Phidolopora chakra, Boonzaaier-Davids & Florence & Gibbons, 2020

Boonzaaier-Davids, Melissa K., Florence, Wayne K. & Gibbons, Mark J., 2020, Novel taxa of Cheilostomata Bryozoa discovered in the historical backlogs of the Iziko South African Museum, Zootaxa 4820 (1), pp. 105-133 : 123-124

Phidolopora chakra n. sp.

( Fig. 9 A–F, Table 8)

zoobank.org/ C5FC26AE-A79F-4482-9E9B-197BF007998F

Material examined. Holotype: SAMC-A029097 (in ethanol), station WCD 11 (34°9.4’S, 18°16.5’E), off Kommetjie, West of Cape Peninsula , UCT Ecological Survey , dredge, depth 75 m, 24 March 1959 . Additional material: SAMC-A073471 (in ethanol), FAL 504 ; SAMC-A073516 (in ethanol), FAL 602 ; SAMC-A028898 (in ethanol), TRA 119 .

Etymology. From the Sanskrit word ‘ chakra ’, meaning wheel or disk, referring to the ooecium pseudopore reminiscent of the crown chakra symbol of the yoga tradition.

Diagnosis. Colony erect, fenestrate. Autozooids outlined by conspicuous vibices. Primary orifice with beaded anter, shallow sinus and rectangular condyles; peristome with a median groove forming a deeper pseudosinus. Oral spines absent. Adventitious avicularia of two types: suboral, small and oval; frontal, larger and triangular. Ovicell recumbent, becoming immersed later in ontogeny; ooecium with a proximal median projection bearing a pseudopore centrally.Abfrontal surface granular with marginal areolae, conspicuous vibices, and avicularia similar to those on the frontal shield.

Description. Colony erect, fenestrate. Branches (trabeculae) 0.54–0.62 mm in diameter, fusing at irregular intervals, with elongate spaces (fenestrulae) between them; fenestrulae small, oval, about 0.91 mm long by 0.40 mm wide (N T = 3). Zooids frontal shield smooth, separated by conspicuous raised lines (vibices), 1–4 marginal areolar pores proximally and/or laterally. Primary orifice with beaded anter, transversely oval with a shallow sinus and rectangular condyles; secondary orifice with deeper pseudosinus formed by the peristome bearing a median groove. Oral spines absent. Adventitious avicularia of two types: most commonly a small oval to rounded suboral avicularium with complete crossbar, about 0.05 mm long by 0.03 mm wide (N T = 6); less often a large avicularium, placed frontally on a raised cystid, occupying most of the zooidal frontal shield, with triangular, prominently hooked rostrum, about 0.15 mm long by 0.02 mm wide (N T = 2), and complete crossbar. Ovicell recumbent, widely open proximally, becoming immersed in secondary calcification during ontogeny; ooecium longer than wide, smooth, with a median projection proximally and a drop-shaped pseudopore centrally. Abfrontal surface granular with up to five marginal areolae and conspicuous vibices; one or two avicularia, same morphology as the frontal avicularia, though small oval avicularia are more common, almost exclusively situated adjacent to vibices.

(Ladav, ladav) refer to the frontal oval avicularia.

Remarks. Phidolopora is a relatively low-diverse genus, comprising on date 12 species (www. bryozoa.net, accessed 06 June 2020). This new species is confidently placed in Phidolopora based on its branching, fenestrate colony, sinuate orifice and the distinct ooecia with median convexity ( Gordon 1989). This is the first known record of Phidolopora from South Africa.

Phidolopora chakra n. sp. resembles P. avicularis MacGillivray, 1883 from southeastern Australia and New Zealand, but differs in the absence of oral spines and a median spiramen.Although the colony surface in P. chakra n. sp. exhibits distinct sutures, the original zooidal boundaries are masked by secondary calcification, which prevents accurate zooidal measurements.

Colonies of P. chakra n. sp. were attached to hard rocky substrata, and provide habitats for polychaetes and brittle stars. Colonies were collected near Kommetjie west of the Cape Peninsula and False Bay on the South Coast at 40–75 m depth.

Figures

FIGURE 9. A–F. Phidolopora chakra n. sp. (SAMC-A029097) A. Partial view of a colony fragment showing ovicelled zooids and fenestrulae (scale bar = 0.4 mm, magnified x50). B. Abfrontal view of a colony fragment showing conspicuous vibices and two types of adventitious avicularia (scale bar = 0.2 mm, magnified x75). C. Close-up of an ovicell and avicularia (scale bar = 0.1 mm, magnified x200). D. Close-up of the orifice with beaded anter and shallow sinus (scale bar = 0.05 mm, magnified x500). E. Developing ooecium (scale bar = 0.1 mm, magnified x200). F. Close-up of ovicells with median convexity and secondary calcification (scale bar = 0.1 mm, magnified x200).