Saevitella peristomata ( Waters, 1899 ) Waters, 1899

Berning, Björn, 2012, Taxonomic notes on some Cheilostomata (Bryozoa) from Madeira, Zootaxa 3236, pp. 36-54 : 44-46

Saevitella peristomata ( Waters, 1899) n. comb.

( Figs 13–18 , Table 3)

‘L.[epralia] mangnevilla Aud.’: Busk 1860: 284, pl. 31, fig. 5; non Cellepora mangnevillana Lamouroux, 1816 .? Lepralia pallasiana: Hincks 1880: 77 , pl. 10, fig. 3; non Eschara pallasiana Moll, 1803 . Lepralia peristomata Waters, 1899: 10 , pl. 3, fig. 20; Norman 1909: 305.

? Cosciniopsis peristomata: Cook 1968: 182 .

Material examined. Lectotype: MMF 42043a (here designated), the only bleached specimen on slide; material from Madeira, collected by J. Y. Johnson from a fish basket trap in 1880 (no further information provided as to the exact location or depth). Paralectotypes: MMF 42043b–e, the remaining unbleached specimens on the same slide as holotype; judging by residual glue in the slide cavity, one specimen of the original suite is missing.

Description. Colony encrusting, unilaminar, multiserial. Zooids subhexagonal, broadest at about mid-distance, separated by shallow grooves or indistinct sutures. Frontal shield only slightly convex, entirely and regularly perforated by numerous round pseudopores separated by nodular ridges. Primary orifice elliptical with a fairly straight proximal margin, slightly longer than wide, broadest in distal third, condyles indistinct in frontal view, pointing downwards, demarcating proximal fourth of total orifice length, visible in an oblique view only; operculum with a pair of small frontal tubercles situated in the proximal fourth; flared peristome entirely surrounding orifice, the interior smoothly calcified with longitudinal striations, outline variable, from oval with relatively straight or wavy lateral margins to 8-shaped with central indentations almost meeting in centre; orifice in ovicellate zooids only slightly dimorphic, distal margin of peristome formed by proximal ooecial rim and is rather vertically oriented and lower than lateral peristomial margins; oral spines absent.

ZL ZW OL OW OvL OvW mean 630 419 149 125 171 279 SD 43 60 11 7 16 23 min. 556 286 121 108 153 242 max. 707 509 166 134 200 318 n 19 19 16 16 14 14

Ovicell subimmersed, endooecium hemispherical, fused onto distal zooecial margin of maternal zooid, broader than long, largely immersed by secondary calcification of distal zooid during ontogeny, surface similar to frontal shield but with smaller and rather elongated pseudopores and relatively thicker and steeper interjacent ridges; proximal ooecial margin concave, the slightly raised ridge fused with lateral peristomial walls of maternal zooid; closed by operculum.

Avicularia absent.

Ancestrula not observed.

Remarks. The colonies here designated as (para-) lectotypes were given to Waters for identification by James Yates Johnson and were subsequently returned to the MMF. As Waters (1899) figured only an operculum when introducing Lepralia peristomata , the figured specimen cannot be determined. Hence, I chose the colony in which zooecial and ooecial characters were best displayed.

Saevitella peristomata is morphologically very similar to the type species S. inermis Bobies, 1956 . Differences are found in orifice shape, which is slightly broader than long in S. inermis , and the peristome, which is rather round or transversely elliptical in outline and not as flared as in S. peristomata .

Waters' (1899) and Norman's (1909) view that the Madeiran specimens identified as Lepralia mangnevilla [sic] by Busk (1860) are conspecific with S. peristomata is upheld here. The species described and figured as Lepralia pallasiana [= Cryptosula pallasiana ( Moll, 1803) ] by Hincks (1880) is also very similar and could be conspecific as well.

Saevitella peristomata was sampled around Madeira at depths of 25– 130 m. It was subsequently also reported from the Cape Verde and Canary Islands by Waters (1918: 21) and (as Cosciniopsis peristomata ) by Cook (1968: 182), Arístegui & Cruz (1986: 166), and Arístegui (1987). However, these records need to be checked for conspecificity.

Figures

FIGURES 13 – 18. Saevitella peristomata (Waters, 1899) n. comb. 13, surface of mature colony with ovicellate zooids (lectotype, MMF 42043 a). 14, primary orifice, note the immersed, downward pointing condyle (arrow) which is visible only in lateral view (lectotype, MMF 42043 a). 15, two ovicellate zooids (lectotype, MMF 42043 a). 16, view into an ooecium; the upper part of the endooecium is fused onto the distal zooecial margin of the maternal zooid, while a basal wall of the brooding cavity is lacking, suggesting that incubation is partly internal (lectotype, MMF 42043 a). 17, autozooids in which the peristome is eight-shaped and the central indentations nearly meet in the centre (paralectotype, MMF 42043 c). 18, distal view into the same ooecium as in Fig. 16, showing the bulging distal zooecial wall and endooecium, and one condyle (arrow); note that the distal margin of the primary orifice is absent, suggesting that the ovicell is closed by the operculum (lectotype, MMF 42043 a; photo courtesy of A. Ostrovsky). Scale bars: Fig. 13 = 200 µm; Figs 14, 16 = 40 µm; Figs 15, 17, 18 = 100 µm.