Calvetopora inflata ( Calvet, 1906 ) Berning & Harmelin & Bader & Cibio, 2017

Berning, Björn, Harmelin, Jean-Georges & Bader, Beate, 2017, New Cheilostomata (Bryozoa) from NE Atlantic seamounts, islands, and the continental slope: evidence for deep-sea endemism, European Journal of Taxonomy 347, pp. 1-51 : 38-40

Calvetopora inflata ( Calvet, 1906) gen. et comb. nov.

Fig. 13 A–F, Table 13

Lepralia inflata Calvet, 1906: 159 .

Lepralia inflata – Calvet 1907: 411, pl. 27, fig. 10.

Material examined

Holotype (by monotypy)

GULF OF CÁDIZ: 1 colony on L. pertusa, Stn 24 ( MNHN-IB-2008-2470 ).

Description

Colony encrusting, unilaminar, multiserial, forming small patches ( Fig. 13A ). Zooids large, particularly broad, polygonal, separated by deep grooves ( Fig. 13 B–C); lateral walls relatively reduced, becoming slightly more extensive distally, communication via one or two basal pore chambers per neighbouring zooid ( Fig. 13E ), outer surface gymnocystal, pore windows very elongate, surrounded by cryptocystal calcification with a reticulate surface, distal pore enlarged. Frontal shield entirely made of cryptocystaltype calcification, convex, rising distally to form a very broad bulge suborally that drops vertically towards orifice, marginally perforated by a row of variably sized pores plus a few scattered ones in central part ( Fig. 13 D–E); surface structure a distinct honey-comb pattern of steep ridges bounding deep depressions, covering entire frontal including avicularian cystid and suboral bulge.

Orifice D-shaped, wider than long, proximal margin straight; condyles practically absent, operculum hinged on proximal tips of lateral orifice rim; seven spines in non-maternal zooids, six in ovicellate ones with a gap between distal pair.

Ooecium kenozooidal, budded from distal septular pore of maternal zooid ( Fig. 13E ), hyperstomial, barely resting on frontal shield of distal zooid ( Fig. 13C ), globular, broader than long, with an extremely short peristome wedged in between distal pair of oral spines, terminating at distal orifice margin; ectooecium almost entirely membranous except for its very base; endooecium imperforate, surface structure as that of frontal shield ( Fig. 13E ); ooecial aperture suborbicular ( Fig. 13D ), not closed by operculum.

Adventitious avicularia paired, oval, widest in distal third, situated at distolateral zooid margin lateral to proximal half of orifice on a slightly raised cystid that extends laterally beyond zooidal boundary ( Fig. 13C, E ); rostrum semi-elliptical, directing laterally or distolaterally, positioned at an acute angle to frontal plane, distal uncalcified area suborbicular; mandible hinged on a pair of thin triangular condyles that usually do not fuse at centre, proximal uncalcified area semicircular ( Fig. 13F ).

Ancestrula tatiform, oval (ca 620 µm long, 480 µm wide), gymnocyst presumably very narrow all around, cryptocyst absent; opesia large (ca 470 µm long, 370 µm wide), oval, slightly constricted in distal part ( Fig. 13B ); mural spine number unknown.

Remarks

With its large zooids, and especially its pronounced honeycomb-like pattern covering its entire frontal and ooecial surface, Calvetopora inflata gen. et comb. nov. is an outstanding species. Similar to species of Atlantisina gen. nov., but unlike C. otapostasis gen. et sp. nov. (see below) and species of Bathycyclopora gen. nov., the ooecium is produced by a kenozooid that is budded from the maternal zooid. Although the ooecium itself is hyperstomial and in the same position as in species of Atlantisina gen. nov., the ooecium is not quite as independent of the substratum but is formed from a small basal kenozooidal chamber that is invisible in frontal view, with the kenozooid barely touching the substratum ( Fig. 13E ). Furthermore, the ooecium of C. inflata gen. et comb. nov. differs from that of most other taxa described herein, including its other congeneric species (see below), in having an almost entirely membranous ectooecium.

Not only the central pores in the frontal shield but also the series of large pores visible along the lateral zooecial margin ( Fig. 13D ) are apparently not areolar pores, as they are situated above the ring scar and therefore within the umbonuloid part of the frontal shield, which means they are not connected to the zooid’s visceral coelom. Only the most distal ones are areolae, producing the pair of adventitious avicularia lateral to the orifice.

Ecology

The holotype encrusts a skeletal fragment of Lophelia pertusa that was recovered from 717 m depth.

Distribution

Calvetopora inflata gen. et comb. nov. has never been reported since the discovery of a single colony by Calvet (1906, 1907), although the same depth zone in the Gulf of Cádiz was resampled during the 1980s ( Harmelin & d’Hondt 1992).

Figures

Fig. 13. Calvetopora inflata (Calvet, 1906) gen. et comb. nov., Gulf of Cádiz, holotype (MNHN- IB-2008-2470). A. Overview of the periancestrular part of the colony. B. Close-up of the ancestrula and the first two autozooids. C. Maternal autozooids at the colony growth margin. D. Lateral view of an ovicellate zooid. E. Distal view of the colony growth margin showing the kenozooidal origin of the ooecia. F. Close-up of an avicularium. Scale bars: A, C = 500 µm; B, D = 200 µm; E = 300 µm; F = 50 µm.