Reteporella ilala, 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 : 125-128

Reteporella ilala n. sp.

( Fig. 10 A–E, 11A–D, Table 9)

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Material examined. Holotype: SAMC-A028986 (in ethanol), station AFR273 A31624 (33°48’24”S, 25°56’48”E), Algoa Bay , Southeast Coast, South Africa, South Coast Demersal Survey, trawl, depth 45 m, 21April 2011 . Additional material: SAMC-A028945 (dry), AFR273 A31605 ; SAMC-A029047 (dry), AFR273 A31624 ; SAMC-A073533 (in ethanol) , SAMC-A077209 (in ethanol) , SAMC-A077582 (in ethanol), FAL 42 ; SAMC-A073438 (in ethanol), FAL 330 ; SAMC-A077624 (in ethanol), FAL 475 ; SAMC-A073464 (in ethanol), FAL 504 ; SAMC-A077496 (in ethanol) , SAMC-A077526 (in ethanol), FAL 576 ; SAMC-A077460 (in ethanol), FAL 603 ; SAMC-A028899 (in ethanol), TRA 31 ; SAMC-A029069 (in ethanol) , SAMC-A029168 (in ethanol), WCD 6 ; SAMC-A029107 (in ethanol), WCD 11 ; SAMC-A029149 (dry) , SAMC-A029150 (dry), WCD 32 ; SAMC-A029119 (in ethanol), WCD 159. Additional comparative material: Reteporella clancularia , SAMC-A026304 (holotype), station SM 23 (27°44.4’S, 32°42.8’E), off iSimangaliso Park , East Coast, South Africa , RV Meiring Naude Survey, heavy dredge, depth 400450 m, 26 May 1975. Reteporella dinotorhynchus , SAMC-A026305 (holotype), same station as above .

Etymology. From the isiZulu word ‘ ilala ’ indicating the traditional hand woven baskets of the Zulu people, made with the native Lala palm tree. The shape of the baskets resembles the shape of the colony of this species.

Diagnosis. Colony erect, rigid, deep cup-shaped. Autozooids diamond-shaped, granular. Primary orifice, elliptical, obscured by the peristome; anter beaded, condyles triangular. Oral spines absent. Peristome embedding the suboral avicularium, sometimes forming a U-shaped pseudosinus or pseudospiramen. Avicularia on the frontal either small and rounded or larger and elliptical; large elliptical avicularia around edges of fenestrulae. Ovicell inconspicuous; ooecium with broad frontal fissure and short labellum. Abfrontal surface with conspicuous vibices and numerous oval avicularia.

Description. Colony erect, rigid, deep cup-shaped. Branches (trabeculae) about 1.18 mm in diameter, fusing at irregular intervals forming elongate spaces (fenestrulae) between them; fenestrulae irregularly oval, about 1.05 mm long by 0.57 mm wide (N T = 3). Autozooids diamond-shaped at growing edge, slightly convex, about 0.60 mm long by 0.57 mm wide, separated by indistinct sutures. Frontal calcification finely granular, with conspicuous marginal pores, 4–6 marginal pores in autozooids at the growing edge; frontal pores sometimes present. Primary orifice wider than long, elliptical, obscured in early ontogeny by a deep proximal peristome, proximal border nearly straight or shallowly concave, anter beaded, condyles triangular but only visible in zooids at the growing edge. Oral spines absent. Proximal peristome deep, embedding the suboral avicularium, forming a U-shaped pseudosinus, which sometimes closes over to form an asymmetric pseudospiramen. Suboral avicularium with a bluntly triangular rostrum and complete crossbar. More than one type of avicularia sporadically develop on the frontal; either short, rounded, about 0.06 mm long by 0.05 mm wide, with semicircular mandible, calcified palate reduced to less than half rostral length, and oval foramen; or elliptical, about 0.11 mm long by 0.07 mm wide, with semi-elliptical mandible, calcified palate occupying more than half rostral length, and oval foramen; all frontal avicularia have raised, sometimes swollen margins and thick, centrally placed crossbars. Larger elliptical avicularia with slightly spatulate rostrum, about 0.30 mm long by 0.14 mm wide, scattered on the frontal and around edges of fenestrulae, with raised margin, and thick crossbar placed at about one third of the total length of the avicularium; calcified palate occupying more than half rostral length, triangular to funnel-shaped foramen. All types of avicularia are randomly oriented. Ovicell inconspicuous; ooecia totally covered by thick secondary calcification formed by 2–3 distal/distolateral zooids indicated by corresponding number of sutures, and with a broad frontal fissure (non-calcified area) and short labellum. Abfrontal surface of colony with thick vibices and numerous oval avicularia; larger elliptical avicularia may occur along the inner edges of the fenestrulae. Mural septula present.

Remarks. Most of the material available comprises fragmented or young colonies, except for one colony (SAMC-A028986) that was large and deep cup-shaped, about 10 cm in height ( Fig. 10A ). This species clearly belongs to Reteporella in having alternating series of autozooids, a primary orifice elliptical with concave proximal border and condyles, a well-developed peristome that obscures the orifice and forms a pseudosinus. It is distinguished by all congeners by its colony shape and the number, shape and variety of frontal adventitious avicularia.

Reteporella ilala n. sp. was found attached to hard rocky substrata west of the Cape Peninsula near Kommetjie to False Bay and Arniston on the South Coast at 22–102 m depth.

Figures

FIGURE 10. A–E. Reteporella ilala n. sp. A. View of the colony (SAMC-A029168) (scale bar = 10 mm). B. Autozooids surrounding the fenestrula with avicularia along the margins (SAMC-A029107) (scale bar = 0.4 mm, magnified x50). C. Abfrontal view (SAMC-A028899) (scale bar = 0.4 mm, magnified x35). D. Group of autozooids at the growing edge (SAMC-A029107) (scale bar = 0.2 mm, magnified x100). E. Autozooids and avicularia (SAMC-A029107) (scale bar = 0.2 mm, magnified x75).