by Livingstone (1925: Fig. 1 ) is remarkably similar to that of the ovicells of “ Batopora pulchrior ” Gordon (1989: 81 , pls 47F, G, 48A) from very deep water (914–3347 m) off New Zealand. The ovicells of B. pulchrior lack marginal pores. B. pulchrior is the type species of Ptoboroa Gordon and d’Hondt (1997) , a genus that appears to have closer links with Trochos odon than with Batopora (see below).

Although specimens of C. crassa should be recognisable from the descriptions of authors mentioned above, no colony in the collections examined here appears to be assignable to this species. Two species described here with large, relatively flattened colonies are C. cognata and C. obscura .

Figures

Figure 1. A–D, Conescharellina sp. A–C, NMV F98977, colony; direction of growth arrowed; scale=1 mm, B, detail of orifices and avicularia, scale = 500 µm, C, detail of orifice with adapical pore (arrow), scale=100 µm. D, NMV F98978, colony from antapical surface with commensal coral, scale = 1 mm. E–H, Conescharellina eburnea (Maplestone, 1909). E, BMNH 2000.2.3.33, adapical view of colony, scale=1 mm. F–H, NMV F98979. F, adapical view of colony showing root pores, scale = 500 µm. G, antapical view of colony with small, central and paired marginal peristomial avicularia (arrow), scale=500 µm. H, detail of orifices and avicularia, adapical pore arrowed, scale= 100µm.

Figure 2. A–B, Conescharellina biarmata (Maplestone, 1909). NMV F98980. A, lateral view of colony, growth direction arrowed, scale=1 mm. B, detail of orifices with adapical pore, avicularia and slit-like frontal septular pores, scale= 100 µm. C–D, Conescharellina multiarmata Maplestone, NMV F98981. C, Lateral view of colony, growth direction arrowed, scale=500 µm, D, detail of orifices from slightly antapical view, showing tubular adapical pores, avicularia and minute frontal septular pores, scale = 200 µm. E–F, Conescharellina multiarmata (Maplestone, 1909). E, NMV F98983, orifices and avicularia; note pattern of septular pores, scale= 200 µm. F, NMV F98982, Antapical view of colony showing small solitary coral. Note paired, marginal peristomial avicularia, scale= 500 µm.