Calloporina mariae, Berning, Björn, 2012

Berning, Björn, 2012, Taxonomic notes on some Cheilostomata (Bryozoa) from Madeira, Zootaxa 3236, pp. 36-54 : 40-42

Calloporina mariae n. sp.

( Figs 6–11 , Table 2)

Microporella decorata: Hincks 1880: 74 ; Norman 1909: 297, pl. 39, figs 2, 3.

Material examined. Holotype: NHMUK 2011.9.1.1. Paratypes: NHMUK 2011.9.1.2, NHMUK 2011.9.1.3. Other: NHMUK 1911.10.1.1247. All specimens from the Norman collection, Madeira, 70 m (according to Norman 1909) or 130 m (according to the specimen label). Holotype and paratypes were selected and given new numbers from the original suite of specimens collected by Norman ( NHMUK 1911.10.1.1247), whereas the remaining specimens are too poorly preserved and/or too small to serve as types, keeping the original registration number.

Diagnosis. Calloporina mariae n. sp. differs from the only other northern Atlantic and Mediterranean species, the Miocene to supposedly Recent Calloporina decorata ( Reuss, 1847) , in having of nine instead of six oral spines, in a proximal ooecial margin that terminates at the distal orifice margin, and in having avicularia with an evenly narrowing rostrum.

ZL ZW OL OW OvL OvW AL AW mean 611 471 123 114 295 348 252 65 SD 46 42 7 6 25 29 53 12 min. 542 381 111 103 245 280 174 45 max. 709 544 140 125 344 415 348 85 n 20 20 20 20 20 20 20 20

Etymology. I dedicate this species to my wife, María Gómez-Berning.

Description. Colony encrusting unilaminar, multiserial. Zooids subhexagonal with a more or less rounded distal margin, separated by deep grooves, vertical walls well-developed with 3–6 large subrounded communication pores per neighbouring zooid. Frontal wall slightly convex, imperforate in the proximal centre, with a single row of areolar septular pores proximally and up to 3 rows of marginal areolar pores towards the orifice, interspaced with thickened struts, additional pseudopores associated with frontal avicularia and between ascopore and orifice; ascopore round, transversely elliptical or of irregular outline, encircled by a sloping rim of smooth calcification, separated from proximal orificial border by a distance equivalent to length of orifice; frontal calcification rugose and umbonate, usually forming a diagonal ridge from the orifice around the ascopore and towards the proximal zooid margin. Orifice transversely D-shaped, about as long as wide, proximal margin straight and finely corrugated, increasing in thickness towards the corners, these shoulders often with one or two low blunt denticles; orifice usually surrounded by 9 thick long spines in autozooids (occasionally 8 and commonly 10 in the periancestrular region), and 6 in ovicellate zooids.

Ovicell globose, hyperstomial, ooecium thickly calcified, formed by distal zooid and partly immersed in frontal shield of distal zooid, wider than long; outermost distolateral ooecium covered by secondary calcification of the rugose surface of the distal frontal shield, which is marked off from the characteristic horseshoe-shaped distolateral band (c. 60 µm width) of exposed ectooecium by a distinct vertical edge; ectooecial surface initially entirely smooth but quickly becoming shallowly pitted; central area of irregular endooecial calcification covered by membranous part of entooecium in living zooids, producing a centrally or proximally positioned umbonate apex or ridge, endooecium again demarcated from calcified part of ectooecium by a distinct broad edge and a row of irregular pseudopores leading into the intermediate coelomic lumen, each proximolateral corner with another distinct pore; ovicell opening suborbicular, terminating at the distal edge of, and opening above, the primary orifice.

Avicularia adventitious, single or occasionally paired in ovicellate zooids, rarely absent, originating from marginal pores at or proximal to ascopore, long, slender and of variable length, always terminating at lateral oral spines and directed distally; rostrum very elongate triangular, evenly narrowing towards pointed tip, more or less incurved and downcurved distally; distal uncalcified area subrounded or subtriangular, proximal area semicircular; crossbar complete, without columella.

Ancestrula tatiform (c. 420 x 290 μm) with well-developed proximal gymnocyst, a narrow proximolateral cryptocyst, and 13–14 spines encircling opesia that occupies slightly more than distal half of ancestrula; first autozooid budded distally, then two second-generation zooids follow distolaterally.

Remarks. Norman (1909) mentioned the presence of eight spines in the material he described from Madeira, although in Hincks' (1880) material and in the present specimens, which are also from Norman's collection (albeit from a deeper sample), there are nine and occasionally even ten spines. The number of spines in Calloporina mariae n. sp. may thus vary between colonies and/or environments. The material in the collections of Hincks and Norman was taken from depths between 55– 130 m.

The new species is clearly distinguishable from both the fossil genotype and the modern specimens recorded from the Mediterranean Sea. Specimens observed with SEM of fossil Calloporina decorata ( Reuss, 1847) of a similar age and location as the lectotype ( Schmid et al. 2001; pers. observ.) show that 1) there are usually six oral spines in autozooids; 2) the proximolateral margins of the ooecium usually reach the lateral orificial rim, producing an opening that could have been closed by the operculum (see below, and the remarks on the generic diagnosis above); and 3) the avicularian rostrum has lateral edges that are largely parallel or even waisted at about mid distance, while tapering only in the distal part ( Fig. 12 ). However, it is difficult to comment on the relationships between the fossil C. decorata and its presumed modern representatives from the Mediterranean Sea as SEM images of Recent specimens are not available. Zabala & Maluquer (1988: 137, fig. 322) and Canu & Bassler (1930: 47, pl. 2, fig. 13) figured two spines in ovicellate zooids, whereas there are four in the fossil, and the avicularia are not waisted but, as in C. mariae n. sp., evenly narrowed distally. In the specimen described and figured by Canu & Bassler (1925: 38; 1928: pl. 4, fig. 5) the avicularia are not directed distally but are aligned with the distolateral zooecial margins, i.e. they point distomedially. These differences suggest that there are more Calloporina species, possibly none of them conspecific with fossil C. decorata , present along the Atlanto-Mediterranean shores of Africa and Europe. Calloporina mariae n. sp. has hitherto only been recorded from Madeira.

Figures

FIGURE 12. Calloporina decorata (Reuss, 1847), NHMW 2000 z 0180 / 0000 c, St. Margarethen, Austria, upper Badenian (Middle Miocene). Note the presence of six oral spines, and the comparatively broad and waisted avicularian rostra, all of which were, however, previously damaged and subsequently replaced by a smaller, second-generation avicularium. Scale bar: 200 µm.

FIGURES 6 – 11. Calloporina mariae n. sp. 6, autozooids and ovicellate zooids (paratype, NHMUK 2011.9.1.3). 7, primary orifice; note the corrugated proximal margin (paratype, NHMUK 2011.9.1.3). 8, ovicellate zooids (holotype, NHMUK 2011.9.1.1). 9, ovicell with exposed pitted ectooecium (paratype, NHMUK 2011.9.1.3). 10, zooids at the colony margin with a sequence of ooecium formation (paratype, NHMUK 2011.9.1.3). 11, ancestrula and early astogenetic zooids (on same substratum as holotype but different colony). Scale bars: Fig. 6 = 100 µm; Figs 7, 9 = 40 µm; Figs 8, 10, 11 = 200 µm.